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llvm-mirror/test/CodeGen/X86/vector-popcnt-128.ll

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Make utils/update_llc_test_checks.py note that the assertions are autogenerated. Also update existing test cases which appear to be generated by it and weren't modified (other than addition of the header) by rerunning it. llvm-svn: 253917
2015-11-23 22:33:58 +01:00
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s --check-prefix=ALL --check-prefix=SSE --check-prefix=SSE2
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+sse3 | FileCheck %s --check-prefix=ALL --check-prefix=SSE --check-prefix=SSE3
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+ssse3 | FileCheck %s --check-prefix=ALL --check-prefix=SSE --check-prefix=SSSE3
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+sse4.1 | FileCheck %s --check-prefix=ALL --check-prefix=SSE --check-prefix=SSE41
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx | FileCheck %s --check-prefix=ALL --check-prefix=AVX --check-prefix=AVX1
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx2 | FileCheck %s --check-prefix=ALL --check-prefix=AVX --check-prefix=AVX2
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <2 x i64> @testv2i64(<2 x i64> %in) nounwind {
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-LABEL: testv2i64:
; SSE2: # BB#0:
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrlq $1, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
; SSE2-NEXT: psubq %xmm1, %xmm0
; SSE2-NEXT: movdqa {{.*#+}} xmm1 = [3689348814741910323,3689348814741910323]
; SSE2-NEXT: movdqa %xmm0, %xmm2
; SSE2-NEXT: pand %xmm1, %xmm2
; SSE2-NEXT: psrlq $2, %xmm0
; SSE2-NEXT: pand %xmm1, %xmm0
; SSE2-NEXT: paddq %xmm2, %xmm0
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrlq $4, %xmm1
; SSE2-NEXT: paddq %xmm0, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE2-NEXT: pxor %xmm0, %xmm0
; SSE2-NEXT: psadbw %xmm0, %xmm1
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-NEXT: movdqa %xmm1, %xmm0
; SSE2-NEXT: retq
;
; SSE3-LABEL: testv2i64:
; SSE3: # BB#0:
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrlq $1, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
; SSE3-NEXT: psubq %xmm1, %xmm0
; SSE3-NEXT: movdqa {{.*#+}} xmm1 = [3689348814741910323,3689348814741910323]
; SSE3-NEXT: movdqa %xmm0, %xmm2
; SSE3-NEXT: pand %xmm1, %xmm2
; SSE3-NEXT: psrlq $2, %xmm0
; SSE3-NEXT: pand %xmm1, %xmm0
; SSE3-NEXT: paddq %xmm2, %xmm0
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrlq $4, %xmm1
; SSE3-NEXT: paddq %xmm0, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE3-NEXT: pxor %xmm0, %xmm0
; SSE3-NEXT: psadbw %xmm0, %xmm1
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE3-NEXT: movdqa %xmm1, %xmm0
; SSE3-NEXT: retq
;
; SSSE3-LABEL: testv2i64:
; SSSE3: # BB#0:
; SSSE3-NEXT: movdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSSE3-NEXT: movdqa %xmm0, %xmm2
; SSSE3-NEXT: pand %xmm1, %xmm2
; SSSE3-NEXT: movdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSSE3-NEXT: movdqa %xmm3, %xmm4
; SSSE3-NEXT: pshufb %xmm2, %xmm4
; SSSE3-NEXT: psrlw $4, %xmm0
; SSSE3-NEXT: pand %xmm1, %xmm0
; SSSE3-NEXT: pshufb %xmm0, %xmm3
; SSSE3-NEXT: paddb %xmm4, %xmm3
; SSSE3-NEXT: pxor %xmm0, %xmm0
; SSSE3-NEXT: psadbw %xmm3, %xmm0
; SSSE3-NEXT: retq
;
; SSE41-LABEL: testv2i64:
; SSE41: # BB#0:
; SSE41-NEXT: movdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSE41-NEXT: movdqa %xmm0, %xmm2
; SSE41-NEXT: pand %xmm1, %xmm2
; SSE41-NEXT: movdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSE41-NEXT: movdqa %xmm3, %xmm4
; SSE41-NEXT: pshufb %xmm2, %xmm4
; SSE41-NEXT: psrlw $4, %xmm0
; SSE41-NEXT: pand %xmm1, %xmm0
; SSE41-NEXT: pshufb %xmm0, %xmm3
; SSE41-NEXT: paddb %xmm4, %xmm3
; SSE41-NEXT: pxor %xmm0, %xmm0
; SSE41-NEXT: psadbw %xmm3, %xmm0
; SSE41-NEXT: retq
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
;
; AVX-LABEL: testv2i64:
; AVX: # BB#0:
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vmovdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm2
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vmovdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; AVX-NEXT: vpshufb %xmm2, %xmm3, %xmm2
; AVX-NEXT: vpsrlw $4, %xmm0, %xmm0
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vpshufb %xmm0, %xmm3, %xmm0
; AVX-NEXT: vpaddb %xmm2, %xmm0, %xmm0
; AVX-NEXT: vpxor %xmm1, %xmm1, %xmm1
[X86] Fix several issues related to X86's psadbw instruction. This patch fixes the following issues: 1. Fix the return type of X86psadbw: it should not be the same type of inputs. For vNi8 inputs the output should be vMi64, where M = N/8. 2. Fix the return type of int_x86_avx512_psad_bw_512 accordingly. 3. Fix the definiton of PSADBW, VPSADBW, and VPSADBWY accordingly. 4. Adjust the return type when building a DAG node of X86ISD::PSADBW type. 5. Update related tests. Differential revision: http://reviews.llvm.org/D14897 llvm-svn: 254010
2015-11-24 20:51:26 +01:00
; AVX-NEXT: vpsadbw %xmm1, %xmm0, %xmm0
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
; AVX-NEXT: retq
%out = call <2 x i64> @llvm.ctpop.v2i64(<2 x i64> %in)
ret <2 x i64> %out
}
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <4 x i32> @testv4i32(<4 x i32> %in) nounwind {
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-LABEL: testv4i32:
; SSE2: # BB#0:
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrld $1, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
; SSE2-NEXT: psubd %xmm1, %xmm0
; SSE2-NEXT: movdqa {{.*#+}} xmm1 = [858993459,858993459,858993459,858993459]
; SSE2-NEXT: movdqa %xmm0, %xmm2
; SSE2-NEXT: pand %xmm1, %xmm2
; SSE2-NEXT: psrld $2, %xmm0
; SSE2-NEXT: pand %xmm1, %xmm0
; SSE2-NEXT: paddd %xmm2, %xmm0
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrld $4, %xmm1
; SSE2-NEXT: paddd %xmm0, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE2-NEXT: pxor %xmm0, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-NEXT: movdqa %xmm1, %xmm2
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE2-NEXT: punpckhdq {{.*#+}} xmm2 = xmm2[2],xmm0[2],xmm2[3],xmm0[3]
; SSE2-NEXT: psadbw %xmm0, %xmm2
; SSE2-NEXT: punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
; SSE2-NEXT: psadbw %xmm0, %xmm1
; SSE2-NEXT: packuswb %xmm2, %xmm1
; SSE2-NEXT: movdqa %xmm1, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-NEXT: retq
;
; SSE3-LABEL: testv4i32:
; SSE3: # BB#0:
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrld $1, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
; SSE3-NEXT: psubd %xmm1, %xmm0
; SSE3-NEXT: movdqa {{.*#+}} xmm1 = [858993459,858993459,858993459,858993459]
; SSE3-NEXT: movdqa %xmm0, %xmm2
; SSE3-NEXT: pand %xmm1, %xmm2
; SSE3-NEXT: psrld $2, %xmm0
; SSE3-NEXT: pand %xmm1, %xmm0
; SSE3-NEXT: paddd %xmm2, %xmm0
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrld $4, %xmm1
; SSE3-NEXT: paddd %xmm0, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE3-NEXT: pxor %xmm0, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE3-NEXT: movdqa %xmm1, %xmm2
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE3-NEXT: punpckhdq {{.*#+}} xmm2 = xmm2[2],xmm0[2],xmm2[3],xmm0[3]
; SSE3-NEXT: psadbw %xmm0, %xmm2
; SSE3-NEXT: punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
; SSE3-NEXT: psadbw %xmm0, %xmm1
; SSE3-NEXT: packuswb %xmm2, %xmm1
; SSE3-NEXT: movdqa %xmm1, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE3-NEXT: retq
;
; SSSE3-LABEL: testv4i32:
; SSSE3: # BB#0:
; SSSE3-NEXT: movdqa {{.*#+}} xmm2 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSSE3-NEXT: movdqa %xmm0, %xmm3
; SSSE3-NEXT: pand %xmm2, %xmm3
; SSSE3-NEXT: movdqa {{.*#+}} xmm1 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSSE3-NEXT: movdqa %xmm1, %xmm4
; SSSE3-NEXT: pshufb %xmm3, %xmm4
; SSSE3-NEXT: psrlw $4, %xmm0
; SSSE3-NEXT: pand %xmm2, %xmm0
; SSSE3-NEXT: pshufb %xmm0, %xmm1
; SSSE3-NEXT: paddb %xmm4, %xmm1
; SSSE3-NEXT: pxor %xmm0, %xmm0
; SSSE3-NEXT: movdqa %xmm1, %xmm2
; SSSE3-NEXT: punpckhdq {{.*#+}} xmm2 = xmm2[2],xmm0[2],xmm2[3],xmm0[3]
; SSSE3-NEXT: psadbw %xmm0, %xmm2
; SSSE3-NEXT: punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
; SSSE3-NEXT: psadbw %xmm0, %xmm1
; SSSE3-NEXT: packuswb %xmm2, %xmm1
; SSSE3-NEXT: movdqa %xmm1, %xmm0
; SSSE3-NEXT: retq
;
; SSE41-LABEL: testv4i32:
; SSE41: # BB#0:
; SSE41-NEXT: movdqa {{.*#+}} xmm2 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSE41-NEXT: movdqa %xmm0, %xmm3
; SSE41-NEXT: pand %xmm2, %xmm3
; SSE41-NEXT: movdqa {{.*#+}} xmm1 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSE41-NEXT: movdqa %xmm1, %xmm4
; SSE41-NEXT: pshufb %xmm3, %xmm4
; SSE41-NEXT: psrlw $4, %xmm0
; SSE41-NEXT: pand %xmm2, %xmm0
; SSE41-NEXT: pshufb %xmm0, %xmm1
; SSE41-NEXT: paddb %xmm4, %xmm1
; SSE41-NEXT: pxor %xmm0, %xmm0
; SSE41-NEXT: movdqa %xmm1, %xmm2
; SSE41-NEXT: punpckhdq {{.*#+}} xmm2 = xmm2[2],xmm0[2],xmm2[3],xmm0[3]
; SSE41-NEXT: psadbw %xmm0, %xmm2
; SSE41-NEXT: punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
; SSE41-NEXT: psadbw %xmm0, %xmm1
; SSE41-NEXT: packuswb %xmm2, %xmm1
; SSE41-NEXT: movdqa %xmm1, %xmm0
; SSE41-NEXT: retq
;
; AVX-LABEL: testv4i32:
; AVX: # BB#0:
; AVX-NEXT: vmovdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm2
; AVX-NEXT: vmovdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; AVX-NEXT: vpshufb %xmm2, %xmm3, %xmm2
; AVX-NEXT: vpsrlw $4, %xmm0, %xmm0
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm0
; AVX-NEXT: vpshufb %xmm0, %xmm3, %xmm0
; AVX-NEXT: vpaddb %xmm2, %xmm0, %xmm0
; AVX-NEXT: vpxor %xmm1, %xmm1, %xmm1
; AVX-NEXT: vpunpckhdq {{.*#+}} xmm2 = xmm0[2],xmm1[2],xmm0[3],xmm1[3]
[X86] Fix several issues related to X86's psadbw instruction. This patch fixes the following issues: 1. Fix the return type of X86psadbw: it should not be the same type of inputs. For vNi8 inputs the output should be vMi64, where M = N/8. 2. Fix the return type of int_x86_avx512_psad_bw_512 accordingly. 3. Fix the definiton of PSADBW, VPSADBW, and VPSADBWY accordingly. 4. Adjust the return type when building a DAG node of X86ISD::PSADBW type. 5. Update related tests. Differential revision: http://reviews.llvm.org/D14897 llvm-svn: 254010
2015-11-24 20:51:26 +01:00
; AVX-NEXT: vpsadbw %xmm1, %xmm2, %xmm2
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vpunpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
[X86] Fix several issues related to X86's psadbw instruction. This patch fixes the following issues: 1. Fix the return type of X86psadbw: it should not be the same type of inputs. For vNi8 inputs the output should be vMi64, where M = N/8. 2. Fix the return type of int_x86_avx512_psad_bw_512 accordingly. 3. Fix the definiton of PSADBW, VPSADBW, and VPSADBWY accordingly. 4. Adjust the return type when building a DAG node of X86ISD::PSADBW type. 5. Update related tests. Differential revision: http://reviews.llvm.org/D14897 llvm-svn: 254010
2015-11-24 20:51:26 +01:00
; AVX-NEXT: vpsadbw %xmm1, %xmm0, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vpackuswb %xmm2, %xmm0, %xmm0
; AVX-NEXT: retq
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
%out = call <4 x i32> @llvm.ctpop.v4i32(<4 x i32> %in)
ret <4 x i32> %out
}
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <8 x i16> @testv8i16(<8 x i16> %in) nounwind {
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-LABEL: testv8i16:
; SSE2: # BB#0:
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrlw $1, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
; SSE2-NEXT: psubw %xmm1, %xmm0
; SSE2-NEXT: movdqa {{.*#+}} xmm1 = [13107,13107,13107,13107,13107,13107,13107,13107]
; SSE2-NEXT: movdqa %xmm0, %xmm2
; SSE2-NEXT: pand %xmm1, %xmm2
; SSE2-NEXT: psrlw $2, %xmm0
; SSE2-NEXT: pand %xmm1, %xmm0
; SSE2-NEXT: paddw %xmm2, %xmm0
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrlw $4, %xmm1
; SSE2-NEXT: paddw %xmm0, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
; SSE2-NEXT: movdqa %xmm1, %xmm0
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE2-NEXT: psllw $8, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-NEXT: paddb %xmm1, %xmm0
; SSE2-NEXT: psrlw $8, %xmm0
; SSE2-NEXT: retq
;
; SSE3-LABEL: testv8i16:
; SSE3: # BB#0:
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrlw $1, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
; SSE3-NEXT: psubw %xmm1, %xmm0
; SSE3-NEXT: movdqa {{.*#+}} xmm1 = [13107,13107,13107,13107,13107,13107,13107,13107]
; SSE3-NEXT: movdqa %xmm0, %xmm2
; SSE3-NEXT: pand %xmm1, %xmm2
; SSE3-NEXT: psrlw $2, %xmm0
; SSE3-NEXT: pand %xmm1, %xmm0
; SSE3-NEXT: paddw %xmm2, %xmm0
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrlw $4, %xmm1
; SSE3-NEXT: paddw %xmm0, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
; SSE3-NEXT: movdqa %xmm1, %xmm0
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE3-NEXT: psllw $8, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE3-NEXT: paddb %xmm1, %xmm0
; SSE3-NEXT: psrlw $8, %xmm0
; SSE3-NEXT: retq
;
; SSSE3-LABEL: testv8i16:
; SSSE3: # BB#0:
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSSE3-NEXT: movdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSSE3-NEXT: movdqa %xmm0, %xmm2
; SSSE3-NEXT: pand %xmm1, %xmm2
; SSSE3-NEXT: movdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSSE3-NEXT: movdqa %xmm3, %xmm4
; SSSE3-NEXT: pshufb %xmm2, %xmm4
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSSE3-NEXT: psrlw $4, %xmm0
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSSE3-NEXT: pand %xmm1, %xmm0
; SSSE3-NEXT: pshufb %xmm0, %xmm3
; SSSE3-NEXT: paddb %xmm4, %xmm3
; SSSE3-NEXT: movdqa %xmm3, %xmm0
; SSSE3-NEXT: psllw $8, %xmm0
; SSSE3-NEXT: paddb %xmm3, %xmm0
; SSSE3-NEXT: psrlw $8, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSSE3-NEXT: retq
;
; SSE41-LABEL: testv8i16:
; SSE41: # BB#0:
; SSE41-NEXT: movdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSE41-NEXT: movdqa %xmm0, %xmm2
; SSE41-NEXT: pand %xmm1, %xmm2
; SSE41-NEXT: movdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSE41-NEXT: movdqa %xmm3, %xmm4
; SSE41-NEXT: pshufb %xmm2, %xmm4
; SSE41-NEXT: psrlw $4, %xmm0
; SSE41-NEXT: pand %xmm1, %xmm0
; SSE41-NEXT: pshufb %xmm0, %xmm3
; SSE41-NEXT: paddb %xmm4, %xmm3
; SSE41-NEXT: movdqa %xmm3, %xmm0
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; SSE41-NEXT: psllw $8, %xmm0
; SSE41-NEXT: paddb %xmm3, %xmm0
; SSE41-NEXT: psrlw $8, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE41-NEXT: retq
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
;
; AVX-LABEL: testv8i16:
; AVX: # BB#0:
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vmovdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
[x86] Restructure the parallel bitmath lowering of popcount into a separate routine, generalize it to work for all the integer vector sizes, and do general code cleanups. This dramatically improves lowerings of byte and short element vector popcount, but more importantly it will make the introduction of the LUT-approach much cleaner. The biggest cleanup I've done is to just force the legalizer to do the bitcasting we need. We run these iteratively now and it makes the code much simpler IMO. Other changes were minor, and mostly naming and splitting things up in a way that makes it more clear what is going on. The other significant change is to use a different final horizontal sum approach. This is the same number of instructions as the old method, but shifts left instead of right so that we can clear everything but the final sum with a single shift right. This seems likely better than a mask which will usually have to read the mask from memory. It is certaily fewer u-ops. Also, this will be temporary. This and the LUT approach share the need of horizontal adds to finish the computation, and we have more clever approaches than this one that I'll switch over to. llvm-svn: 238635
2015-05-30 05:20:55 +02:00
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm2
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vmovdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; AVX-NEXT: vpshufb %xmm2, %xmm3, %xmm2
; AVX-NEXT: vpsrlw $4, %xmm0, %xmm0
[x86] Restructure the parallel bitmath lowering of popcount into a separate routine, generalize it to work for all the integer vector sizes, and do general code cleanups. This dramatically improves lowerings of byte and short element vector popcount, but more importantly it will make the introduction of the LUT-approach much cleaner. The biggest cleanup I've done is to just force the legalizer to do the bitcasting we need. We run these iteratively now and it makes the code much simpler IMO. Other changes were minor, and mostly naming and splitting things up in a way that makes it more clear what is going on. The other significant change is to use a different final horizontal sum approach. This is the same number of instructions as the old method, but shifts left instead of right so that we can clear everything but the final sum with a single shift right. This seems likely better than a mask which will usually have to read the mask from memory. It is certaily fewer u-ops. Also, this will be temporary. This and the LUT approach share the need of horizontal adds to finish the computation, and we have more clever approaches than this one that I'll switch over to. llvm-svn: 238635
2015-05-30 05:20:55 +02:00
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vpshufb %xmm0, %xmm3, %xmm0
; AVX-NEXT: vpaddb %xmm2, %xmm0, %xmm0
[x86] Unify the horizontal adding used for popcount lowering taking the best approach of each. For vNi16, we use SHL + ADD + SRL pattern that seem easily the best. For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases there is a huge improvement with this in IACA's estimated throughput -- over 2x higher throughput!!!! -- but the measurements are too good to be true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks slightly faster, but I'm not sure I believe any of the measurements at this point. Both are the exact same uops though. Hard to be confident of anything past that. If anyone wants to collect very detailed (Agner-level) timings with the result of this patch, or with the i32 case replaced with SHL + ADD + SHl + ADD + SRL, I'd be very interested. Note that you'll need to test it on both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as I saw unique behavior in each of these buckets with IACA all of which should be checked against measured performance. But this patch is still a useful improvement by dropping duplicate work and getting the much nicer PSADBW lowering for v2i64. I'd still like to rephrase this in terms of generic horizontal sum. It's a bit lame to have a special case of that just for popcount. llvm-svn: 238652
2015-05-30 12:35:03 +02:00
; AVX-NEXT: vpsllw $8, %xmm0, %xmm1
; AVX-NEXT: vpaddb %xmm0, %xmm1, %xmm0
; AVX-NEXT: vpsrlw $8, %xmm0, %xmm0
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
; AVX-NEXT: retq
%out = call <8 x i16> @llvm.ctpop.v8i16(<8 x i16> %in)
ret <8 x i16> %out
}
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <16 x i8> @testv16i8(<16 x i8> %in) nounwind {
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-LABEL: testv16i8:
; SSE2: # BB#0:
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrlw $1, %xmm1
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
; SSE2-NEXT: psubb %xmm1, %xmm0
; SSE2-NEXT: movdqa {{.*#+}} xmm1 = [51,51,51,51,51,51,51,51,51,51,51,51,51,51,51,51]
; SSE2-NEXT: movdqa %xmm0, %xmm2
; SSE2-NEXT: pand %xmm1, %xmm2
; SSE2-NEXT: psrlw $2, %xmm0
; SSE2-NEXT: pand %xmm1, %xmm0
; SSE2-NEXT: paddb %xmm2, %xmm0
; SSE2-NEXT: movdqa %xmm0, %xmm1
; SSE2-NEXT: psrlw $4, %xmm1
; SSE2-NEXT: paddb %xmm0, %xmm1
[x86] Restore the bitcasts I removed when refactoring this to avoid shifting vectors of bytes as x86 doesn't have direct support for that. This removes a bunch of redundant masking in the generated code for SSE2 and SSE3. In order to avoid the really significant code size growth this would have triggered, I also factored the completely repeatative logic for shifting and masking into two lambdas which in turn makes all of this much easier to read IMO. llvm-svn: 238637
2015-05-30 06:05:11 +02:00
; SSE2-NEXT: pand {{.*}}(%rip), %xmm1
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE2-NEXT: movdqa %xmm1, %xmm0
; SSE2-NEXT: retq
;
; SSE3-LABEL: testv16i8:
; SSE3: # BB#0:
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrlw $1, %xmm1
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
; SSE3-NEXT: psubb %xmm1, %xmm0
; SSE3-NEXT: movdqa {{.*#+}} xmm1 = [51,51,51,51,51,51,51,51,51,51,51,51,51,51,51,51]
; SSE3-NEXT: movdqa %xmm0, %xmm2
; SSE3-NEXT: pand %xmm1, %xmm2
; SSE3-NEXT: psrlw $2, %xmm0
; SSE3-NEXT: pand %xmm1, %xmm0
; SSE3-NEXT: paddb %xmm2, %xmm0
; SSE3-NEXT: movdqa %xmm0, %xmm1
; SSE3-NEXT: psrlw $4, %xmm1
; SSE3-NEXT: paddb %xmm0, %xmm1
[x86] Restore the bitcasts I removed when refactoring this to avoid shifting vectors of bytes as x86 doesn't have direct support for that. This removes a bunch of redundant masking in the generated code for SSE2 and SSE3. In order to avoid the really significant code size growth this would have triggered, I also factored the completely repeatative logic for shifting and masking into two lambdas which in turn makes all of this much easier to read IMO. llvm-svn: 238637
2015-05-30 06:05:11 +02:00
; SSE3-NEXT: pand {{.*}}(%rip), %xmm1
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; SSE3-NEXT: movdqa %xmm1, %xmm0
; SSE3-NEXT: retq
;
; SSSE3-LABEL: testv16i8:
; SSSE3: # BB#0:
; SSSE3-NEXT: movdqa {{.*#+}} xmm2 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSSE3-NEXT: movdqa %xmm0, %xmm3
; SSSE3-NEXT: pand %xmm2, %xmm3
; SSSE3-NEXT: movdqa {{.*#+}} xmm1 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSSE3-NEXT: movdqa %xmm1, %xmm4
; SSSE3-NEXT: pshufb %xmm3, %xmm4
; SSSE3-NEXT: psrlw $4, %xmm0
; SSSE3-NEXT: pand %xmm2, %xmm0
; SSSE3-NEXT: pshufb %xmm0, %xmm1
; SSSE3-NEXT: paddb %xmm4, %xmm1
; SSSE3-NEXT: movdqa %xmm1, %xmm0
; SSSE3-NEXT: retq
;
; SSE41-LABEL: testv16i8:
; SSE41: # BB#0:
; SSE41-NEXT: movdqa {{.*#+}} xmm2 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
; SSE41-NEXT: movdqa %xmm0, %xmm3
; SSE41-NEXT: pand %xmm2, %xmm3
; SSE41-NEXT: movdqa {{.*#+}} xmm1 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; SSE41-NEXT: movdqa %xmm1, %xmm4
; SSE41-NEXT: pshufb %xmm3, %xmm4
; SSE41-NEXT: psrlw $4, %xmm0
; SSE41-NEXT: pand %xmm2, %xmm0
; SSE41-NEXT: pshufb %xmm0, %xmm1
; SSE41-NEXT: paddb %xmm4, %xmm1
; SSE41-NEXT: movdqa %xmm1, %xmm0
; SSE41-NEXT: retq
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
;
; AVX-LABEL: testv16i8:
; AVX: # BB#0:
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vmovdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
[x86] Restructure the parallel bitmath lowering of popcount into a separate routine, generalize it to work for all the integer vector sizes, and do general code cleanups. This dramatically improves lowerings of byte and short element vector popcount, but more importantly it will make the introduction of the LUT-approach much cleaner. The biggest cleanup I've done is to just force the legalizer to do the bitcasting we need. We run these iteratively now and it makes the code much simpler IMO. Other changes were minor, and mostly naming and splitting things up in a way that makes it more clear what is going on. The other significant change is to use a different final horizontal sum approach. This is the same number of instructions as the old method, but shifts left instead of right so that we can clear everything but the final sum with a single shift right. This seems likely better than a mask which will usually have to read the mask from memory. It is certaily fewer u-ops. Also, this will be temporary. This and the LUT approach share the need of horizontal adds to finish the computation, and we have more clever approaches than this one that I'll switch over to. llvm-svn: 238635
2015-05-30 05:20:55 +02:00
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm2
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vmovdqa {{.*#+}} xmm3 = [0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4]
; AVX-NEXT: vpshufb %xmm2, %xmm3, %xmm2
; AVX-NEXT: vpsrlw $4, %xmm0, %xmm0
[x86] Restructure the parallel bitmath lowering of popcount into a separate routine, generalize it to work for all the integer vector sizes, and do general code cleanups. This dramatically improves lowerings of byte and short element vector popcount, but more importantly it will make the introduction of the LUT-approach much cleaner. The biggest cleanup I've done is to just force the legalizer to do the bitcasting we need. We run these iteratively now and it makes the code much simpler IMO. Other changes were minor, and mostly naming and splitting things up in a way that makes it more clear what is going on. The other significant change is to use a different final horizontal sum approach. This is the same number of instructions as the old method, but shifts left instead of right so that we can clear everything but the final sum with a single shift right. This seems likely better than a mask which will usually have to read the mask from memory. It is certaily fewer u-ops. Also, this will be temporary. This and the LUT approach share the need of horizontal adds to finish the computation, and we have more clever approaches than this one that I'll switch over to. llvm-svn: 238635
2015-05-30 05:20:55 +02:00
; AVX-NEXT: vpand %xmm1, %xmm0, %xmm0
[x86] Implement a faster vector population count based on the PSHUFB in-register LUT technique. Summary: A description of this technique can be found here: http://wm.ite.pl/articles/sse-popcount.html The core of the idea is to use an in-register lookup table and the PSHUFB instruction to compute the population count for the low and high nibbles of each byte, and then to use horizontal sums to aggregate these into vector population counts with wider element types. On x86 there is an instruction that will directly compute the horizontal sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily. Various tricks are used to get vNi32 and vNi16 from the vNi8 that the LUT computes. The base implemantion of this, and most of the work, was done by Bruno in a follow up to D6531. See Bruno's detailed post there for lots of timing information about these changes. I have extended Bruno's patch in the following ways: 0) I committed the new tests with baseline sequences so this shows a diff, and regenerated the tests using the update scripts. 1) Bruno had noticed and mentioned in IRC a redundant mask that I removed. 2) I introduced a particular optimization for the i32 vector cases where we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD + PSADBW to compute doubled high i32 popcounts. This takes advantage of the fact that to line up the high i32 popcounts we have to shift them anyways, and we can shift them by one fewer bit to effectively divide the count by two. While the PSHUFD based horizontal add is no faster, it doesn't require registers or load traffic the way a mask would, and provides more ILP as it happens on different ports with high throughput. 3) I did some code cleanups throughout to simplify the implementation logic. 4) I refactored it to continue to use the parallel bitmath lowering when SSSE3 is not available to preserve the performance of that version on SSE2 targets where it is still much better than scalarizing as we'll still do a bitmath implementation of popcount even in scalar code there. With #1 and #2 above, I analyzed the result in IACA for sandybridge, ivybridge, and haswell. In every case I measured, the throughput is the same or better using the LUT lowering, even v2i64 and v4i64, and even compared with using the native popcnt instruction! The latency of the LUT lowering is often higher than the latency of the scalarized popcnt instruction sequence, but I think those latency measurements are deeply misleading. Keeping the operation fully in the vector unit and having many chances for increased throughput seems much more likely to win. With this, we can lower every integer vector popcount implementation using the LUT strategy if we have SSSE3 or better (and thus have PSHUFB). I've updated the operation lowering to reflect this. This also fixes an issue where we were scalarizing horribly some AVX lowerings. Finally, there are some remaining cleanups. There is duplication between the two techniques in how they perform the horizontal sum once the byte population count is computed. I'm going to factor and merge those two in a separate follow-up commit. Differential Revision: http://reviews.llvm.org/D10084 llvm-svn: 238636
2015-05-30 05:20:59 +02:00
; AVX-NEXT: vpshufb %xmm0, %xmm3, %xmm0
; AVX-NEXT: vpaddb %xmm2, %xmm0, %xmm0
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
; AVX-NEXT: retq
%out = call <16 x i8> @llvm.ctpop.v16i8(<16 x i8> %in)
ret <16 x i8> %out
}
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <2 x i64> @foldv2i64() nounwind {
[DAGCombiner] Added CTPOP vector constant folding support. Added tests to the existing SSE/AVX test files. llvm-svn: 239252
2015-06-07 17:37:14 +02:00
; SSE-LABEL: foldv2i64:
; SSE: # BB#0:
; SSE-NEXT: movaps {{.*#+}} xmm0 = [1,64]
; SSE-NEXT: retq
;
; AVX-LABEL: foldv2i64:
; AVX: # BB#0:
; AVX-NEXT: vmovaps {{.*#+}} xmm0 = [1,64]
; AVX-NEXT: retq
%out = call <2 x i64> @llvm.ctpop.v2i64(<2 x i64> <i64 256, i64 -1>)
ret <2 x i64> %out
}
Fixed line endings llvm-svn: 239253
2015-06-07 18:09:48 +02:00
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <4 x i32> @foldv4i32() nounwind {
[DAGCombiner] Added CTPOP vector constant folding support. Added tests to the existing SSE/AVX test files. llvm-svn: 239252
2015-06-07 17:37:14 +02:00
; SSE-LABEL: foldv4i32:
; SSE: # BB#0:
; SSE-NEXT: movaps {{.*#+}} xmm0 = [1,32,0,8]
; SSE-NEXT: retq
;
; AVX-LABEL: foldv4i32:
; AVX: # BB#0:
; AVX-NEXT: vmovaps {{.*#+}} xmm0 = [1,32,0,8]
; AVX-NEXT: retq
%out = call <4 x i32> @llvm.ctpop.v4i32(<4 x i32> <i32 256, i32 -1, i32 0, i32 255>)
ret <4 x i32> %out
}
Fixed line endings llvm-svn: 239253
2015-06-07 18:09:48 +02:00
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <8 x i16> @foldv8i16() nounwind {
[DAGCombiner] Added CTPOP vector constant folding support. Added tests to the existing SSE/AVX test files. llvm-svn: 239252
2015-06-07 17:37:14 +02:00
; SSE-LABEL: foldv8i16:
; SSE: # BB#0:
; SSE-NEXT: movaps {{.*#+}} xmm0 = [1,16,0,8,0,3,2,3]
; SSE-NEXT: retq
;
; AVX-LABEL: foldv8i16:
; AVX: # BB#0:
; AVX-NEXT: vmovaps {{.*#+}} xmm0 = [1,16,0,8,0,3,2,3]
; AVX-NEXT: retq
%out = call <8 x i16> @llvm.ctpop.v8i16(<8 x i16> <i16 256, i16 -1, i16 0, i16 255, i16 -65536, i16 7, i16 24, i16 88>)
ret <8 x i16> %out
}
Fixed line endings llvm-svn: 239253
2015-06-07 18:09:48 +02:00
[X86] Updated vector popcnt tests. Added vec512 tests. llvm-svn: 246921
2015-09-05 11:59:59 +02:00
define <16 x i8> @foldv16i8() nounwind {
[DAGCombiner] Added CTPOP vector constant folding support. Added tests to the existing SSE/AVX test files. llvm-svn: 239252
2015-06-07 17:37:14 +02:00
; SSE-LABEL: foldv16i8:
; SSE: # BB#0:
; SSE-NEXT: movaps {{.*#+}} xmm0 = [0,8,0,8,0,3,2,3,7,7,1,1,1,1,1,1]
; SSE-NEXT: retq
;
; AVX-LABEL: foldv16i8:
; AVX: # BB#0:
; AVX-NEXT: vmovaps {{.*#+}} xmm0 = [0,8,0,8,0,3,2,3,7,7,1,1,1,1,1,1]
; AVX-NEXT: retq
%out = call <16 x i8> @llvm.ctpop.v16i8(<16 x i8> <i8 256, i8 -1, i8 0, i8 255, i8 -65536, i8 7, i8 24, i8 88, i8 -2, i8 254, i8 1, i8 2, i8 4, i8 8, i8 16, i8 32>)
ret <16 x i8> %out
}
[x86] Move the vector popcount tests into non-ISA files, and instead organize them by the width of vector. This makes it a lot easier to see that we're covering all of the vector types but not doing so excessively. This also adds tests across the spectrum of SSE versions in addition to the AVX versions. If you're really tired of seeing the *massive* sprawl of scalarized code for this, don't worry, I'm just about to land Bruno's patch that dramatically improve the situation for SSSE3 and newer. llvm-svn: 238520
2015-05-29 00:46:48 +02:00
declare <2 x i64> @llvm.ctpop.v2i64(<2 x i64>)
declare <4 x i32> @llvm.ctpop.v4i32(<4 x i32>)
declare <8 x i16> @llvm.ctpop.v8i16(<8 x i16>)
declare <16 x i8> @llvm.ctpop.v16i8(<16 x i8>)
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