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Commit Graph

27600 Commits

Author SHA1 Message Date
Bruno Cardoso Lopes
afb4b15ab3 [InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr
The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. This fixes an assertion crash.

Differential Revision: http://reviews.llvm.org/D6644

rdar://problem/19191835

llvm-svn: 224574
2014-12-19 14:23:15 +00:00
Juergen Ributzka
87fbd21d74 [Object] Don't crash on empty export lists.
Summary: This fixes the exports iterator if the export list is empty.

Reviewers: Bigcheese, kledzik

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6732

llvm-svn: 224563
2014-12-19 02:31:01 +00:00
Colin LeMahieu
ab28d2b2e6 [Hexagon] Adding loop0/1 sp0/1/2loop0 instructions.
llvm-svn: 224556
2014-12-19 00:06:53 +00:00
David Majnemer
273acc7601 ConstantFold: Shifting undef by zero results in undef
llvm-svn: 224553
2014-12-18 23:54:43 +00:00
Colin LeMahieu
069ff897d0 Reverting 224550, was not ready for commit.
llvm-svn: 224552
2014-12-18 23:36:15 +00:00
Colin LeMahieu
260ab2afbd [Hexagon] Adding loop0/1 sp0/1/2loop0 instructions.
llvm-svn: 224550
2014-12-18 23:27:51 +00:00
Kevin Enderby
61ee8e90b3 Add printing the LC_SUB_UMBRELLA load command with llvm-objdump’s -private-headers.
llvm-svn: 224548
2014-12-18 23:13:26 +00:00
Kevin Enderby
5c57c31db7 Add printing the LC_SUB_FRAMEWORK load command with llvm-objdump’s -private-headers.
llvm-svn: 224534
2014-12-18 19:24:35 +00:00
Jozef Kolek
cd3fff8406 [mips][microMIPS] Fix bugs related to atomic SC/LL instructions
Fix bugs related to atomic microMIPS SC/LL instructions: While expanding atomic
operations the mips32r2 encoding was emitted instead of microMIPS.

Differential Revision: http://reviews.llvm.org/D6659

llvm-svn: 224524
2014-12-18 16:39:29 +00:00
Saleem Abdulrasool
82b43a5896 ARM: fix an off-by-one in the register list access
Fix an off-by-one access introduced in 224502 for push.w and pop.w with single
register operands.  Add test cases for both scenarios.

Thanks to Asiri Rathnayake for pointing out the failure!

llvm-svn: 224521
2014-12-18 16:16:53 +00:00
Toma Tabacu
9813b67bea [mips] Clean up the CodeGen/Mips/inlineasmmemop.ll test. NFC.
Summary:
Improve comments and remove a redundant attribute list.
There are no functional changes (to the CHECK's or to the code).

Part of these changes were suggested in http://reviews.llvm.org/D6637.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6705

llvm-svn: 224517
2014-12-18 13:03:51 +00:00
Robert Khasanov
0bf2db97cb [AVX512] Enable FP arithmetic lowering for AVX512VL subsets.
Added RegOp2MemOpTable4 to transform 4th operand from register to memory in merge-masked versions of instructions. 
Added lowering tests.

llvm-svn: 224516
2014-12-18 12:28:22 +00:00
Saleem Abdulrasool
0b2c7d3514 ARM: improve instruction validation for thumb mode
The ARM Architecture Reference Manual states the following:
  LDM{,IA,DB}:
    The SP cannot be in the list.
    The PC can be in the list.
    If the PC is in the list:
      • the LR must not be in the list
      • the instruction must be either outside any IT block, or the last
        instruction in an IT block.
  POP:
    The PC can be in the list.
    If the PC is in the list:
      • the LR must not be in the list
      • the instruction must be either outside any IT block, or the last
        instruction in an IT block.
  PUSH:
    The SP and PC can be in the list in ARM instructions, but not in Thumb
    instructions.
  STM:{,IA,DB}:
    The SP and PC can be in the list in ARM instructions, but not in Thumb
    instructions.

llvm-svn: 224502
2014-12-18 05:24:38 +00:00
Saleem Abdulrasool
f6fc6efa8f test: avoid unnecessary temporary files
Use pipes and redirect the error output to FileCheck directly.  NFC.

llvm-svn: 224501
2014-12-18 05:24:32 +00:00
Eric Christopher
31f514defb Add a new string member to the TargetOptions struct for the name
of the abi we should be using. For targets that don't use the
option there's no change, otherwise this allows external users
to set the ABI via string and avoid some of the -backend-option
pain in clang.

Use this option to move the ABI for the ARM port from the
Subtarget to the TargetMachine and update the testcases
accordingly since it's no longer valid to set via -mattr.

llvm-svn: 224492
2014-12-18 02:20:58 +00:00
Eric Christopher
aa3a65c590 Model ARM backend ABI selection after the front end code doing the
same. This will change the "bare metal" ABI from APCS to AAPCS.

The only difference between the front and back end code is that
the code for Triple::GNU was added for environment. That will migrate
to the front end shortly.

Tests updated with the ABI they were originally testing in the case
of bare metal (e.g. -mtriple armv7) or with a -gnu for arm-linux
triples.

llvm-svn: 224489
2014-12-18 02:08:45 +00:00
Duncan P. N. Exon Smith
4c1c83ec6c Reapply "Linker: Drop superseded subprograms"
This reverts commit r224416, reapplying r224389.  The buildbots hadn't
recovered after my revert, waiting until David reverted a couple of his
commits.  It looks like it was just bad timing (where we were both
modifying code related to the same assertion).  Trying again...

Here's the original text:

    When a function gets replaced by `ModuleLinker`, drop superseded
    subprograms.  This ensures that the "first" subprogram pointing at a
    function is the same one that `!dbg` references point at.

    This is a stop-gap fix for PR21910.  Notably, this fixes Release+Asserts
    bootstraps that are currently asserting out in
    `LexicalScopes::initialize()` due to the explicit instantiations in
    `lib/IR/Dominators.cpp` eventually getting replaced by -argpromotion.

llvm-svn: 224487
2014-12-18 01:05:33 +00:00
Kevin Enderby
7c66bebcdf Add printing the LC_LINKER_OPTION load command with llvm-objdump’s -private-headers.
Also corrected the name of the load command to not end in an ’S’ as well as corrected
the name of the MachO::linker_option_command struct and other places that had the
word option as plural which did not match the Mac OS X headers.

llvm-svn: 224485
2014-12-18 00:53:40 +00:00
Matt Arsenault
7f117abc99 R600/SI: Fix f64 inline immediates
llvm-svn: 224458
2014-12-17 21:04:08 +00:00
Jingyue Wu
17566f954b [NVPTX] Fix bugs related to isSingleValueType
Summary:
With isSingleValueType starting to treat vector types as single-value types,
code that uses this interface needs to be updated.

Test Plan:
vector-global.ll
nvcl-param-align.ll

Reviewers: jholewinski

Reviewed By: jholewinski

Subscribers: llvm-commits, meheff, eliben, jholewinski

Differential Revision: http://reviews.llvm.org/D6573

llvm-svn: 224440
2014-12-17 17:59:04 +00:00
Timur Iskhodzhanov
2f4f744301 Fix CR/LF line endings in test case
llvm-svn: 224437
2014-12-17 17:52:12 +00:00
Saleem Abdulrasool
3a1f685ef5 ARM: correct an off-by-one in an assert
The assert was off-by-one, resulting in failures for valid input.

Thanks to Asiri Rathnayake for pointing out the failure!

llvm-svn: 224432
2014-12-17 16:17:44 +00:00
Michael Kuperstein
3790301d73 [DAGCombine] Slightly improve lowering of BUILD_VECTOR into a shuffle.
This handles the case of a BUILD_VECTOR being constructed out of elements extracted from a vector twice the size of the result vector. Previously this was always scalarized. Now, we try to construct a shuffle node that feeds on extract_subvectors.

This fixes PR15872 and provides a partial fix for PR21711.

Differential Revision: http://reviews.llvm.org/D6678

llvm-svn: 224429
2014-12-17 12:32:17 +00:00
Toma Tabacu
311b69b658 [mips] Set GCC-compatible MIPS asssembler options before inline asm blocks.
Summary:
When generating MIPS assembly, LLVM always overrides the default assembler options by emitting the '.set noreorder', '.set nomacro' and '.set noat' directives,
while GCC uses the default options if an assembly-level function contains inline assembly code.

This becomes a problem when the code generated by LLVM is interleaved with inline assembly which assumes GCC-like assembler options (from Linux, for example).

This patch fixes these conflicts by setting the appropriate assembler options at the beginning of an inline asm block and popping them at the end.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6637

llvm-svn: 224425
2014-12-17 10:56:16 +00:00
Suyog Sarda
ea83428380 Revert 224119 "This patch recognizes (+ (+ v0, v1) (+ v2, v3)), reorders them for bundling into vector of loads,
and vectorizes it." 

This was re-ordering floating point data types resulting in mismatch in output.

llvm-svn: 224424
2014-12-17 10:34:27 +00:00
Yaron Keren
48c54e0ea2 Teach lit.cfg to recognize -windows-gnu in addition to -mingw32.
llvm-svn: 224421
2014-12-17 09:55:15 +00:00
Elena Demikhovsky
537a8ee728 Added 5 more tests related to sink store revision 224247
- by Ella Bolshinsky

http://reviews.llvm.org/D6420

llvm-svn: 224418
2014-12-17 08:12:59 +00:00
Erik Eckstein
042c032147 Strength reduce intrinsics with overflow into regular arithmetic operations if possible.
Some intrinsics, like s/uadd.with.overflow and umul.with.overflow, are already strength reduced.
This change adds other arithmetic intrinsics: s/usub.with.overflow, smul.with.overflow.
It completes the work on PR20194.

llvm-svn: 224417
2014-12-17 07:29:19 +00:00
Duncan P. N. Exon Smith
759b4ed45d Revert "Linker: Drop superseded subprograms"
This reverts commit r224389.  Based on feedback from the bots, the
assertion seems to be going off *more* often, not less (previously I was
just seeing it in an internal bootstrap, now it's happening in public
builds too).

http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/936/
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/5325

Reverting in order to investigate.

llvm-svn: 224416
2014-12-17 07:27:31 +00:00
Justin Hibbits
9dd5e8fee1 Add parsing of 'foo@local".
Summary:
Currently, it supports generating, but not parsing, this expression.
Test added as well.

Test Plan: New test added, no regressions due to this.

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6672

llvm-svn: 224415
2014-12-17 06:23:35 +00:00
Duncan P. N. Exon Smith
1a57e7746d llvm-lto: Add testing coverage for local contexts
Add coverage in `llvm-lto` for the API exposed by libLTO to create
modules in local contexts.

The goal here isn't to test the symbol-related API extensively, just to
confirm that these modules work at all.  (I'll be shifting code around
soon that should be NFC and I realized there was no test coverage.)

llvm-svn: 224408
2014-12-17 02:00:38 +00:00
David Majnemer
fe299df41a InstSimplify: shl nsw/nuw undef, %V -> undef
We can always choose an value for undef which might cause %V to shift
out an important bit except for one case, when %V is zero.

However, shl behaves like an identity function when the right hand side
is zero.

llvm-svn: 224405
2014-12-17 01:54:33 +00:00
Quentin Colombet
5896cdb9ff [CodeGenPrepare] Reapply r224351 with a fix for the assertion failure:
The type promotion helper does not support vector type, so when make
such it does not kick in in such cases.

Original commit message:
[CodeGenPrepare] Move sign/zero extensions near loads using type promotion.

This patch extends the optimization in CodeGenPrepare that moves a sign/zero
extension near a load when the target can combine them. The optimization may
promote any operations between the extension and the load to make that possible.

Although this optimization may be beneficial for all targets, in particular
AArch64, this is enabled for X86 only as I have not benchmarked it for other
targets yet.


** Context **

Most targets feature extended loads, i.e., loads that perform a zero or sign
extension for free. In that context it is interesting to expose such pattern in
CodeGenPrepare so that the instruction selection pass can form such loads.
Sometimes, this pattern is blocked because of instructions between the load and
the extension. When those instructions are promotable to the extended type, we
can expose this pattern.


** Motivating Example **

Let us consider an example:
define void @foo(i8* %addr1, i32* %addr2, i8 %a, i32 %b) {
  %ld = load i8* %addr1
  %zextld = zext i8 %ld to i32
  %ld2 = load i32* %addr2
  %add = add nsw i32 %ld2, %zextld
  %sextadd = sext i32 %add to i64
  %zexta = zext i8 %a to i32
  %addza = add nsw i32 %zexta, %zextld
  %sextaddza = sext i32 %addza to i64
  %addb = add nsw i32 %b, %zextld
  %sextaddb = sext i32 %addb to i64
  call void @dummy(i64 %sextadd, i64 %sextaddza, i64 %sextaddb)
  ret void
}

As it is, this IR generates the following assembly on x86_64:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movl  (%rsi), %es      # plain load
  addl  %eax, %esi       # 32-bit add
  movslq  %esi, %rdi     # sign extend the result of add
  movzbl  %dl, %edx      # zero extend the first argument
  addl  %eax, %edx       # 32-bit add
  movslq  %edx, %rsi     # sign extend the result of add
  addl  %eax, %ecx       # 32-bit add
  movslq  %ecx, %rdx     # sign extend the result of add
[...]
The throughput of this sequence is 7.45 cycles on Ivy Bridge according to IACA.

Now, by promoting the additions to form more extended loads we would generate:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movslq  (%rsi), %rdi   # sign-extended load
  addq  %rax, %rdi       # 64-bit add
  movzbl  %dl, %esi      # zero extend the first argument
  addq  %rax, %rsi       # 64-bit add
  movslq  %ecx, %rdx     # sign extend the second argument
  addq  %rax, %rdx       # 64-bit add
[...]
The throughput of this sequence is 6.15 cycles on Ivy Bridge according to IACA.

This kind of sequences happen a lot on code using 32-bit indexes on 64-bit
architectures.

Note: The throughput numbers are similar on Sandy Bridge and Haswell.


** Proposed Solution **

To avoid the penalty of all these sign/zero extensions, we merge them in the
loads at the beginning of the chain of computation by promoting all the chain of
computation on the extended type. The promotion is done if and only if we do not
introduce new extensions, i.e., if we do not degrade the code quality.
To achieve this, we extend the existing “move ext to load” optimization with the
promotion mechanism introduced to match larger patterns for addressing mode
(r200947).
The idea of this extension is to perform the following transformation:
ext(promotableInst1(...(promotableInstN(load))))
=>
promotedInst1(...(promotedInstN(ext(load))))

The promotion mechanism in that optimization is enabled by a new TargetLowering
switch, which is off by default. In other words, by default, the optimization
performs the “move ext to load” optimization as it was before this patch.


** Performance **

Configuration: x86_64: Ivy Bridge fixed at 2900MHz running OS X 10.10.
Tested Optimization Levels: O3/Os
Tests: llvm-testsuite + externals.
Results:
- No regression beside noise.
- Improvements:
CINT2006/473.astar:  ~2%
Benchmarks/PAQ8p: ~2%
Misc/perlin: ~3%

The results are consistent for both O3 and Os.

<rdar://problem/18310086>

llvm-svn: 224402
2014-12-17 01:36:17 +00:00
Kevin Enderby
dc6f805541 Add printing the LC_ENCRYPTION_INFO_64 load command with llvm-objdump’s -private-headers
and add tests for the two AArch64 binaries.

llvm-svn: 224400
2014-12-17 01:01:30 +00:00
David Blaikie
93e50409ac PR21875: codegen for non-type template parameters of nullptr_t type
llvm-svn: 224399
2014-12-17 00:43:22 +00:00
Reid Kleckner
b4ee65bf9b Revert "[CodeGenPrepare] Move sign/zero extensions near loads using type promotion."
This reverts commit r224351. It causes assertion failures when building
ICU.

llvm-svn: 224397
2014-12-17 00:29:23 +00:00
Hans Wennborg
37a572f581 SelectionDAG switch lowering: use 'unsigned' to count destination popularity
SwitchInst::getNumCases() returns unsinged, so using uint64_t to count cases
seems unnecessary.

Also fix a missing CHECK in the test case.

llvm-svn: 224393
2014-12-16 23:41:59 +00:00
Colin LeMahieu
55e21b6e4f [Hexagon] Updating doubleword shift usages to new versions.
llvm-svn: 224391
2014-12-16 23:36:15 +00:00
Kevin Enderby
c4d55fc277 Add printing the LC_ENCRYPTION_INFO load command with llvm-objdump’s -private-headers.
llvm-svn: 224390
2014-12-16 23:25:52 +00:00
Duncan P. N. Exon Smith
4efb9deca4 Linker: Drop superseded subprograms
When a function gets replaced by `ModuleLinker`, drop superseded
subprograms.  This ensures that the "first" subprogram pointing at a
function is the same one that `!dbg` references point at.

This is a stop-gap fix for PR21910.  Notably, this fixes Release+Asserts
bootstraps that are currently asserting out in
`LexicalScopes::initialize()` due to the explicit instantiations in
`lib/IR/Dominators.cpp` eventually getting replaced by -argpromotion.

llvm-svn: 224389
2014-12-16 23:23:41 +00:00
Sanjay Patel
8f620fe4b0 fix typo, add spaces; NFC
llvm-svn: 224384
2014-12-16 22:48:42 +00:00
Simon Pilgrim
f9bdd6a092 [X86][SSE] Vector double -> float conversion memory folding (cvtpd2ps)
Added a missing memory folding relationship for the (V)CVTPD2PS instruction - we can safely fold these for stack reloads.

Differential Revision: http://reviews.llvm.org/D6663

llvm-svn: 224383
2014-12-16 22:30:10 +00:00
Sanjay Patel
af93d5f15c merge consecutive loads that are offset from a base address
SelectionDAG::isConsecutiveLoad() was not detecting consecutive loads
when the first load was offset from a base address. 

This patch recognizes that pattern and subtracts the offset before comparing
the second load to see if it is consecutive.

The codegen change in the new test case improves from:

vmovsd	32(%rdi), %xmm0
vmovsd	48(%rdi), %xmm1 
vmovhpd	56(%rdi), %xmm1, %xmm1
vmovhpd	40(%rdi), %xmm0, %xmm0
vinsertf128	$1, %xmm1, %ymm0, %ymm0

To:

vmovups	32(%rdi), %ymm0

An existing test case is also improved from:

vmovsd	(%rdi), %xmm0
vmovsd	16(%rdi), %xmm1
vmovsd	24(%rdi), %xmm2
vunpcklpd	%xmm2, %xmm0, %xmm0 ## xmm0 = xmm0[0],xmm2[0]
vmovhpd	8(%rdi), %xmm1, %xmm3

To:

vmovsd	(%rdi), %xmm0
vmovsd	16(%rdi), %xmm1
vmovhpd	24(%rdi), %xmm0, %xmm0
vmovhpd	8(%rdi), %xmm1, %xmm1

This patch fixes PR21771 ( http://llvm.org/bugs/show_bug.cgi?id=21771 ).

Differential Revision: http://reviews.llvm.org/D6642

llvm-svn: 224379
2014-12-16 21:57:18 +00:00
Kevin Enderby
601ffaa6fb Fix a bug in llvm-objdump’s -private-headers for the LC_VERSION_MIN_IPHONEOS
load command not getting printed.

llvm-svn: 224376
2014-12-16 21:48:27 +00:00
Colin LeMahieu
5cbdca29ae [Hexagon] Adding tstbit/bitclr/bitset instructions.
llvm-svn: 224374
2014-12-16 21:28:58 +00:00
Kostya Serebryany
7693e4617d [sanitizer] prevent function call merging for sanitizer-coverage callbacks
llvm-svn: 224372
2014-12-16 21:24:15 +00:00
Colin LeMahieu
bb5c698516 [Hexagon] Adding bit count and twiddling instructions.
llvm-svn: 224367
2014-12-16 20:57:56 +00:00
Colin LeMahieu
28f6e273c4 [Hexagon] Adding asr/lsr/asl reg/imm, asl with saturation, asr with rounding. Doubleword abs/neg/not. Interleave and deinterleave instructions.
llvm-svn: 224365
2014-12-16 20:40:23 +00:00
JF Bastien
02501293ba x86-32: PUSHF/POPF use/def EFLAGS
Summary: As a side-quest for D6629 jvoung pointed out that I should use -verify-machineinstrs and this found a bug in x86-32's handling of EFLAGS for PUSHF/POPF. This patch fixes the use/def, and adds -verify-machineinstrs to all x86 tests which contain 'EFLAGS'. One exception: this patch leaves inline-asm-fpstack.ll as-is because it fails -verify-machineinstrs in a way unrelated to EFLAGS. This patch also modifies cmpxchg-clobber-flags.ll along the lines of what D6629 already does by also testing i386.

Test Plan: ninja check

Reviewers: t.p.northover, jvoung

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6687

llvm-svn: 224359
2014-12-16 20:15:45 +00:00
Quentin Colombet
d31121348b [CodeGenPrepare] Move sign/zero extensions near loads using type promotion.
This patch extends the optimization in CodeGenPrepare that moves a sign/zero
extension near a load when the target can combine them. The optimization may
promote any operations between the extension and the load to make that possible.

Although this optimization may be beneficial for all targets, in particular
AArch64, this is enabled for X86 only as I have not benchmarked it for other
targets yet.


** Context **

Most targets feature extended loads, i.e., loads that perform a zero or sign
extension for free. In that context it is interesting to expose such pattern in
CodeGenPrepare so that the instruction selection pass can form such loads.
Sometimes, this pattern is blocked because of instructions between the load and
the extension. When those instructions are promotable to the extended type, we
can expose this pattern.


** Motivating Example **

Let us consider an example:
define void @foo(i8* %addr1, i32* %addr2, i8 %a, i32 %b) {
  %ld = load i8* %addr1
  %zextld = zext i8 %ld to i32
  %ld2 = load i32* %addr2
  %add = add nsw i32 %ld2, %zextld
  %sextadd = sext i32 %add to i64
  %zexta = zext i8 %a to i32
  %addza = add nsw i32 %zexta, %zextld
  %sextaddza = sext i32 %addza to i64
  %addb = add nsw i32 %b, %zextld
  %sextaddb = sext i32 %addb to i64
  call void @dummy(i64 %sextadd, i64 %sextaddza, i64 %sextaddb)
  ret void
}

As it is, this IR generates the following assembly on x86_64:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movl  (%rsi), %es      # plain load
  addl  %eax, %esi       # 32-bit add
  movslq  %esi, %rdi     # sign extend the result of add
  movzbl  %dl, %edx      # zero extend the first argument
  addl  %eax, %edx       # 32-bit add
  movslq  %edx, %rsi     # sign extend the result of add
  addl  %eax, %ecx       # 32-bit add
  movslq  %ecx, %rdx     # sign extend the result of add
[...]
The throughput of this sequence is 7.45 cycles on Ivy Bridge according to IACA.

Now, by promoting the additions to form more extended loads we would generate:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movslq  (%rsi), %rdi   # sign-extended load
  addq  %rax, %rdi       # 64-bit add
  movzbl  %dl, %esi      # zero extend the first argument
  addq  %rax, %rsi       # 64-bit add
  movslq  %ecx, %rdx     # sign extend the second argument
  addq  %rax, %rdx       # 64-bit add
[...]
The throughput of this sequence is 6.15 cycles on Ivy Bridge according to IACA.

This kind of sequences happen a lot on code using 32-bit indexes on 64-bit
architectures.

Note: The throughput numbers are similar on Sandy Bridge and Haswell.


** Proposed Solution **

To avoid the penalty of all these sign/zero extensions, we merge them in the
loads at the beginning of the chain of computation by promoting all the chain of
computation on the extended type. The promotion is done if and only if we do not
introduce new extensions, i.e., if we do not degrade the code quality.
To achieve this, we extend the existing “move ext to load” optimization with the
promotion mechanism introduced to match larger patterns for addressing mode
(r200947).
The idea of this extension is to perform the following transformation:
ext(promotableInst1(...(promotableInstN(load))))
=>
promotedInst1(...(promotedInstN(ext(load))))

The promotion mechanism in that optimization is enabled by a new TargetLowering
switch, which is off by default. In other words, by default, the optimization
performs the “move ext to load” optimization as it was before this patch.


** Performance **

Configuration: x86_64: Ivy Bridge fixed at 2900MHz running OS X 10.10.
Tested Optimization Levels: O3/Os
Tests: llvm-testsuite + externals.
Results:
- No regression beside noise.
- Improvements:
CINT2006/473.astar:  ~2%
Benchmarks/PAQ8p: ~2%
Misc/perlin: ~3%

The results are consistent for both O3 and Os.

<rdar://problem/18310086>

llvm-svn: 224351
2014-12-16 19:09:03 +00:00