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[NFC][InstCombine] More test for "sign bit test via shifts" pattern (PR43595)

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While that pattern is indirectly handled via
reassociateShiftAmtsOfTwoSameDirectionShifts(),
that incursme one-use restriction on truncation,
which is pointless since we know that we'll produce a single instruction.

Additionally, *if* we are only looking for sign bit,
we don't need shifts to be identical,
which isn't the case in general,
and is the blocker for me in bug in question:

https://bugs.llvm.org/show_bug.cgi?id=43595

llvm-svn: 374726
This commit is contained in:
Roman Lebedev 2019-10-13 17:11:16 +00:00
parent 8773c2f418
commit 5dbe65e8a0
6 changed files with 377 additions and 13 deletions
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8
test/Transforms/InstCombine/shift-amount-reassociation-in-bittest.ll
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@ -671,6 +671,14 @@ define <2 x i1> @n38_overshift(<2 x i32> %x, <2 x i32> %y) {
; As usual, don't crash given constantexpr's :/
@f.a = internal global i16 0
define i1 @constantexpr() {
; CHECK-LABEL: @constantexpr(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = load i16, i16* @f.a, align 2
; CHECK-NEXT: [[TMP1:%.*]] = lshr i16 [[TMP0]], 1
; CHECK-NEXT: [[TMP2:%.*]] = and i16 [[TMP1]], shl (i16 1, i16 zext (i1 icmp ne (i16 ptrtoint (i16* @f.a to i16), i16 1) to i16))
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i16 [[TMP2]], 0
; CHECK-NEXT: ret i1 [[TOBOOL]]
;
entry:
%0 = load i16, i16* @f.a
%shr = ashr i16 %0, 1

26
test/Transforms/InstCombine/shift-amount-reassociation-with-truncation-ashr.ll
View File

@ -166,7 +166,9 @@ define i16 @t9_ashr(i32 %x, i16 %y) {
; CHECK-NEXT: [[T1:%.*]] = zext i16 [[T0]] to i32
; CHECK-NEXT: [[T2:%.*]] = ashr i32 [[X:%.*]], [[T1]]
; CHECK-NEXT: [[T3:%.*]] = trunc i32 [[T2]] to i16
; CHECK-NEXT: ret i16 [[T3]]
; CHECK-NEXT: [[T4:%.*]] = add i16 [[Y]], -2
; CHECK-NEXT: [[T5:%.*]] = ashr i16 [[T3]], [[T4]]
; CHECK-NEXT: ret i16 [[T5]]
;
%t0 = sub i16 32, %y
%t1 = zext i16 %t0 to i32
@ -174,5 +176,25 @@ define i16 @t9_ashr(i32 %x, i16 %y) {
%t3 = trunc i32 %t2 to i16
%t4 = add i16 %y, -2
%t5 = ashr i16 %t3, %t4
ret i16 %t3
ret i16 %t5
}
; If we have different right-shifts, in general, we can't do anything with it.
define i16 @n10_lshr_ashr(i32 %x, i16 %y) {
; CHECK-LABEL: @n10_lshr_ashr(
; CHECK-NEXT: [[T0:%.*]] = sub i16 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = zext i16 [[T0]] to i32
; CHECK-NEXT: [[T2:%.*]] = lshr i32 [[X:%.*]], [[T1]]
; CHECK-NEXT: [[T3:%.*]] = trunc i32 [[T2]] to i16
; CHECK-NEXT: [[T4:%.*]] = add i16 [[Y]], -1
; CHECK-NEXT: [[T5:%.*]] = ashr i16 [[T3]], [[T4]]
; CHECK-NEXT: ret i16 [[T5]]
;
%t0 = sub i16 32, %y
%t1 = zext i16 %t0 to i32
%t2 = lshr i32 %x, %t1
%t3 = trunc i32 %t2 to i16
%t4 = add i16 %y, -1
%t5 = ashr i16 %t3, %t4
ret i16 %t5
}

26
test/Transforms/InstCombine/shift-amount-reassociation-with-truncation-lshr.ll
View File

@ -166,7 +166,9 @@ define i16 @t9_lshr(i32 %x, i16 %y) {
; CHECK-NEXT: [[T1:%.*]] = zext i16 [[T0]] to i32
; CHECK-NEXT: [[T2:%.*]] = lshr i32 [[X:%.*]], [[T1]]
; CHECK-NEXT: [[T3:%.*]] = trunc i32 [[T2]] to i16
; CHECK-NEXT: ret i16 [[T3]]
; CHECK-NEXT: [[T4:%.*]] = add i16 [[Y]], -2
; CHECK-NEXT: [[T5:%.*]] = lshr i16 [[T3]], [[T4]]
; CHECK-NEXT: ret i16 [[T5]]
;
%t0 = sub i16 32, %y
%t1 = zext i16 %t0 to i32
@ -174,5 +176,25 @@ define i16 @t9_lshr(i32 %x, i16 %y) {
%t3 = trunc i32 %t2 to i16
%t4 = add i16 %y, -2
%t5 = lshr i16 %t3, %t4
ret i16 %t3
ret i16 %t5
}
; If we have different right-shifts, in general, we can't do anything with it.
define i16 @n10_ashr_lshr(i32 %x, i16 %y) {
; CHECK-LABEL: @n10_ashr_lshr(
; CHECK-NEXT: [[T0:%.*]] = sub i16 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = zext i16 [[T0]] to i32
; CHECK-NEXT: [[T2:%.*]] = ashr i32 [[X:%.*]], [[T1]]
; CHECK-NEXT: [[T3:%.*]] = trunc i32 [[T2]] to i16
; CHECK-NEXT: [[T4:%.*]] = add i16 [[Y]], -1
; CHECK-NEXT: [[T5:%.*]] = lshr i16 [[T3]], [[T4]]
; CHECK-NEXT: ret i16 [[T5]]
;
%t0 = sub i16 32, %y
%t1 = zext i16 %t0 to i32
%t2 = ashr i32 %x, %t1
%t3 = trunc i32 %t2 to i16
%t4 = add i16 %y, -1
%t5 = lshr i16 %t3, %t4
ret i16 %t5
}

8
test/Transforms/InstCombine/shift-amount-reassociation-with-truncation-shl.ll
View File

@ -181,15 +181,17 @@ define i16 @n11(i32 %x, i16 %y) {
; CHECK-NEXT: [[T1:%.*]] = zext i16 [[T0]] to i32
; CHECK-NEXT: [[T2:%.*]] = shl i32 [[X:%.*]], [[T1]]
; CHECK-NEXT: [[T3:%.*]] = trunc i32 [[T2]] to i16
; CHECK-NEXT: ret i16 [[T3]]
; CHECK-NEXT: [[T4:%.*]] = add i16 [[Y]], -31
; CHECK-NEXT: [[T5:%.*]] = shl i16 [[T3]], [[T4]]
; CHECK-NEXT: ret i16 [[T5]]
;
%t0 = sub i16 30, %y
%t1 = zext i16 %t0 to i32
%t2 = shl i32 %x, %t1
%t3 = trunc i32 %t2 to i16
%t4 = add i16 %y, -24
%t4 = add i16 %y, -31
%t5 = shl i16 %t3, %t4
ret i16 %t3
ret i16 %t5
}
; Bit width mismatch of shit amount

116
test/Transforms/InstCombine/shift-amount-reassociation.ll
View File

@ -203,3 +203,119 @@ define <2 x i32> @t13_vec(<2 x i32> %x, <2 x i32> %y) {
%t3 = lshr <2 x i32> %t1, %t2
ret <2 x i32> %t3
}
; If we have different right-shifts, in general, we can't do anything with it.
define i32 @n13(i32 %x, i32 %y) {
; CHECK-LABEL: @n13(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = lshr i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -2
; CHECK-NEXT: [[T3:%.*]] = ashr i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = lshr i32 %x, %t0
%t2 = add i32 %y, -2
%t3 = ashr i32 %t1, %t2
ret i32 %t3
}
define i32 @n14(i32 %x, i32 %y) {
; CHECK-LABEL: @n14(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = lshr i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -1
; CHECK-NEXT: [[T3:%.*]] = ashr i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = lshr i32 %x, %t0
%t2 = add i32 %y, -1
%t3 = ashr i32 %t1, %t2
ret i32 %t3
}
define i32 @n15(i32 %x, i32 %y) {
; CHECK-LABEL: @n15(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = ashr i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -2
; CHECK-NEXT: [[T3:%.*]] = lshr i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = ashr i32 %x, %t0
%t2 = add i32 %y, -2
%t3 = lshr i32 %t1, %t2
ret i32 %t3
}
define i32 @n16(i32 %x, i32 %y) {
; CHECK-LABEL: @n16(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = ashr i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -1
; CHECK-NEXT: [[T3:%.*]] = lshr i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = ashr i32 %x, %t0
%t2 = add i32 %y, -1
%t3 = lshr i32 %t1, %t2
ret i32 %t3
}
; If the shift direction is different, then this should be handled elsewhere.
define i32 @n17(i32 %x, i32 %y) {
; CHECK-LABEL: @n17(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = shl i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -1
; CHECK-NEXT: [[T3:%.*]] = lshr i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = shl i32 %x, %t0
%t2 = add i32 %y, -1
%t3 = lshr i32 %t1, %t2
ret i32 %t3
}
define i32 @n18(i32 %x, i32 %y) {
; CHECK-LABEL: @n18(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = shl i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -1
; CHECK-NEXT: [[T3:%.*]] = ashr i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = shl i32 %x, %t0
%t2 = add i32 %y, -1
%t3 = ashr i32 %t1, %t2
ret i32 %t3
}
define i32 @n19(i32 %x, i32 %y) {
; CHECK-LABEL: @n19(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = lshr i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -1
; CHECK-NEXT: [[T3:%.*]] = shl i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = lshr i32 %x, %t0
%t2 = add i32 %y, -1
%t3 = shl i32 %t1, %t2
ret i32 %t3
}
define i32 @n20(i32 %x, i32 %y) {
; CHECK-LABEL: @n20(
; CHECK-NEXT: [[T0:%.*]] = sub i32 32, [[Y:%.*]]
; CHECK-NEXT: [[T1:%.*]] = ashr i32 [[X:%.*]], [[T0]]
; CHECK-NEXT: [[T2:%.*]] = add i32 [[Y]], -1
; CHECK-NEXT: [[T3:%.*]] = shl i32 [[T1]], [[T2]]
; CHECK-NEXT: ret i32 [[T3]]
;
%t0 = sub i32 32, %y
%t1 = ashr i32 %x, %t0
%t2 = add i32 %y, -1
%t3 = shl i32 %t1, %t2
ret i32 %t3
}

206
test/Transforms/InstCombine/sign-bit-test-via-right-shifting-all-other-bits.ll
View File

@ -1,22 +1,51 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
declare void @use32(i32)
declare void @use64(i64)
define i1 @highest_bit_test_via_lshr(i32 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_lshr(
; CHECK-NEXT: [[ISNEG:%.*]] = icmp slt i32 [[DATA:%.*]], 0
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 32, [[NBITS:%.*]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = lshr i32 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP]]
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = lshr i32 [[DATA]], 31
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp slt i32 [[DATA]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 32, %nbits
%high_bits_extracted = lshr i32 %data, %num_low_bits_to_skip
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = lshr i32 %high_bits_extracted, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use32(i32 %high_bits_extracted)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
define i1 @highest_bit_test_via_lshr_with_truncation(i64 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_lshr_with_truncation(
; CHECK-NEXT: [[ISNEG:%.*]] = icmp slt i64 [[DATA:%.*]], 0
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 64, [[NBITS:%.*]]
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP_WIDE:%.*]] = zext i32 [[NUM_LOW_BITS_TO_SKIP]] to i64
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP_WIDE]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED_NARROW:%.*]] = trunc i64 [[HIGH_BITS_EXTRACTED]] to i32
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = lshr i32 [[HIGH_BITS_EXTRACTED_NARROW]], [[SKIP_ALL_BITS_TILL_SIGNBIT]]
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use64(i64 [[NUM_LOW_BITS_TO_SKIP_WIDE]])
; CHECK-NEXT: call void @use64(i64 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED_NARROW]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp ne i32 [[SIGNBIT]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 64, %nbits
@ -25,26 +54,60 @@ define i1 @highest_bit_test_via_lshr_with_truncation(i64 %data, i32 %nbits) {
%high_bits_extracted_narrow = trunc i64 %high_bits_extracted to i32
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = lshr i32 %high_bits_extracted_narrow, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use64(i64 %num_low_bits_to_skip_wide)
call void @use64(i64 %high_bits_extracted)
call void @use32(i32 %high_bits_extracted_narrow)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
define i1 @highest_bit_test_via_ashr(i32 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_ashr(
; CHECK-NEXT: [[ISNEG:%.*]] = icmp slt i32 [[DATA:%.*]], 0
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 32, [[NBITS:%.*]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = ashr i32 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP]]
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = ashr i32 [[DATA]], 31
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp slt i32 [[DATA]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 32, %nbits
%high_bits_extracted = ashr i32 %data, %num_low_bits_to_skip
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = ashr i32 %high_bits_extracted, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use32(i32 %high_bits_extracted)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
define i1 @highest_bit_test_via_ashr_with_truncation(i64 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_ashr_with_truncation(
; CHECK-NEXT: [[ISNEG:%.*]] = icmp slt i64 [[DATA:%.*]], 0
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 64, [[NBITS:%.*]]
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP_WIDE:%.*]] = zext i32 [[NUM_LOW_BITS_TO_SKIP]] to i64
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = ashr i64 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP_WIDE]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED_NARROW:%.*]] = trunc i64 [[HIGH_BITS_EXTRACTED]] to i32
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = ashr i32 [[HIGH_BITS_EXTRACTED_NARROW]], [[SKIP_ALL_BITS_TILL_SIGNBIT]]
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use64(i64 [[NUM_LOW_BITS_TO_SKIP_WIDE]])
; CHECK-NEXT: call void @use64(i64 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED_NARROW]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp ne i32 [[SIGNBIT]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 64, %nbits
@ -53,12 +116,143 @@ define i1 @highest_bit_test_via_ashr_with_truncation(i64 %data, i32 %nbits) {
%high_bits_extracted_narrow = trunc i64 %high_bits_extracted to i32
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = ashr i32 %high_bits_extracted_narrow, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use64(i64 %num_low_bits_to_skip_wide)
call void @use64(i64 %high_bits_extracted)
call void @use32(i32 %high_bits_extracted_narrow)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
declare void @use32(i32)
declare void @use64(i64)
define i1 @highest_bit_test_via_lshr_ashr(i32 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_lshr_ashr(
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 32, [[NBITS:%.*]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = lshr i32 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP]]
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = ashr i32 [[HIGH_BITS_EXTRACTED]], [[SKIP_ALL_BITS_TILL_SIGNBIT]]
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp ne i32 [[SIGNBIT]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 32, %nbits
%high_bits_extracted = lshr i32 %data, %num_low_bits_to_skip
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = ashr i32 %high_bits_extracted, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use32(i32 %high_bits_extracted)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
define i1 @highest_bit_test_via_lshr_ashe_with_truncation(i64 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_lshr_ashe_with_truncation(
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 64, [[NBITS:%.*]]
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP_WIDE:%.*]] = zext i32 [[NUM_LOW_BITS_TO_SKIP]] to i64
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP_WIDE]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED_NARROW:%.*]] = trunc i64 [[HIGH_BITS_EXTRACTED]] to i32
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = ashr i32 [[HIGH_BITS_EXTRACTED_NARROW]], [[SKIP_ALL_BITS_TILL_SIGNBIT]]
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use64(i64 [[NUM_LOW_BITS_TO_SKIP_WIDE]])
; CHECK-NEXT: call void @use64(i64 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED_NARROW]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp ne i32 [[SIGNBIT]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 64, %nbits
%num_low_bits_to_skip_wide = zext i32 %num_low_bits_to_skip to i64
%high_bits_extracted = lshr i64 %data, %num_low_bits_to_skip_wide
%high_bits_extracted_narrow = trunc i64 %high_bits_extracted to i32
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = ashr i32 %high_bits_extracted_narrow, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use64(i64 %num_low_bits_to_skip_wide)
call void @use64(i64 %high_bits_extracted)
call void @use32(i32 %high_bits_extracted_narrow)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
define i1 @highest_bit_test_via_ashr_lshr(i32 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_ashr_lshr(
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 32, [[NBITS:%.*]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = ashr i32 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP]]
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = lshr i32 [[HIGH_BITS_EXTRACTED]], [[SKIP_ALL_BITS_TILL_SIGNBIT]]
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp ne i32 [[SIGNBIT]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 32, %nbits
%high_bits_extracted = ashr i32 %data, %num_low_bits_to_skip
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = lshr i32 %high_bits_extracted, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use32(i32 %high_bits_extracted)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
define i1 @highest_bit_test_via_ashr_lshr_with_truncation(i64 %data, i32 %nbits) {
; CHECK-LABEL: @highest_bit_test_via_ashr_lshr_with_truncation(
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP:%.*]] = sub i32 64, [[NBITS:%.*]]
; CHECK-NEXT: [[NUM_LOW_BITS_TO_SKIP_WIDE:%.*]] = zext i32 [[NUM_LOW_BITS_TO_SKIP]] to i64
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED:%.*]] = ashr i64 [[DATA:%.*]], [[NUM_LOW_BITS_TO_SKIP_WIDE]]
; CHECK-NEXT: [[HIGH_BITS_EXTRACTED_NARROW:%.*]] = trunc i64 [[HIGH_BITS_EXTRACTED]] to i32
; CHECK-NEXT: [[SKIP_ALL_BITS_TILL_SIGNBIT:%.*]] = add i32 [[NBITS]], -1
; CHECK-NEXT: [[SIGNBIT:%.*]] = lshr i32 [[HIGH_BITS_EXTRACTED_NARROW]], [[SKIP_ALL_BITS_TILL_SIGNBIT]]
; CHECK-NEXT: call void @use32(i32 [[NUM_LOW_BITS_TO_SKIP]])
; CHECK-NEXT: call void @use64(i64 [[NUM_LOW_BITS_TO_SKIP_WIDE]])
; CHECK-NEXT: call void @use64(i64 [[HIGH_BITS_EXTRACTED]])
; CHECK-NEXT: call void @use32(i32 [[HIGH_BITS_EXTRACTED_NARROW]])
; CHECK-NEXT: call void @use32(i32 [[SKIP_ALL_BITS_TILL_SIGNBIT]])
; CHECK-NEXT: call void @use32(i32 [[SIGNBIT]])
; CHECK-NEXT: [[ISNEG:%.*]] = icmp ne i32 [[SIGNBIT]], 0
; CHECK-NEXT: ret i1 [[ISNEG]]
;
%num_low_bits_to_skip = sub i32 64, %nbits
%num_low_bits_to_skip_wide = zext i32 %num_low_bits_to_skip to i64
%high_bits_extracted = ashr i64 %data, %num_low_bits_to_skip_wide
%high_bits_extracted_narrow = trunc i64 %high_bits_extracted to i32
%skip_all_bits_till_signbit = sub i32 %nbits, 1
%signbit = lshr i32 %high_bits_extracted_narrow, %skip_all_bits_till_signbit
call void @use32(i32 %num_low_bits_to_skip)
call void @use64(i64 %num_low_bits_to_skip_wide)
call void @use64(i64 %high_bits_extracted)
call void @use32(i32 %high_bits_extracted_narrow)
call void @use32(i32 %skip_all_bits_till_signbit)
call void @use32(i32 %signbit)
%isneg = icmp ne i32 %signbit, 0
ret i1 %isneg
}
;------------------------------------------------------------------------------;
define i1 @unsigned_sign_bit_extract(i32 %x) {
; CHECK-LABEL: @unsigned_sign_bit_extract(