llvm-project/llvm/test/Transforms/InstCombine/zext.ll

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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
define i64 @test_sext_zext(i16 %A) {
; CHECK-LABEL: @test_sext_zext(
; CHECK-NEXT: [[C2:%.*]] = zext i16 [[A:%.*]] to i64
; CHECK-NEXT: ret i64 [[C2]]
;
%c1 = zext i16 %A to i32
%c2 = sext i32 %c1 to i64
ret i64 %c2
}
define <2 x i64> @test2(<2 x i1> %A) {
; CHECK-LABEL: @test2(
; CHECK-NEXT: [[XOR:%.*]] = xor <2 x i1> [[A:%.*]], <i1 true, i1 true>
; CHECK-NEXT: [[ZEXT:%.*]] = zext <2 x i1> [[XOR]] to <2 x i64>
; CHECK-NEXT: ret <2 x i64> [[ZEXT]]
;
%xor = xor <2 x i1> %A, <i1 true, i1 true>
%zext = zext <2 x i1> %xor to <2 x i64>
ret <2 x i64> %zext
}
define <2 x i64> @test3(<2 x i64> %A) {
; CHECK-LABEL: @test3(
; CHECK-NEXT: [[ZEXT:%.*]] = and <2 x i64> [[A:%.*]], <i64 23, i64 42>
; CHECK-NEXT: ret <2 x i64> [[ZEXT]]
;
%trunc = trunc <2 x i64> %A to <2 x i32>
%and = and <2 x i32> %trunc, <i32 23, i32 42>
%zext = zext <2 x i32> %and to <2 x i64>
ret <2 x i64> %zext
}
define <2 x i64> @test4(<2 x i64> %A) {
; CHECK-LABEL: @test4(
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i64> [[A:%.*]], <i64 23, i64 42>
; CHECK-NEXT: [[ZEXT:%.*]] = xor <2 x i64> [[TMP1]], <i64 23, i64 42>
; CHECK-NEXT: ret <2 x i64> [[ZEXT]]
;
%trunc = trunc <2 x i64> %A to <2 x i32>
%and = and <2 x i32> %trunc, <i32 23, i32 42>
%xor = xor <2 x i32> %and, <i32 23, i32 42>
%zext = zext <2 x i32> %xor to <2 x i64>
ret <2 x i64> %zext
}
define i64 @fold_xor_zext_sandwich(i1 %a) {
; CHECK-LABEL: @fold_xor_zext_sandwich(
; CHECK-NEXT: [[TMP1:%.*]] = xor i1 [[A:%.*]], true
; CHECK-NEXT: [[ZEXT2:%.*]] = zext i1 [[TMP1]] to i64
; CHECK-NEXT: ret i64 [[ZEXT2]]
;
%zext1 = zext i1 %a to i32
%xor = xor i32 %zext1, 1
%zext2 = zext i32 %xor to i64
ret i64 %zext2
}
define <2 x i64> @fold_xor_zext_sandwich_vec(<2 x i1> %a) {
; CHECK-LABEL: @fold_xor_zext_sandwich_vec(
; CHECK-NEXT: [[TMP1:%.*]] = xor <2 x i1> [[A:%.*]], <i1 true, i1 true>
; CHECK-NEXT: [[ZEXT2:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i64>
; CHECK-NEXT: ret <2 x i64> [[ZEXT2]]
;
%zext1 = zext <2 x i1> %a to <2 x i32>
%xor = xor <2 x i32> %zext1, <i32 1, i32 1>
%zext2 = zext <2 x i32> %xor to <2 x i64>
ret <2 x i64> %zext2
}
; Assert that zexts in and(zext(icmp), zext(icmp)) can be folded.
define i8 @fold_and_zext_icmp(i64 %a, i64 %b, i64 %c) {
; CHECK-LABEL: @fold_and_zext_icmp(
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i64 [[A]], [[C:%.*]]
; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i8
; CHECK-NEXT: ret i8 [[TMP4]]
;
%1 = icmp sgt i64 %a, %b
%2 = zext i1 %1 to i8
%3 = icmp slt i64 %a, %c
%4 = zext i1 %3 to i8
%5 = and i8 %2, %4
ret i8 %5
}
; Assert that zexts in or(zext(icmp), zext(icmp)) can be folded.
define i8 @fold_or_zext_icmp(i64 %a, i64 %b, i64 %c) {
; CHECK-LABEL: @fold_or_zext_icmp(
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i64 [[A]], [[C:%.*]]
; CHECK-NEXT: [[TMP3:%.*]] = or i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i8
; CHECK-NEXT: ret i8 [[TMP4]]
;
%1 = icmp sgt i64 %a, %b
%2 = zext i1 %1 to i8
%3 = icmp slt i64 %a, %c
%4 = zext i1 %3 to i8
%5 = or i8 %2, %4
ret i8 %5
}
; Assert that zexts in xor(zext(icmp), zext(icmp)) can be folded.
define i8 @fold_xor_zext_icmp(i64 %a, i64 %b, i64 %c) {
; CHECK-LABEL: @fold_xor_zext_icmp(
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i64 [[A]], [[C:%.*]]
; CHECK-NEXT: [[TMP3:%.*]] = xor i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: [[TMP4:%.*]] = zext i1 [[TMP3]] to i8
; CHECK-NEXT: ret i8 [[TMP4]]
;
%1 = icmp sgt i64 %a, %b
%2 = zext i1 %1 to i8
%3 = icmp slt i64 %a, %c
%4 = zext i1 %3 to i8
%5 = xor i8 %2, %4
ret i8 %5
}
; Assert that zexts in logic(zext(icmp), zext(icmp)) are also folded accross
; nested logical operators.
define i8 @fold_nested_logic_zext_icmp(i64 %a, i64 %b, i64 %c, i64 %d) {
; CHECK-LABEL: @fold_nested_logic_zext_icmp(
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i64 [[A]], [[C:%.*]]
; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i64 [[A]], [[D:%.*]]
; CHECK-NEXT: [[TMP5:%.*]] = or i1 [[TMP3]], [[TMP4]]
; CHECK-NEXT: [[TMP6:%.*]] = zext i1 [[TMP5]] to i8
; CHECK-NEXT: ret i8 [[TMP6]]
;
%1 = icmp sgt i64 %a, %b
%2 = zext i1 %1 to i8
%3 = icmp slt i64 %a, %c
%4 = zext i1 %3 to i8
%5 = and i8 %2, %4
%6 = icmp eq i64 %a, %d
%7 = zext i1 %6 to i8
%8 = or i8 %5, %7
ret i8 %8
}
; This test is for Integer BitWidth > 64 && BitWidth <= 1024.
define i1024 @sext_zext_apint1(i77 %A) {
; CHECK-LABEL: @sext_zext_apint1(
; CHECK-NEXT: [[C2:%.*]] = zext i77 [[A:%.*]] to i1024
; CHECK-NEXT: ret i1024 [[C2]]
;
%c1 = zext i77 %A to i533
%c2 = sext i533 %c1 to i1024
ret i1024 %c2
}
; This test is for Integer BitWidth <= 64 && BitWidth % 2 != 0.
define i47 @sext_zext_apint2(i11 %A) {
; CHECK-LABEL: @sext_zext_apint2(
; CHECK-NEXT: [[C2:%.*]] = zext i11 [[A:%.*]] to i47
; CHECK-NEXT: ret i47 [[C2]]
;
%c1 = zext i11 %A to i39
%c2 = sext i39 %c1 to i47
ret i47 %c2
}
declare void @use1(i1)
declare void @use32(i32)
define i32 @masked_bit_set(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_set(
; CHECK-NEXT: [[TMP1:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP1]], 1
; CHECK-NEXT: ret i32 [[TMP2]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
%cmp = icmp ne i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
define <2 x i32> @masked_bit_clear(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: @masked_bit_clear(
; CHECK-NEXT: [[TMP1:%.*]] = xor <2 x i32> [[X:%.*]], <i32 -1, i32 -1>
; CHECK-NEXT: [[TMP2:%.*]] = lshr <2 x i32> [[TMP1]], [[Y:%.*]]
; CHECK-NEXT: [[TMP3:%.*]] = and <2 x i32> [[TMP2]], <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i32> [[TMP3]]
;
%sh1 = shl <2 x i32> <i32 1, i32 1>, %y
%and = and <2 x i32> %sh1, %x
%cmp = icmp eq <2 x i32> %and, zeroinitializer
%r = zext <2 x i1> %cmp to <2 x i32>
ret <2 x i32> %r
}
define <2 x i32> @masked_bit_set_commute(<2 x i32> %px, <2 x i32> %y) {
; CHECK-LABEL: @masked_bit_set_commute(
; CHECK-NEXT: [[X:%.*]] = srem <2 x i32> <i32 42, i32 3>, [[PX:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = lshr <2 x i32> [[X]], [[Y:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = and <2 x i32> [[TMP1]], <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i32> [[TMP2]]
;
%x = srem <2 x i32> <i32 42, i32 3>, %px ; thwart complexity-based canonicalization
%sh1 = shl <2 x i32> <i32 1, i32 1>, %y
%and = and <2 x i32> %x, %sh1
%cmp = icmp ne <2 x i32> %and, zeroinitializer
%r = zext <2 x i1> %cmp to <2 x i32>
ret <2 x i32> %r
}
define i32 @masked_bit_clear_commute(i32 %px, i32 %y) {
; CHECK-LABEL: @masked_bit_clear_commute(
; CHECK-NEXT: [[X:%.*]] = srem i32 42, [[PX:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X]], -1
; CHECK-NEXT: [[TMP2:%.*]] = lshr i32 [[TMP1]], [[Y:%.*]]
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP2]], 1
; CHECK-NEXT: ret i32 [[TMP3]]
;
%x = srem i32 42, %px ; thwart complexity-based canonicalization
%sh1 = shl i32 1, %y
%and = and i32 %x, %sh1
%cmp = icmp eq i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
define i32 @masked_bit_set_use1(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_set_use1(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: call void @use32(i32 [[SH1]])
; CHECK-NEXT: [[TMP1:%.*]] = lshr i32 [[X:%.*]], [[Y]]
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP1]], 1
; CHECK-NEXT: ret i32 [[TMP2]]
;
%sh1 = shl i32 1, %y
call void @use32(i32 %sh1)
%and = and i32 %sh1, %x
%cmp = icmp ne i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bit_set_use2(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_set_use2(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: call void @use32(i32 [[AND]])
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], 0
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
call void @use32(i32 %and)
%cmp = icmp ne i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bit_set_use3(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_set_use3(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], 0
; CHECK-NEXT: call void @use1(i1 [[CMP]])
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
%cmp = icmp ne i32 %and, 0
call void @use1(i1 %cmp)
%r = zext i1 %cmp to i32
ret i32 %r
}
define i32 @masked_bit_clear_use1(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_clear_use1(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: call void @use32(i32 [[SH1]])
; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[X:%.*]], -1
; CHECK-NEXT: [[TMP2:%.*]] = lshr i32 [[TMP1]], [[Y]]
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP2]], 1
; CHECK-NEXT: ret i32 [[TMP3]]
;
%sh1 = shl i32 1, %y
call void @use32(i32 %sh1)
%and = and i32 %sh1, %x
%cmp = icmp eq i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bit_clear_use2(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_clear_use2(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: call void @use32(i32 [[AND]])
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], 0
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
call void @use32(i32 %and)
%cmp = icmp eq i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bit_clear_use3(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_clear_use3(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], 0
; CHECK-NEXT: call void @use1(i1 [[CMP]])
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
%cmp = icmp eq i32 %and, 0
call void @use1(i1 %cmp)
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bits_set(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bits_set(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 3, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], 0
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 3, %y
%and = and i32 %sh1, %x
%cmp = icmp ne i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @div_bit_set(i32 %x, i32 %y) {
; CHECK-LABEL: @div_bit_set(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = sdiv i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], 0
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = sdiv i32 %sh1, %x
%cmp = icmp ne i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bit_set_nonzero_cmp(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_set_nonzero_cmp(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], 1
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
%cmp = icmp ne i32 %and, 1
%r = zext i1 %cmp to i32
ret i32 %r
}
; Negative test
define i32 @masked_bit_wrong_pred(i32 %x, i32 %y) {
; CHECK-LABEL: @masked_bit_wrong_pred(
; CHECK-NEXT: [[SH1:%.*]] = shl i32 1, [[Y:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SH1]], [[X:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[AND]], 0
; CHECK-NEXT: [[R:%.*]] = zext i1 [[CMP]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%sh1 = shl i32 1, %y
%and = and i32 %sh1, %x
%cmp = icmp sgt i32 %and, 0
%r = zext i1 %cmp to i32
ret i32 %r
}
define i32 @zext_or_masked_bit_test(i32 %a, i32 %b, i32 %x) {
; CHECK-LABEL: @zext_or_masked_bit_test(
[InstCombine] remove a buggy set of zext-icmp transforms The motivating case is an infinite loop shown with a reduced test from: https://llvm.org/PR51762 To solve this, I'm proposing we delete the most obviously broken part of this code. The bug example shows a fundamental problem: we ask computeKnownBits if a transform will be profitable, alter the code by creating new instructions, then rely on computeKnownBits to return the same answer to actually eliminate instructions. But there's no guarantee that the results will be the same between the 1st and 2nd calls. In the infinite loop example, we get different answers, so we add instructions that conflict with some other transform, and we're stuck. There's at least one other problem visible in the test diff for `@zext_or_masked_bit_test_uses`: the code doesn't check uses properly, so we can end up with extra instructions created. Last, it's not clear if this set of transforms actually improves analysis or codegen. I spot-checked a few targets and don't see a clear win: https://godbolt.org/z/x87EWovso If we do see a regression from this change, codegen seems like the right place to add a cmp -> bit-hack fold. If this is too big of a step, we could limit the computeKnownBits calls by not passing a context instruction and/or limiting the recursion. I checked that those would stop the infinite loop for PR51762, but that won't guarantee that some other example does not fall into the same loop. Differential Revision: https://reviews.llvm.org/D109440
2021-09-09 20:45:56 +08:00
; CHECK-NEXT: [[SHL:%.*]] = shl i32 1, [[B:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SHL]], [[A:%.*]]
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[AND]], 0
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[X:%.*]], [[B]]
; CHECK-NEXT: [[OR:%.*]] = or i1 [[TOBOOL]], [[CMP]]
; CHECK-NEXT: [[Z:%.*]] = zext i1 [[OR]] to i32
; CHECK-NEXT: ret i32 [[Z]]
;
%shl = shl i32 1, %b
%and = and i32 %shl, %a
%tobool = icmp ne i32 %and, 0
%cmp = icmp eq i32 %x, %b
%or = or i1 %tobool, %cmp
%z = zext i1 %or to i32
ret i32 %z
}
define i32 @zext_or_masked_bit_test_uses(i32 %a, i32 %b, i32 %x) {
; CHECK-LABEL: @zext_or_masked_bit_test_uses(
; CHECK-NEXT: [[SHL:%.*]] = shl i32 1, [[B:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[SHL]], [[A:%.*]]
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[AND]], 0
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[X:%.*]], [[B]]
; CHECK-NEXT: [[OR:%.*]] = or i1 [[TOBOOL]], [[CMP]]
; CHECK-NEXT: call void @use1(i1 [[OR]])
[InstCombine] remove a buggy set of zext-icmp transforms The motivating case is an infinite loop shown with a reduced test from: https://llvm.org/PR51762 To solve this, I'm proposing we delete the most obviously broken part of this code. The bug example shows a fundamental problem: we ask computeKnownBits if a transform will be profitable, alter the code by creating new instructions, then rely on computeKnownBits to return the same answer to actually eliminate instructions. But there's no guarantee that the results will be the same between the 1st and 2nd calls. In the infinite loop example, we get different answers, so we add instructions that conflict with some other transform, and we're stuck. There's at least one other problem visible in the test diff for `@zext_or_masked_bit_test_uses`: the code doesn't check uses properly, so we can end up with extra instructions created. Last, it's not clear if this set of transforms actually improves analysis or codegen. I spot-checked a few targets and don't see a clear win: https://godbolt.org/z/x87EWovso If we do see a regression from this change, codegen seems like the right place to add a cmp -> bit-hack fold. If this is too big of a step, we could limit the computeKnownBits calls by not passing a context instruction and/or limiting the recursion. I checked that those would stop the infinite loop for PR51762, but that won't guarantee that some other example does not fall into the same loop. Differential Revision: https://reviews.llvm.org/D109440
2021-09-09 20:45:56 +08:00
; CHECK-NEXT: [[Z:%.*]] = zext i1 [[OR]] to i32
; CHECK-NEXT: ret i32 [[Z]]
;
%shl = shl i32 1, %b
%and = and i32 %shl, %a
%tobool = icmp ne i32 %and, 0
%cmp = icmp eq i32 %x, %b
%or = or i1 %tobool, %cmp
call void @use1(i1 %or)
%z = zext i1 %or to i32
ret i32 %z
}