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[InstCombine] Fix bug when folding x + (x | -x) to x & (x - 1) 

Addresses concern: https://reviews.llvm.org/rG09cdddea0c4d284c2c22f5dfade40a60850c5ea7

There was a copy/paste mistake in the code. Updated code and test ref.

Differential Revision: https://reviews.llvm.org/D134135
This commit is contained in:
Marc Auberer 2022-09-18 13:16:12 -04:00 committed by Sanjay Patel
parent 1d1d1e6f22
commit f52dd920d4
2 changed files with 5 additions and 5 deletions
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2
llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
View File

@ -1404,7 +1404,7 @@ Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
m_Deferred(A)))))) {
Value *Add =
Builder.CreateAdd(A, Constant::getAllOnesValue(A->getType()), "",
I.hasNoSignedWrap(), I.hasNoSignedWrap());
I.hasNoUnsignedWrap(), I.hasNoSignedWrap());
return BinaryOperator::CreateAnd(Add, A);
}

8
llvm/test/Transforms/InstCombine/add_or_sub.ll
View File

@ -7,9 +7,7 @@ declare void @use2(i2)
define i32 @add_or_sub_comb_i32_commuted1_nuw(i32 %x) {
; CHECK-LABEL: @add_or_sub_comb_i32_commuted1_nuw(
; CHECK-NEXT: [[TMP1:%.*]] = add i32 [[X:%.*]], -1
; CHECK-NEXT: [[ADD:%.*]] = and i32 [[TMP1]], [[X]]
; CHECK-NEXT: ret i32 [[ADD]]
; CHECK-NEXT: ret i32 [[X:%.*]]
;
%sub = sub i32 0, %x
%or = or i32 %sub, %x
@ -20,7 +18,9 @@ define i32 @add_or_sub_comb_i32_commuted1_nuw(i32 %x) {
define i8 @add_or_sub_comb_i8_commuted2_nsw(i8 %p) {
; CHECK-LABEL: @add_or_sub_comb_i8_commuted2_nsw(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[P:%.*]], [[P]]
; CHECK-NEXT: ret i8 [[X]]
; CHECK-NEXT: [[TMP1:%.*]] = add nsw i8 [[X]], -1
; CHECK-NEXT: [[ADD:%.*]] = and i8 [[TMP1]], [[X]]
; CHECK-NEXT: ret i8 [[ADD]]
;
%x = mul i8 %p, %p ; thwart complexity-based canonicalization
%sub = sub i8 0, %x