[InstCombine] Drop samesign in InstCombinerImpl::foldICmpAndConstConst

dtcxzyw · dtcxzyw · commit e1c281dc421a · 2024-10-16T13:20:36.000+08:00
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -1844,6 +1844,7 @@ Instruction *InstCombinerImpl::foldICmpAndConstConst(ICmpInst &Cmp,
                                                /*HasNUW=*/true),
                              One, Or->getName());
         Value *NewAnd = Builder.CreateAnd(A, NewOr, And->getName());
+        Cmp.setSameSign(false);
         return replaceOperand(Cmp, 0, NewAnd);
       }
     }
diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll
@@ -3208,7 +3208,7 @@ define i1 @icmp_and_or_lshr_samesign(i32 %x, i32 %y) {
 ; CHECK-NEXT:    [[SHF1:%.*]] = shl nuw i32 1, [[Y:%.*]]
 ; CHECK-NEXT:    [[OR2:%.*]] = or i32 [[SHF1]], 1
 ; CHECK-NEXT:    [[AND3:%.*]] = and i32 [[X:%.*]], [[OR2]]
-; CHECK-NEXT:    [[RET:%.*]] = icmp samesign ne i32 [[AND3]], 0
+; CHECK-NEXT:    [[RET:%.*]] = icmp ne i32 [[AND3]], 0
 ; CHECK-NEXT:    ret i1 [[RET]]
 ;
   %shf = lshr i32 %x, %y

Original file line number	Diff line number	Diff line change
`@@ -1844,6 +1844,7 @@ Instruction *InstCombinerImpl::foldICmpAndConstConst(ICmpInst &Cmp,`
`1844`	`1844`	`/HasNUW=/true),`
`1845`	`1845`	`One, Or->getName());`
`1846`	`1846`	`Value *NewAnd = Builder.CreateAnd(A, NewOr, And->getName());`
	`1847`	`+ Cmp.setSameSign(false);`
`1847`	`1848`	`return replaceOperand(Cmp, 0, NewAnd);`
`1848`	`1849`	`}`
`1849`	`1850`	`}`
Original file line number	Diff line number	Diff line change
`@@ -3208,7 +3208,7 @@ define i1 @icmp_and_or_lshr_samesign(i32 %x, i32 %y) {`
`3208`	`3208`	`; CHECK-NEXT: [[SHF1:%.]] = shl nuw i32 1, [[Y:%.]]`
`3209`	`3209`	`; CHECK-NEXT: [[OR2:%.*]] = or i32 [[SHF1]], 1`
`3210`	`3210`	`; CHECK-NEXT: [[AND3:%.]] = and i32 [[X:%.]], [[OR2]]`
`3211`		`-; CHECK-NEXT: [[RET:%.*]] = icmp samesign ne i32 [[AND3]], 0`
	`3211`	`+; CHECK-NEXT: [[RET:%.*]] = icmp ne i32 [[AND3]], 0`
`3212`	`3212`	`; CHECK-NEXT: ret i1 [[RET]]`
`3213`	`3213`	`;`
`3214`	`3214`	`%shf = lshr i32 %x, %y`