[llvm] 2fbd088 - [InstCombine] Queue Xor for deletion after replacing its uses in freelyInvertAllUsersOf. (#72445)
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Thu Nov 16 09:46:39 PST 2023
Author: Craig Topper
Date: 2023-11-16T09:46:34-08:00
New Revision: 2fbd0885246cf687f388620318d6954b0984fcba
URL: https://github.com/llvm/llvm-project/commit/2fbd0885246cf687f388620318d6954b0984fcba
DIFF: https://github.com/llvm/llvm-project/commit/2fbd0885246cf687f388620318d6954b0984fcba.diff
LOG: [InstCombine] Queue Xor for deletion after replacing its uses in freelyInvertAllUsersOf. (#72445)
Fixes #72433
Added:
llvm/test/Transforms/InstCombine/pr72433.ll
Modified:
llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 16de4e3ffe1f51a..463a7b5bb1bb588 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1185,6 +1185,8 @@ void InstCombinerImpl::freelyInvertAllUsersOf(Value *I, Value *IgnoredUser) {
break;
case Instruction::Xor:
replaceInstUsesWith(cast<Instruction>(*U), I);
+ // Add to worklist for DCE.
+ addToWorklist(cast<Instruction>(U));
break;
default:
llvm_unreachable("Got unexpected user - out of sync with "
diff --git a/llvm/test/Transforms/InstCombine/pr72433.ll b/llvm/test/Transforms/InstCombine/pr72433.ll
new file mode 100644
index 000000000000000..ec3fcfcfea46fcf
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/pr72433.ll
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=instcombine -S < %s | FileCheck %s
+
+define i32 @widget(i32 %arg, i32 %arg1) {
+; CHECK-LABEL: define i32 @widget(
+; CHECK-SAME: i32 [[ARG:%.*]], i32 [[ARG1:%.*]]) {
+; CHECK-NEXT: bb:
+; CHECK-NEXT: [[ICMP:%.*]] = icmp ne i32 [[ARG]], 0
+; CHECK-NEXT: [[TMP0:%.*]] = zext i1 [[ICMP]] to i32
+; CHECK-NEXT: [[MUL:%.*]] = shl nuw nsw i32 20, [[TMP0]]
+; CHECK-NEXT: [[XOR:%.*]] = zext i1 [[ICMP]] to i32
+; CHECK-NEXT: [[ADD9:%.*]] = or i32 [[MUL]], [[XOR]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i1 [[ICMP]] to i32
+; CHECK-NEXT: [[MUL2:%.*]] = shl nuw nsw i32 [[ADD9]], [[TMP1]]
+; CHECK-NEXT: ret i32 [[MUL2]]
+;
+bb:
+ %icmp = icmp eq i32 %arg, 0
+ %zext = zext i1 %icmp to i32
+ %sub = sub i32 2, %zext
+ %mul = mul i32 20, %sub
+ %zext8 = zext i1 %icmp to i32
+ %xor = xor i32 %zext8, 1
+ %add9 = add i32 %mul, %xor
+ %mul2 = mul i32 %add9, %sub
+ ret i32 %mul2
+}
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