[llvm] e7618a6 - [GVN] Fix change reporting when removing assume (PR61574)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-03-22T15:23:31+01:00
New Revision: e7618a6361f856a089d6f9eb476f18a9bf4643b8

URL: https://github.com/llvm/llvm-project/commit/e7618a6361f856a089d6f9eb476f18a9bf4643b8
DIFF: https://github.com/llvm/llvm-project/commit/e7618a6361f856a089d6f9eb476f18a9bf4643b8.diff

LOG: [GVN] Fix change reporting when removing assume (PR61574)

Report a change when removing a true/false assume.

Fixes https://github.com/llvm/llvm-project/issues/61574.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/GVN.cpp
    llvm/test/Transforms/GVN/assume.ll

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index 28b1f455459f..0c263e5644b6 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -1908,8 +1908,10 @@ bool GVNPass::processAssumeIntrinsic(AssumeInst *IntrinsicI) {
         MSSAU->insertDef(cast<MemoryDef>(NewDef), /*RenameUses=*/false);
       }
     }
-    if (isAssumeWithEmptyBundle(*IntrinsicI))
+    if (isAssumeWithEmptyBundle(*IntrinsicI)) {
       markInstructionForDeletion(IntrinsicI);
+      return true;
+    }
     return false;
   } else if (isa<Constant>(V)) {
     // If it's not false, and constant, it must evaluate to true. This means our

diff  --git a/llvm/test/Transforms/GVN/assume.ll b/llvm/test/Transforms/GVN/assume.ll
index 3b6346f63dbb..6cb4c871750d 100644
--- a/llvm/test/Transforms/GVN/assume.ll
+++ b/llvm/test/Transforms/GVN/assume.ll
@@ -1,9 +1,26 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -passes=gvn -S | FileCheck %s
+; RUN: opt < %s -passes=gvn -verify-analysis-invalidation -S | FileCheck %s
 
 declare void @llvm.assume(i1)
 declare void @use(i1)
 
+define void @assume_true() {
+; CHECK-LABEL: @assume_true(
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.assume(i1 true)
+  ret void
+}
+
+define void @assume_false() {
+; CHECK-LABEL: @assume_false(
+; CHECK-NEXT:    store i8 poison, ptr null, align 1
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.assume(i1 false)
+  ret void
+}
+
 define void @assume_arg(i1 %x) {
 ; CHECK-LABEL: @assume_arg(
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[X:%.*]])