[ValueTracking] Dereferenceable ret attributes implys noundef

Reviewed By: nikic Differential Revision: https://reviews.llvm.org/D156510
llvm · Aug 7, 2023 · 4e84ec8 · 4e84ec8
1 parent bcfdb3e
commit 4e84ec8
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
@@ -6757,7 +6757,9 @@ static bool isGuaranteedNotToBeUndefOrPoison(const Value *V,
       return true;
 
     if (const auto *CB = dyn_cast<CallBase>(V)) {
-      if (CB->hasRetAttr(Attribute::NoUndef))
+      if (CB->hasRetAttr(Attribute::NoUndef) ||
+          CB->hasRetAttr(Attribute::Dereferenceable) ||
+          CB->hasRetAttr(Attribute::DereferenceableOrNull))
         return true;
     }
 

diff --git a/llvm/test/Transforms/Attributor/memory_locations.ll b/llvm/test/Transforms/Attributor/memory_locations.ll
@@ -195,7 +195,7 @@ define dso_local ptr @internal_argmem_only_write(ptr %arg) {
 ; CHECK-SAME: (ptr nocapture nofree noundef nonnull writeonly align 4 dereferenceable(4) [[ARG:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    store i32 10, ptr [[ARG]], align 4
-; CHECK-NEXT:    [[CALL:%.*]] = call noalias dereferenceable_or_null(10) ptr @malloc(i64 noundef 10)
+; CHECK-NEXT:    [[CALL:%.*]] = call noalias noundef dereferenceable_or_null(10) ptr @malloc(i64 noundef 10)
 ; CHECK-NEXT:    ret ptr [[CALL]]
 ;
 entry: