[llvm-branch-commits] [llvm] 186df07 - [DSE] Remove `uninitialized` from `allockind` when creating dummy zeroed variant function (#149336)

[Tobias Hieta via llvm-branch-commits]

Author: clubby789
Date: 2025-07-22T10:31:55+02:00
New Revision: 186df07d013b5c3f158d22f3e7687723fbcc775b

URL: https://github.com/llvm/llvm-project/commit/186df07d013b5c3f158d22f3e7687723fbcc775b
DIFF: https://github.com/llvm/llvm-project/commit/186df07d013b5c3f158d22f3e7687723fbcc775b.diff

LOG: [DSE] Remove `uninitialized` from `allockind` when creating dummy zeroed variant function (#149336)

cc https://github.com/llvm/llvm-project/pull/138299

rustc sets `allockind("uninitialized")` - if we copy the attributes
as-is when creating a dummy function, Verify complains about
`allockind("uninitialized,zeroed")` conflicting, so we need to clear the
flag.

Co-authored-by: Jamie Hill-Daniel <jamie at osec.io>
(cherry picked from commit 74c396afb26dec74c0b799e218c63f1a26e90d21)

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
    llvm/test/Transforms/DeadStoreElimination/zeroed-missing.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 85dd9a1bf7161..0f63ed0166cf4 100644
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -2079,6 +2079,7 @@ struct DSEState {
       AllocFnKind AllocKind =
           Attrs.getFnAttr(Attribute::AllocKind).getAllocKind() |
           AllocFnKind::Zeroed;
+      AllocKind &= ~AllocFnKind::Uninitialized;
       Attrs =
           Attrs.addFnAttribute(Ctx, Attribute::getWithAllocKind(Ctx, AllocKind))
               .removeFnAttribute(Ctx, "alloc-variant-zeroed");

diff  --git a/llvm/test/Transforms/DeadStoreElimination/zeroed-missing.ll b/llvm/test/Transforms/DeadStoreElimination/zeroed-missing.ll
index e390d4bdca632..303afc207c023 100644
--- a/llvm/test/Transforms/DeadStoreElimination/zeroed-missing.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/zeroed-missing.ll
@@ -12,6 +12,6 @@ define ptr @undeclared_customalloc(i64 %size, i64 %align) {
   ret ptr %call
 }
 
-declare ptr @customalloc2(i64, i64) allockind("alloc") "alloc-family"="customalloc2" "alloc-variant-zeroed"="customalloc2_zeroed"
+declare ptr @customalloc2(i64, i64) allockind("alloc,uninitialized") "alloc-family"="customalloc2" "alloc-variant-zeroed"="customalloc2_zeroed"
 ; CHECK-DAG: declare ptr @customalloc2_zeroed(i64, i64) #[[CA2ATTR:[0-9]+]]
 ; CHECK-DAG: attributes #[[CA2ATTR]] = { allockind("alloc,zeroed") "alloc-family"="customalloc2" }