[Attributor][FIX] Store alignment only holds for the pointer value

We accidentally used the store alignment for the value operand as well,
which is incorrect and crashed the SPASS application in the test suite.

diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index baa1cb1..5eb21a0 100644 (file)
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -3420,9 +3420,10 @@ static unsigned int getKnownAlignForUse(Attributor &A,
   }
 
   const Value *UseV = U->get();
-  if (auto *SI = dyn_cast<StoreInst>(I))
-    Alignment = SI->getAlignment();
-  else if (auto *LI = dyn_cast<LoadInst>(I))
+  if (auto *SI = dyn_cast<StoreInst>(I)) {
+    if (SI->getPointerOperand() == UseV)
+      Alignment = SI->getAlignment();
+  } else if (auto *LI = dyn_cast<LoadInst>(I))
     Alignment = LI->getAlignment();
 
   if (Alignment <= 1)

diff --git a/llvm/test/Transforms/Attributor/align.ll b/llvm/test/Transforms/Attributor/align.ll
index e47141c..d961a18 100644 (file)
--- a/llvm/test/Transforms/Attributor/align.ll
+++ b/llvm/test/Transforms/Attributor/align.ll
@@ -501,6 +501,13 @@ define i64* @int2ptr(i64 %i) {
   ret i64* %i2p
 }
 
+; Use the store alignment only for the pointer operand.
+define void @aligned_store(i8* %Value, i8** %Ptr) {
+; ATTRIBUTOR: define void @aligned_store(i8* nofree writeonly %Value, i8** nocapture nofree nonnull writeonly align 32 dereferenceable(8) %Ptr)
+  store i8* %Value, i8** %Ptr, align 32
+  ret void
+}
+
 attributes #0 = { nounwind uwtable noinline }
 attributes #1 = { uwtable noinline }
 attributes #2 = { "null-pointer-is-valid"="true" }