Don't constant propagate byval pointers, since they are not really pointers, but
authorTorok Edwin <edwintorok@gmail.com>
Thu, 24 Sep 2009 09:47:18 +0000 (09:47 +0000)
committerTorok Edwin <edwintorok@gmail.com>
Thu, 24 Sep 2009 09:47:18 +0000 (09:47 +0000)
rather structs passed by value.
This fixes PR5038.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82689 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/IPConstantPropagation.cpp
lib/Transforms/Scalar/SCCP.cpp
test/Transforms/IPConstantProp/2009-09-24-byval-ptr.ll [new file with mode: 0644]

index bb24486..95c3f4e 100644 (file)
@@ -130,7 +130,8 @@ bool IPCP::PropagateConstantsIntoArguments(Function &F) {
   Function::arg_iterator AI = F.arg_begin();
   for (unsigned i = 0, e = ArgumentConstants.size(); i != e; ++i, ++AI) {
     // Do we have a constant argument?
-    if (ArgumentConstants[i].second || AI->use_empty())
+    if (ArgumentConstants[i].second || AI->use_empty() || 
+        (AI->hasByValAttr() && isa<PointerType>(AI->getType())))
       continue;
   
     Value *V = ArgumentConstants[i].first;
index f0b5d77..bf9ec0e 100644 (file)
@@ -1267,6 +1267,10 @@ CallOverdefined:
   for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
        AI != E; ++AI, ++CAI) {
     LatticeVal &IV = ValueState[AI];
+    if (AI->hasByValAttr() && isa<PointerType>(AI->getType())) {
+      IV.markOverdefined();
+      continue;
+    }
     if (!IV.isOverdefined())
       mergeInValue(IV, AI, getValueState(*CAI));
   }
diff --git a/test/Transforms/IPConstantProp/2009-09-24-byval-ptr.ll b/test/Transforms/IPConstantProp/2009-09-24-byval-ptr.ll
new file mode 100644 (file)
index 0000000..75055d4
--- /dev/null
@@ -0,0 +1,24 @@
+; RUN: llvm-as <%s | opt -ipsccp | llvm-dis | FileCheck %s
+; Don't constant-propagate byval pointers, since they are not pointers!
+; PR5038
+%struct.MYstr = type { i8, i32 }
+@mystr = internal global %struct.MYstr zeroinitializer ; <%struct.MYstr*> [#uses=3]
+define internal void @vfu1(%struct.MYstr* byval align 4 %u) nounwind {
+entry:
+  %0 = getelementptr %struct.MYstr* %u, i32 0, i32 1 ; <i32*> [#uses=1]
+  store i32 99, i32* %0, align 4
+; CHECK: %struct.MYstr* %u
+  %1 = getelementptr %struct.MYstr* %u, i32 0, i32 0 ; <i8*> [#uses=1]
+  store i8 97, i8* %1, align 4
+; CHECK: %struct.MYstr* %u
+  br label %return
+
+return:                                           ; preds = %entry
+  ret void
+}
+define void @unions() nounwind {
+entry:
+  call void @vfu1(%struct.MYstr* byval align 4 @mystr) nounwind
+  ret void
+}
+