[llvm] 67aed14 - [Attributor] Do not set 'returned' attribute for arguments that cannot be bitcasted to function result

[Sergey Dmitriev via llvm-commits]

Author: Sergey Dmitriev
Date: 2020-04-25T09:49:40-07:00
New Revision: 67aed1469b0f5b5f7e3f18acfebc97eb34ffbad0

URL: https://github.com/llvm/llvm-project/commit/67aed1469b0f5b5f7e3f18acfebc97eb34ffbad0
DIFF: https://github.com/llvm/llvm-project/commit/67aed1469b0f5b5f7e3f18acfebc97eb34ffbad0.diff

LOG: [Attributor] Do not set 'returned' attribute for arguments that cannot be bitcasted to function result

Reviewers: jdoerfert, sstefan1, uenoku

Reviewed By: jdoerfert

Subscribers: hiraditya, uenoku, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78828

Added: 
    llvm/test/Transforms/Attributor/returned_crash.ll

Modified: 
    llvm/lib/Transforms/IPO/AttributorAttributes.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 8573040a3fd4..aeb1029ed002 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -906,10 +906,13 @@ ChangeStatus AAReturnedValuesImpl::manifest(Attributor &A) {
 
   // If the assumed unique return value is an argument, annotate it.
   if (auto *UniqueRVArg = dyn_cast<Argument>(UniqueRV.getValue())) {
-    // TODO: This should be handled 
diff erently!
-    this->AnchorVal = UniqueRVArg;
-    this->KindOrArgNo = UniqueRVArg->getArgNo();
-    Changed = IRAttribute::manifest(A);
+    if (UniqueRVArg->getType()->canLosslesslyBitCastTo(
+            getAssociatedFunction()->getReturnType())) {
+      // TODO: This should be handled 
diff erently!
+      this->AnchorVal = UniqueRVArg;
+      this->KindOrArgNo = UniqueRVArg->getArgNo();
+      Changed = IRAttribute::manifest(A);
+    }
   } else if (auto *RVC = dyn_cast<Constant>(UniqueRV.getValue())) {
     // We can replace the returned value with the unique returned constant.
     Value &AnchorValue = getAnchorValue();

diff  --git a/llvm/test/Transforms/Attributor/returned_crash.ll b/llvm/test/Transforms/Attributor/returned_crash.ll
new file mode 100644
index 000000000000..d9af2e180340
--- /dev/null
+++ b/llvm/test/Transforms/Attributor/returned_crash.ll
@@ -0,0 +1,9 @@
+; RUN: opt -attributor -S %s | FileCheck %s
+; RUN: opt -passes=attributor -S %s | FileCheck %s
+;
+; CHECK: define i32 addrspace(1)* @foo(i32 addrspace(4)* nofree readnone %arg)
+define i32 addrspace(1)* @foo(i32 addrspace(4)* %arg) {
+entry:
+  %0 = addrspacecast i32 addrspace(4)* %arg to i32 addrspace(1)*
+  ret i32 addrspace(1)* %0
+}