[Inline] Avoid incompatible return attributes on deoptimize

[anna]

Summary

When updating the return type of deoptimize call during inline, we need to drop incompatible return attributes.
This bug was exposed once we relaxed the contraint of adding the attributes through D156844. With that
change deoptimize (are not willreturn) will start having return attributes added to it.

Fix https://github.com/llvm/llvm-project/issues/64804.

[nikic]

Where is this update done? Shouldn't the code changing the return type drop incompatible attributes?

[anna]

In D158286#4599153, @nikic wrote:

Where is this update done? Shouldn't the code changing the return type drop incompatible attributes?

yeah, that's better. Will update.

[anna]

remove incompatible return attributes at the point we change the return type.

[anna]

One thing to note though is we would need to future proof against incompatible types (whenever new return types are added), but that happens in the common API: AttributeFuncs::typeIncompatible.

[nikic]

llvm/lib/IR/Attributes.cpp

1999 ↗

(On Diff #551536)

This change is unnecessary, this is all handled by !Ty->isPointerTy() above.

[anna]

llvm/lib/IR/Attributes.cpp

1999 ↗

(On Diff #551536)

good point.

[anna]

addressed review comment.

[nikic]

LG

llvm/lib/Transforms/Utils/InlineFunction.cpp

 #include "llvm/Analysis/CaptureTracking.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemoryProfileInfo.h"
 #include "llvm/Analysis/ObjCARCAnalysisUtils.h"
 #include "llvm/Analysis/ObjCARCUtil.h"
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/Analysis/VectorUtils.h"
+#include "llvm/IR/AttributeMask.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DebugInfoMetadata.h"
if (Caller->getReturnType() == CB.getType()) {
         CallInst *NewDeoptCall =
             Builder.CreateCall(NewDeoptIntrinsic, CallArgs, OpBundles);
         NewDeoptCall->setCallingConv(CallingConv);
         NewDeoptCall->setAttributes(DeoptAttributes);
         if (NewDeoptCall->getType()->isVoidTy())
           Builder.CreateRetVoid();
         else
           Builder.CreateRet(NewDeoptCall);
+        // Since the ret type is changed, remove the incompatible attributes.
+        NewDeoptCall->removeRetAttrs(
+            AttributeFuncs::typeIncompatible(NewDeoptCall->getType()));
       }
 
       // Leave behind the normal returns so we can merge control flow.
       std::swap(Returns, NormalReturns);
     }
   }
 
   // Handle any inlined musttail call sites.  In order for a new call site to be

llvm/test/Transforms/Inline/pr64804.ll

+; RUN: opt -S -passes=inline < %s | FileCheck %s
+
+declare ptr @llvm.experimental.deoptimize.p0(...)
+
+; Make sure we do not add incompatible attribute (noalias) to the deoptimize call.
+
+define ptr @callee_noalias(ptr %c) {
+  %v2 = call ptr (...) @llvm.experimental.deoptimize.p0(i32 42 ) [ "deopt"(i32 1) ]
+  ret ptr %v2
+}
+
+; CHECK-LABEL: caller_noalias
+; CHECK: call void (...) @llvm.experimental.deoptimize.isVoid(i32 42) [ "deopt"(i32 2, i32 1) ]
+define void @caller_noalias(ptr %c) {
+entry:
+  %v = call noalias ptr @callee_noalias(ptr %c)  [ "deopt"(i32 2) ]
+  ret void
+}