[llvm] [WinEH] Fix asm in catchpad being turned into unreachable (PR #138392)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-platform-windows

Author: None (Ralender)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/138392.diff


2 Files Affected:

- (modified) llvm/lib/CodeGen/WinEHPrepare.cpp (+2-2) 
- (added) llvm/test/CodeGen/WinEH/wineh-asm2.ll (+46) 


``````````diff
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 74cef6c134736..43dd651a686b9 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -1135,8 +1135,8 @@ void WinEHPrepareImpl::removeImplausibleInstructions(Function &F) {
         // Skip call sites which are nounwind intrinsics or inline asm.
         auto *CalledFn =
             dyn_cast<Function>(CB->getCalledOperand()->stripPointerCasts());
-        if (CalledFn && ((CalledFn->isIntrinsic() && CB->doesNotThrow()) ||
-                         CB->isInlineAsm()))
+        if (CB->isInlineAsm() ||
+            (CalledFn && CalledFn->isIntrinsic() && CB->doesNotThrow()))
           continue;
 
         // This call site was not part of this funclet, remove it.
diff --git a/llvm/test/CodeGen/WinEH/wineh-asm2.ll b/llvm/test/CodeGen/WinEH/wineh-asm2.ll
new file mode 100644
index 0000000000000..2c424536dca09
--- /dev/null
+++ b/llvm/test/CodeGen/WinEH/wineh-asm2.ll
@@ -0,0 +1,46 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=win-eh-prepare -S | FileCheck %s
+
+target triple = "x86_64-unknown-windows-msvc"
+
+%rtti.TypeDescriptor2 = type { ptr, ptr, [3 x i8] }
+
+$"??_R0H at 8" = comdat any
+
+@"??_7type_info@@6B@" = external constant ptr
+@"??_R0H at 8" = linkonce_odr global %rtti.TypeDescriptor2 { ptr @"??_7type_info@@6B@", ptr null, [3 x i8] c".H\00" }, comdat
+
+declare dso_local i32 @test0(i32) local_unnamed_addr
+
+define dso_local i32 @test1(i32 %argc) local_unnamed_addr personality ptr @__CxxFrameHandler3 {
+; CHECK-LABEL: define dso_local i32 @test1(
+; CHECK-SAME: i32 [[ARGC:%.*]]) local_unnamed_addr personality ptr @__CxxFrameHandler3 {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[CALL:%.*]] = invoke i32 @test0(i32 [[ARGC]])
+; CHECK-NEXT:            to label %[[RETURN:.*]] unwind label %[[CATCH_DISPATCH:.*]]
+; CHECK:       [[CATCH_DISPATCH]]:
+; CHECK-NEXT:    [[TMP0:%.*]] = catchswitch within none [label %catch] unwind to caller
+; CHECK:       [[CATCH:.*:]]
+; CHECK-NEXT:    [[TMP1:%.*]] = catchpad within [[TMP0]] [ptr @"??_R0H at 8", i32 0, ptr null]
+; CHECK-NEXT:    call void asm "", ""()
+; CHECK-NEXT:    catchret from [[TMP1]] to label %[[RETURN]]
+; CHECK:       [[RETURN]]:
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  %call = invoke i32 @test0(i32 %argc)
+  to label %return unwind label %catch.dispatch
+
+catch.dispatch:                                   ; preds = %entry
+  %0 = catchswitch within none [label %catch] unwind to caller
+
+catch:                                            ; preds = %catch.dispatch
+  %1 = catchpad within %0 [ptr @"??_R0H at 8", i32 0, ptr null]
+  call void asm "", ""()
+  catchret from %1 to label %return
+
+return:                                           ; preds = %catch, %entry
+  ret i32 0
+}
+
+declare dso_local i32 @__CxxFrameHandler3(...)

``````````

</details>


https://github.com/llvm/llvm-project/pull/138392