[llvm] f36703a - [SjLj] Insert UnregisterFn before musttail call
Xun Li via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 23 14:29:53 PDT 2021
Author: Xun Li
Date: 2021-06-23T14:29:46-07:00
New Revision: f36703ada3dc18388ef5cdcbb8f39f74c27ad8e9
URL: https://github.com/llvm/llvm-project/commit/f36703ada3dc18388ef5cdcbb8f39f74c27ad8e9
DIFF: https://github.com/llvm/llvm-project/commit/f36703ada3dc18388ef5cdcbb8f39f74c27ad8e9.diff
LOG: [SjLj] Insert UnregisterFn before musttail call
When inserting UnregisterFn, if there is a musttail call, we must insert before the call so that we don't break the musttail call contract.
Differential Revision: https://reviews.llvm.org/D104807
Added:
llvm/test/CodeGen/X86/sjlj-eh-musttail.ll
Modified:
llvm/lib/CodeGen/SjLjEHPrepare.cpp
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/SjLjEHPrepare.cpp b/llvm/lib/CodeGen/SjLjEHPrepare.cpp
index d2fd4a6d8fd9..8211e3d6a9dd 100644
--- a/llvm/lib/CodeGen/SjLjEHPrepare.cpp
+++ b/llvm/lib/CodeGen/SjLjEHPrepare.cpp
@@ -472,8 +472,12 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
// Finally, for any returns from this function, if this function contains an
// invoke, add a call to unregister the function context.
- for (ReturnInst *Return : Returns)
- CallInst::Create(UnregisterFn, FuncCtx, "", Return);
+ for (ReturnInst *Return : Returns) {
+ Instruction *InsertPoint = Return;
+ if (CallInst *CI = Return->getParent()->getTerminatingMustTailCall())
+ InsertPoint = CI;
+ CallInst::Create(UnregisterFn, FuncCtx, "", InsertPoint);
+ }
return true;
}
diff --git a/llvm/test/CodeGen/X86/sjlj-eh-musttail.ll b/llvm/test/CodeGen/X86/sjlj-eh-musttail.ll
new file mode 100644
index 000000000000..52766d668db9
--- /dev/null
+++ b/llvm/test/CodeGen/X86/sjlj-eh-musttail.ll
@@ -0,0 +1,30 @@
+; RUN: llc -mtriple i386-windows-gnu -exception-model sjlj -filetype asm -o - %s | FileCheck %s
+
+declare void @_Z20function_that_throwsv()
+declare i32 @__gxx_personality_sj0(...)
+declare i8* @__cxa_begin_catch(i8*)
+declare void @__cxa_end_catch()
+declare void @_callee();
+
+define void @_Z8functionv() personality i8* bitcast (i32 (...)* @__gxx_personality_sj0 to i8*) {
+entry:
+ invoke void @_Z20function_that_throwsv()
+ to label %try.cont unwind label %lpad
+
+lpad:
+ %0 = landingpad { i8*, i32 }
+ catch i8* null
+ %1 = extractvalue { i8*, i32 } %0, 0
+ %2 = tail call i8* @__cxa_begin_catch(i8* %1)
+ tail call void @__cxa_end_catch()
+ br label %try.cont
+
+try.cont:
+ musttail call void @_callee();
+ ret void
+}
+
+; CHECK-LABEL: __Z8functionv:
+; CHECK: calll __Unwind_SjLj_Unregister
+; CHECK-NOT: {{.*}}:
+; CHECK: jmp __callee
More information about the llvm-commits
mailing list