From d40a07ce4e3d16178f4295c49b88c4e1c8aa5758 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Tue, 10 Nov 2015 23:22:20 +0000
Subject: [PATCH] [WinEH] Insert the MBB for EH_RESTORE after the catchret

Inserting it before the target block could be bad, we might already have
a fallthrough edge to it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252670 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp       |  2 +-
 test/CodeGen/X86/catchret-fallthrough.ll | 46 ++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/X86/catchret-fallthrough.ll

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 4daa74b34fd..9513176f99b 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -21416,7 +21416,7 @@ X86TargetLowering::EmitLoweredCatchRet(MachineInstr *MI,
   MachineBasicBlock *RestoreMBB =
       MF->CreateMachineBasicBlock(BB->getBasicBlock());
   assert(BB->succ_size() == 1);
-  MF->insert(TargetMBB->getIterator(), RestoreMBB);
+  MF->insert(std::next(BB->getIterator()), RestoreMBB);
   RestoreMBB->transferSuccessorsAndUpdatePHIs(BB);
   BB->addSuccessor(RestoreMBB);
   MI->getOperand(0).setMBB(RestoreMBB);
diff --git a/test/CodeGen/X86/catchret-fallthrough.ll b/test/CodeGen/X86/catchret-fallthrough.ll
new file mode 100644
index 00000000000..497f6fb3a9d
--- /dev/null
+++ b/test/CodeGen/X86/catchret-fallthrough.ll
@@ -0,0 +1,46 @@
+; RUN: llc -verify-machineinstrs < %s | FileCheck %s
+
+; We used to have an issue where we inserted an MBB between invoke.cont.3 and
+; its fallthrough target of ret void.
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i386-pc-windows-msvc18.0.0"
+
+@some_global = global i32 0
+
+declare i32 @__CxxFrameHandler3(...)
+
+declare void @g()
+
+define void @f() personality i32 (...)* @__CxxFrameHandler3 {
+entry:
+  invoke void @g()
+          to label %invoke.cont.3 unwind label %catch.dispatch
+
+catch.dispatch:                                   ; preds = %entry
+  %0 = catchpad [i8* null, i32 64, i8* null]
+          to label %catch unwind label %catchendblock
+
+catch:                                            ; preds = %catch.dispatch
+  catchret %0 to label %nrvo.skipdtor
+
+catchendblock:                                    ; preds = %catch, %catch.dispatch
+  catchendpad unwind to caller
+
+invoke.cont.3:                                    ; preds = %entry
+  store i32 123, i32* @some_global
+  br label %nrvo.skipdtor
+
+nrvo.skipdtor:                                    ; preds = %invoke.cont.3, %invoke.cont.4
+  ret void
+}
+
+; CHECK-LABEL: _f: # @f
+; CHECK: calll _g
+; CHECK: movl $123, _some_global
+; CHECK-NOT: jmp
+; CHECK-NOT: movl {{.*}}, %esp
+; CHECK: retl
+; CHECK: movl {{.*}}, %esp
+; CHECK: addl $12, %ebp
+; CHECK: jmp LBB0_{{.*}}
-- 
2.34.1