From 0abc36205a39f3791342165502478bb51fe67f05 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Sun, 20 Oct 2013 02:16:21 +0000
Subject: [PATCH] Emit prefix data after debug and EH directives.

This ensures that the prefix data is treated as part of the function for
the purpose of debug info.  This provides a better debugging experience,
among other things by allowing a debug info client to correctly look up
a function in debug info given a function pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193042 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 8 ++++----
 test/CodeGen/X86/prefixdata.ll        | 2 ++
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 0fe341a2431..969a8dfeaea 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -462,10 +462,6 @@ void AsmPrinter::EmitFunctionHeader() {
     OutStreamer.EmitLabel(DeadBlockSyms[i]);
   }
 
-  // Emit the prefix data.
-  if (F->hasPrefixData())
-    EmitGlobalConstant(F->getPrefixData());
-
   // Emit pre-function debug and/or EH information.
   if (DE) {
     NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
@@ -475,6 +471,10 @@ void AsmPrinter::EmitFunctionHeader() {
     NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
     DD->beginFunction(MF);
   }
+
+  // Emit the prefix data.
+  if (F->hasPrefixData())
+    EmitGlobalConstant(F->getPrefixData());
 }
 
 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
diff --git a/test/CodeGen/X86/prefixdata.ll b/test/CodeGen/X86/prefixdata.ll
index 2ffa89d287d..2ec1892dd18 100644
--- a/test/CodeGen/X86/prefixdata.ll
+++ b/test/CodeGen/X86/prefixdata.ll
@@ -3,12 +3,14 @@
 @i = linkonce_odr global i32 1
 
 ; CHECK: f:
+; CHECK-NEXT: .cfi_startproc
 ; CHECK-NEXT: .long	1
 define void @f() prefix i32 1 {
   ret void
 }
 
 ; CHECK: g:
+; CHECK-NEXT: .cfi_startproc
 ; CHECK-NEXT: .quad	i
 define void @g() prefix i32* @i {
   ret void