From 321d41a8710e87616d72c83f07c6064e356b42ad Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Fri, 22 Jun 2012 03:04:27 +0000
Subject: [PATCH] Functions calling __builtin_eh_return must have a frame
 pointer.

The code in X86TargetLowering::LowerEH_RETURN() assumes that a frame
pointer exists, but the frame pointer was forced by the presence of
llvm.eh.unwind.init which isn't guaranteed.

If llvm.eh.unwind.init is actually required in functions calling
eh.return (is it?), we should diagnose that instead of emitting bad
machine code.

This should fix the dragonegg-x86_64-linux-gcc-4.6-test bot.

llvm-svn: 158961
---
 llvm/lib/Target/X86/X86FrameLowering.cpp      |  2 +-
 .../CodeGen/X86/2008-08-31-EH_RETURN32.ll     | 27 ++++++++++++++++---
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index c2b1cf7be2fe..a65bc15b1e45 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -52,7 +52,7 @@ bool X86FrameLowering::hasFP(const MachineFunction &MF) const {
           MFI->hasVarSizedObjects() ||
           MFI->isFrameAddressTaken() ||
           MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
-          MMI.callsUnwindInit());
+          MMI.callsUnwindInit() || MMI.callsEHReturn());
 }
 
 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
diff --git a/llvm/test/CodeGen/X86/2008-08-31-EH_RETURN32.ll b/llvm/test/CodeGen/X86/2008-08-31-EH_RETURN32.ll
index 1d27fc53ea5e..c63c890add50 100644
--- a/llvm/test/CodeGen/X86/2008-08-31-EH_RETURN32.ll
+++ b/llvm/test/CodeGen/X86/2008-08-31-EH_RETURN32.ll
@@ -1,15 +1,36 @@
 ; Check that eh_return & unwind_init were properly lowered
-; RUN: llc < %s | grep %ebp | count 9
-; RUN: llc < %s | grep %ecx | count 5
+; RUN: llc < %s -verify-machineinstrs | FileCheck %s
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64"
 target triple = "i386-pc-linux"
 
-define i8* @test(i32 %a, i8* %b)  {
+; CHECK: test1
+; CHECK: pushl %ebp
+define i8* @test1(i32 %a, i8* %b)  {
 entry:
   call void @llvm.eh.unwind.init()
   %foo   = alloca i32
   call void @llvm.eh.return.i32(i32 %a, i8* %b)
+; CHECK: movl 12(%ebp), %[[ECX:e..]]
+; CHECK: movl 8(%ebp), %[[EAX:e..]]
+; CHECK: movl %[[ECX]], 4(%ebp,%[[EAX]])
+; CHECK: leal 4(%ebp,%[[EAX]]), %[[ECX2:e..]]
+; CHECK: movl %[[ECX2]], %esp
+; CHECK: ret
+  unreachable
+}
+
+; CHECK: test2
+; CHECK: pushl %ebp
+define i8* @test2(i32 %a, i8* %b)  {
+entry:
+  call void @llvm.eh.return.i32(i32 %a, i8* %b)
+; CHECK: movl 12(%ebp), %[[ECX:e..]]
+; CHECK: movl 8(%ebp), %[[EAX:e..]]
+; CHECK: movl %[[ECX]], 4(%ebp,%[[EAX]])
+; CHECK: leal 4(%ebp,%[[EAX]]), %[[ECX2:e..]]
+; CHECK: movl %[[ECX2]], %esp
+; CHECK: ret
   unreachable
 }