From 0032681424a04c321fafb0e6b28ca7cd59b610f8 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Mon, 12 Oct 2009 16:36:12 +0000
Subject: [PATCH] Don't forget to mark RAX as live-out of the function when
 arranging for it to hold the address of an sret return value, for x86-64 ABI
 purposes.

Also, fix the test that was originally intended to test this to actually
test it, using FileCheck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83853 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp     |  3 +++
 test/CodeGen/X86/x86-64-sret-return.ll | 11 ++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index fb5399e4e63..fadc8183949 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1162,6 +1162,9 @@ X86TargetLowering::LowerReturn(SDValue Chain,
 
     Chain = DAG.getCopyToReg(Chain, dl, X86::RAX, Val, Flag);
     Flag = Chain.getValue(1);
+
+    // RAX now acts like a return value.
+    MF.getRegInfo().addLiveOut(X86::RAX);
   }
 
   RetOps[0] = Chain;  // Update chain.
diff --git a/test/CodeGen/X86/x86-64-sret-return.ll b/test/CodeGen/X86/x86-64-sret-return.ll
index 3ee1a0b21eb..7b5f189faa0 100644
--- a/test/CodeGen/X86/x86-64-sret-return.ll
+++ b/test/CodeGen/X86/x86-64-sret-return.ll
@@ -1,9 +1,11 @@
-; RUN: llc < %s
+; RUN: llc < %s | FileCheck %s
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
 target triple = "x86_64-apple-darwin8"
 	%struct.foo = type { [4 x i64] }
 
+; CHECK: bar:
+; CHECK: movq %rdi, %rax
 define void @bar(%struct.foo* noalias sret  %agg.result, %struct.foo* %d) nounwind  {
 entry:
 	%d_addr = alloca %struct.foo*		; <%struct.foo**> [#uses=2]
@@ -52,3 +54,10 @@ entry:
 return:		; preds = %entry
 	ret void
 }
+
+; CHECK: foo:
+; CHECK: movq %rdi, %rax
+define void @foo({ i64 }* noalias nocapture sret %agg.result) nounwind {
+  store { i64 } { i64 0 }, { i64 }* %agg.result
+  ret void
+}