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

@@ -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.

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
+}