Fix a fastcc + sret bug. If fastcc and sret, callee doesn't need to pop the hidden struct ptr; Re-enable fastcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56061 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/sret.ll b/test/CodeGen/X86/sret.ll
new file mode 100644
index 0000000..30e5af4
--- /dev/null
+++ b/test/CodeGen/X86/sret.ll
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep ret | grep 4
+
+	%struct.foo = type { [4 x i32] }
+
+define void @bar(%struct.foo* noalias sret %agg.result) nounwind  {
+entry:
+	%tmp1 = getelementptr %struct.foo* %agg.result, i32 0, i32 0
+	%tmp3 = getelementptr [4 x i32]* %tmp1, i32 0, i32 0
+	store i32 1, i32* %tmp3, align 8
+        ret void
+}
+
+@dst = external global i32
+
+define void @foo() nounwind {
+	%memtmp = alloca %struct.foo, align 4
+        call void @bar( %struct.foo* sret %memtmp ) nounwind
+        %tmp4 = getelementptr %struct.foo* %memtmp, i32 0, i32 0
+	%tmp5 = getelementptr [4 x i32]* %tmp4, i32 0, i32 0
+        %tmp6 = load i32* %tmp5
+        store i32 %tmp6, i32* @dst
+        ret void
+}