From 1fdc40f0622375f7f9a4ccfbbf5deda68131f6e0 Mon Sep 17 00:00:00 2001
From: Arnold Schwaighofer <arnold.schwaighofer@gmail.com>
Date: Thu, 11 Sep 2008 20:28:43 +0000
Subject: [PATCH] When tailcallopt is enabled all fastcc calls must have an
 aligned argument stack size. Add a test case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56119 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp      |  2 +-
 test/CodeGen/X86/tailcall-stackalign.ll | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/X86/tailcall-stackalign.ll

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index ea9201ca497..010d813a41c 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1488,7 +1488,7 @@ SDValue X86TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
   
   // Get a count of how many bytes are to be pushed on the stack.
   unsigned NumBytes = CCInfo.getNextStackOffset();
-  if (IsTailCall)
+  if (PerformTailCallOpt && CC == CallingConv::Fast)
     NumBytes = GetAlignedArgumentStackSize(NumBytes, DAG);
 
   int FPDiff = 0;
diff --git a/test/CodeGen/X86/tailcall-stackalign.ll b/test/CodeGen/X86/tailcall-stackalign.ll
new file mode 100644
index 00000000000..80111925eec
--- /dev/null
+++ b/test/CodeGen/X86/tailcall-stackalign.ll
@@ -0,0 +1,24 @@
+; RUN: llvm-as < %s | llc  -mtriple=i686-unknown-linux  -tailcallopt | grep -A 1 call | grep -A 1 tailcaller | grep subl | grep 20
+; Linux has 8 byte alignment so the params cause stack size 20 when tailcallopt
+; is enabled, ensure that a normal fastcc call has matching stack size
+
+
+define fastcc i32 @tailcallee(i32 %a1, i32 %a2, i32 %a3, i32 %a4) {
+       ret i32 %a3
+}
+
+define fastcc i32 @tailcaller(i32 %in1, i32 %in2, i32 %in3, i32 %in4) {
+       %tmp11 = tail call fastcc i32 @tailcallee(i32 %in1, i32 %in2,
+                                                 i32 %in1, i32 %in2)
+       ret i32 %tmp11
+}
+
+define i32 @main(i32 %argc, i8** %argv) {
+ %tmp1 = call fastcc i32 @tailcaller( i32 1, i32 2, i32 3, i32 4 )
+ ; expect match subl [stacksize] here
+ ret i32 0
+}
+
+
+
+
-- 
2.34.1