From 35410a493bb393d0d8d5868feb5ef901aba64575 Mon Sep 17 00:00:00 2001
From: Anton Korobeynikov <asl@math.spbu.ru>
Date: Wed, 23 Apr 2008 18:16:43 +0000
Subject: [PATCH] Disable stack realignment for functions with dynamic-sized
 alloca's

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50155 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86RegisterInfo.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 31b9d046f67..9059a4e65e7 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -267,7 +267,10 @@ bool X86RegisterInfo::hasFP(const MachineFunction &MF) const {
 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
   MachineFrameInfo *MFI = MF.getFrameInfo();;
 
-  return (MFI->getMaxAlignment() > StackAlign);
+  // FIXME: Currently we don't support stack realignment for functions with
+  // variable-sized allocas
+  return (MFI->getMaxAlignment() > StackAlign &&
+          !MFI->hasVarSizedObjects());
 }
 
 bool X86RegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {