From 5a0fabae5a1792d20df23b6cbd573a9121637d12 Mon Sep 17 00:00:00 2001
From: Jim Grosbach <grosbach@apple.com>
Date: Thu, 2 Sep 2010 16:31:21 +0000
Subject: [PATCH] Mask out reserved registers when constructing the set of
 allocatable regs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112828 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/TargetRegisterInfo.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/Target/TargetRegisterInfo.cpp b/lib/Target/TargetRegisterInfo.cpp
index 49bfad54136..cdbe51fbdd9 100644
--- a/lib/Target/TargetRegisterInfo.cpp
+++ b/lib/Target/TargetRegisterInfo.cpp
@@ -80,6 +80,11 @@ BitVector TargetRegisterInfo::getAllocatableSet(const MachineFunction &MF,
   for (TargetRegisterInfo::regclass_iterator I = regclass_begin(),
          E = regclass_end(); I != E; ++I)
     getAllocatableSetForRC(MF, *I, Allocatable);
+
+  // Mask out the reserved registers
+  BitVector Reserved = getReservedRegs(MF);
+  Allocatable ^= Reserved & Allocatable;
+
   return Allocatable;
 }