From 7ffcddc1139faf53d72539b1032f60ab249875c7 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 31 Aug 2010 21:51:07 +0000
Subject: [PATCH] Make %EFLAGS unallocatable.

No CCR virtual registers should exist, and %EFLAGS is used in ways that can
surprise RegAllocFast.

llvm-svn: 112650
---
 lib/Target/X86/X86RegisterInfo.td | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/Target/X86/X86RegisterInfo.td b/lib/Target/X86/X86RegisterInfo.td
index 176e87812d2..95269b15760 100644
--- a/lib/Target/X86/X86RegisterInfo.td
+++ b/lib/Target/X86/X86RegisterInfo.td
@@ -833,4 +833,15 @@ def VR256 : RegisterClass<"X86", [v32i8, v8i32, v4i64, v8f32, v4f64], 256,
 // Status flags registers.
 def CCR : RegisterClass<"X86", [i32], 32, [EFLAGS]> {
   let CopyCost = -1;  // Don't allow copying of status registers.
+
+  // EFLAGS is not allocatable.
+  let MethodProtos = [{
+    iterator allocation_order_end(const MachineFunction &MF) const;
+  }];
+  let MethodBodies = [{
+    CCRClass::iterator
+    CCRClass::allocation_order_end(const MachineFunction &MF) const {
+      return allocation_order_begin(MF);
+    }
+  }];
 }