From 2d44e02533cdc2ae011121ef651dda93769ced2b Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 3 Jan 2012 22:34:31 +0000
Subject: [PATCH] Assert when reserved registers have been assigned.

This can only happen if the set of reserved registers changes during
register allocation.

<rdar://problem/10625436>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147486 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/VirtRegMap.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 1a78db7107f..35834aa205c 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -112,6 +112,9 @@ void VirtRegMap::rewrite(SlotIndexes *Indexes) {
   SmallVector<unsigned, 8> SuperDeads;
   SmallVector<unsigned, 8> SuperDefs;
   SmallVector<unsigned, 8> SuperKills;
+#ifndef NDEBUG
+  BitVector Reserved = TRI->getReservedRegs(*MF);
+#endif
 
   for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
        MBBI != MBBE; ++MBBI) {
@@ -129,6 +132,7 @@ void VirtRegMap::rewrite(SlotIndexes *Indexes) {
         unsigned VirtReg = MO.getReg();
         unsigned PhysReg = getPhys(VirtReg);
         assert(PhysReg != NO_PHYS_REG && "Instruction uses unmapped VirtReg");
+        assert(!Reserved.test(PhysReg) && "Reserved register assignment");
 
         // Preserve semantics of sub-register operands.
         if (MO.getSubReg()) {