Set a fixed scratch register for ARM code generation...

src/arm/assembler-arm.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 114 matching lines @@
 
 const Register r0  = {  0 };
 const Register r1  = {  1 };
 const Register r2  = {  2 };
 const Register r3  = {  3 };
 const Register r4  = {  4 };
 const Register r5  = {  5 };
 const Register r6  = {  6 };
 const Register r7  = {  7 };
 const Register r8  = {  8 };  // Used as context register.
-const Register r9  = {  9 };
+const Register r9  = {  9 };  // Used as lithium codegen scratch register.

[Karl Klose, 2011/01/04 14:25:28]

Perhaps add a STATIC_ASSERT(kNumAllocatableRegisters <= 8) somewhere?

[Søren Thygesen Gjesse, 2011/01/04 14:32:40]

Added an assert to the ToAllocationIndex to assert that only registers r0 - r7
are allocated.

 const Register r10 = { 10 };  // Used as roots register.
 const Register fp  = { 11 };
 const Register ip  = { 12 };
 const Register sp  = { 13 };
 const Register lr  = { 14 };
 const Register pc  = { 15 };
 
 // Single word VFP register.
 struct SwVfpRegister {
   bool is_valid() const { return 0 <= code_ && code_ < 32; }
@@ skipping 1265 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_