Out-of-line constant pool on Arm: Stage 1 - Free up r7 for use as constant pool pointer register

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 100 matching lines @@
 // doing certain constant folds, which may significantly reduce the
 // code generated for some assembly instructions (because they boil down
 // to a few constants). If this is a problem, we could change the code
 // such that we use an enum in optimized mode, and the struct in debug
 // mode. This way we get the compile-time error checking in debug mode
 // and best performance in optimized code.
 
 // Core register
 struct Register {
   static const int kNumRegisters = 16;
-  static const int kMaxNumAllocatableRegisters = 8;
+  static const int kMaxNumAllocatableRegisters =
+      FLAG_enable_ool_constant_pool ? 7 : 8;
   static const int kSizeInBytes = 4;
 
   inline static int NumAllocatableRegisters();
 
   static int ToAllocationIndex(Register reg) {
     ASSERT(reg.code() < kMaxNumAllocatableRegisters);
     return reg.code();
   }
 
   static Register FromAllocationIndex(int index) {
@@ skipping 62 matching lines @@
 
 const Register no_reg = { kRegister_no_reg_Code };
 
 const Register r0  = { kRegister_r0_Code };
 const Register r1  = { kRegister_r1_Code };
 const Register r2  = { kRegister_r2_Code };
 const Register r3  = { kRegister_r3_Code };
 const Register r4  = { kRegister_r4_Code };
 const Register r5  = { kRegister_r5_Code };
 const Register r6  = { kRegister_r6_Code };
+// Used as constant pool pointer register if FLAGS_enable_ool_constant_pool.
 const Register r7  = { kRegister_r7_Code };
 // Used as context register.
 const Register r8  = { kRegister_r8_Code };
 // Used as lithium codegen scratch register.
 const Register r9  = { kRegister_r9_Code };
 // Used as roots register.
 const Register r10 = { kRegister_r10_Code };
 const Register fp  = { kRegister_fp_Code };
 const Register ip  = { kRegister_ip_Code };
 const Register sp  = { kRegister_sp_Code };
@@ skipping 1362 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_