Implements write barrier on MIPS.

runtime/vm/constants_mips.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_CONSTANTS_MIPS_H_
 #define VM_CONSTANTS_MIPS_H_
 
 namespace dart {
 
 enum Register {
@@ skipping 143 matching lines @@
 const RegList kAllCpuRegistersList = 0xFFFFFFFF;
 
 
 const RegList kAbiArgumentCpuRegs =
     (1 << A0) | (1 << A1) | (1 << A2) | (1 << A3);
 const RegList kAbiPreservedCpuRegs =
     (1 << S0) | (1 << S1) | (1 << S2) | (1 << S3) |
     (1 << S4) | (1 << S5) | (1 << S6) | (1 << S7);
 const int kAbiPreservedCpuRegCount = 8;
 
-
 // FPU registers 20 - 31 are preserved across calls.
 const FRegister kAbiFirstPreservedFpuReg = F20;
 const FRegister kAbiLastPreservedFpuReg =
     static_cast<FRegister>(kNumberOfFRegisters - 1);
 
+// CPU registers available to Dart allocator.
+const RegList kDartAvailableCpuRegs =
+    (1 << R2) | (1 << R3) | (1 << R4) | (1 << R5) |
+    (1 << R6) | (1 << R7) | (1 << R8) | (1 << R9) |
+    (1 << R10) | (1 << R11) | (1 << R12) | (1 << R13) |
+    (1 << R14) | (1 << R15) | (1 << R16) | (1 << R17) |
+    (1 << R18) | (1 << R19) | (1 << R20) | (1 << R21);
+const RegList kDartVolatileCpuRegs =
+    kDartAvailableCpuRegs & ~kAbiPreservedCpuRegs;
+const int kDartVolatileCpuRegCount = 14;
+const Register kDartFirstVolatileCpuReg = R2;
+const Register kDartLastVolatileCpuReg = R15;
+
 // FPU registers 0 - 19 are not preserved across calls.
 const FRegister kDartFirstVolatileFpuReg = F0;
 const FRegister kDartLastVolatileFpuReg = F19;
 const int kDartVolatileFpuRegCount = 20;
 
 // Dart stack frame layout.
 static const int kLastParamSlotIndex = 3;
 static const int kFirstLocalSlotIndex = -2;
 
 
@@ skipping 301 matching lines @@
   static Instr* At(uword pc) { return reinterpret_cast<Instr*>(pc); }
 
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Instr);
 };
 
 }  // namespace dart
 
 #endif  // VM_CONSTANTS_MIPS_H_