DoubleRegister    270 src/arm/assembler-arm.h typedef DwVfpRegister DoubleRegister;
DoubleRegister    195 src/ia32/assembler-ia32.h typedef XMMRegister DoubleRegister;
DoubleRegister    281 src/mips/assembler-mips.h typedef FPURegister DoubleRegister;
DoubleRegister    283 src/x64/assembler-x64.h typedef XMMRegister DoubleRegister;