Re: [PATCH v2 4/6] linux-user/elfload: Introduce MIPS GET_FEATURE_REG_EQU() macro

[Philippe Mathieu-Daudé]

On 12/1/20 6:36 PM, Richard Henderson wrote:
> On 12/1/20 7:35 AM, Philippe Mathieu-Daudé wrote:
>> +#define GET_FEATURE_REG_EQU(_reg, _mask, _val, _hwcap) \
>> +    do { \
>> +        if ((cpu->env._reg & (_mask)) == _val) { \
>> +            hwcaps |= _hwcap; \
>> +        } \
>> +    } while (0)
>> +
>>  static uint32_t get_elf_hwcap(void)
>>  {
>>      MIPSCPU *cpu = MIPS_CPU(thread_cpu);
>>      uint32_t hwcaps = 0;
>>  
>> -    GET_FEATURE_INSN(ISA_MIPS32R6 | ISA_MIPS64R6, HWCAP_MIPS_R6);
>> +    GET_FEATURE_REG_EQU(CP0_Config0, 7 << CP0C0_AR, 2, HWCAP_MIPS_R6);
> 
> You'd need 2 << CP0C0_AR for the equality to match.

Oops...

> Would it be better to have the shift as a separate argument?

Yes, thanks!

Phil.