Re: [PATCH v1 13/28] target/i386: use gdb_get_reg helpers

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 3/17/20 10:53 AM, Philippe Mathieu-Daudé wrote:
> On 3/16/20 6:21 PM, Alex Bennée wrote:
>> This is cleaner than poking memory directly and will make later
>> clean-ups easier.
>>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>>
>> ---
>> v7
>>    - remove stray space
>>    - fixup the floatx80 set/get routines
>> ---
>>   target/i386/gdbstub.c | 27 +++++++++++----------------
>>   1 file changed, 11 insertions(+), 16 deletions(-)
>>
>> diff --git a/target/i386/gdbstub.c b/target/i386/gdbstub.c
>> index 572ead641ca..e4d8cb66c00 100644
>> --- a/target/i386/gdbstub.c
>> +++ b/target/i386/gdbstub.c
>> @@ -98,26 +98,22 @@ int x86_cpu_gdb_read_register(CPUState *cs, 
>> uint8_t *mem_buf, int n)
>>                   return gdb_get_reg64(mem_buf,
>>                                        env->regs[gpr_map[n]] & 
>> 0xffffffffUL);
>>               } else {
>> -                memset(mem_buf, 0, sizeof(target_ulong));
>> -                return sizeof(target_ulong);
>> +                return gdb_get_regl(mem_buf, 0);
>>               }
>>           } else {
>>               return gdb_get_reg32(mem_buf, env->regs[gpr_map32[n]]);
>>           }
>>       } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
>> -#ifdef USE_X86LDOUBLE
>> -        /* FIXME: byteswap float values - after fixing fpregs layout. */
>> -        memcpy(mem_buf, &env->fpregs[n - IDX_FP_REGS], 10);
>> -#else
>> -        memset(mem_buf, 0, 10);
>> -#endif
>> -        return 10;
>> +        floatx80 *fp = (floatx80 *) &env->fpregs[n - IDX_FP_REGS];
>> +        int len = gdb_get_reg64(mem_buf, cpu_to_le64(fp->low));
>> +        len += gdb_get_reg16(mem_buf + len, cpu_to_le16(fp->high));
>> +        return len;
>>       } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
>>           n -= IDX_XMM_REGS;
>>           if (n < CPU_NB_REGS32 || TARGET_LONG_BITS == 64) {
>> -            stq_p(mem_buf, env->xmm_regs[n].ZMM_Q(0));
>> -            stq_p(mem_buf + 8, env->xmm_regs[n].ZMM_Q(1));
>> -            return 16;
>> +            return gdb_get_reg128(mem_buf,
>> +                                  env->xmm_regs[n].ZMM_Q(0),
>> +                                  env->xmm_regs[n].ZMM_Q(1));
>>           }
>>       } else {
>>           switch (n) {
>> @@ -290,10 +286,9 @@ int x86_cpu_gdb_write_register(CPUState *cs, 
>> uint8_t *mem_buf, int n)
>>               return 4;
>>           }
>>       } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
>> -#ifdef USE_X86LDOUBLE
>> -        /* FIXME: byteswap float values - after fixing fpregs layout. */
>> -        memcpy(&env->fpregs[n - IDX_FP_REGS], mem_buf, 10);
>> -#endif
>> +        floatx80 *fp = (floatx80 *) &env->fpregs[n - IDX_FP_REGS];
>> +        fp->low = le64_to_cpu(* (uint64_t *) mem_buf);
>> +        fp->high = le16_to_cpu(* (uint16_t *) (mem_buf + 8));

Note, checkpatch complains for both lines:
ERROR: space prohibited after that '*' (ctx:BxW)

>>           return 10;
>>       } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
>>           n -= IDX_XMM_REGS;
>>
> 
> I'd prefer both USE_X86LDOUBLE hunks in a separate patch, anyway:
> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>