Re: [PATCH 01/12] tcg: Fix iteration step in 32-bit gvec operation

[Richard Henderson <richard.henderson@linaro.org>]

On 9/9/24 23:57, Philippe Mathieu-Daudé wrote:
> On 8/9/24 04:26, Richard Henderson wrote:
>> From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
>>
>> The loop in the 32-bit case of the vector compare operation
>> was incorrectly incrementing by 8 bytes per iteration instead
>> of 4 bytes. This caused the function to process only half of
>> the intended elements.
>>
>> Cc: qemu-stable@nongnu.org
>> Fixes: 9622c697d1 (tcg: Add gvec compare with immediate and scalar operand)
>> Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
>> Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
>> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
>> Message-ID: <20240904142739.854-2-zhiwei_liu@linux.alibaba.com>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   tcg/tcg-op-gvec.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tcg/tcg-op-gvec.c b/tcg/tcg-op-gvec.c
>> index 0308732d9b..78ee1ced80 100644
>> --- a/tcg/tcg-op-gvec.c
>> +++ b/tcg/tcg-op-gvec.c
>> @@ -3939,7 +3939,7 @@ void tcg_gen_gvec_cmps(TCGCond cond, unsigned vece, uint32_t dofs,
>>           uint32_t i;
>>           tcg_gen_extrl_i64_i32(t1, c);
>> -        for (i = 0; i < oprsz; i += 8) {
>> +        for (i = 0; i < oprsz; i += 4) {
> 
> Maybe using memop_size(vece) would have been safer to avoid copy/paste bugs?

No, vece can be smaller than 4 here.

r~

> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> 
>>               tcg_gen_ld_i32(t0, tcg_env, aofs + i);
>>               tcg_gen_negsetcond_i32(cond, t0, t0, t1);
>>               tcg_gen_st_i32(t0, tcg_env, dofs + i);
>