[Mesa-dev] [PATCH mesa] radv: s/abs/fabsf/ for floats

[Roland Scheidegger]

Am 18.10.18 um 19:25 schrieb Matt Turner:
> On Thu, Oct 18, 2018 at 8:46 AM Eric Engestrom <eric.engestrom at intel.com> wrote:
>>
>> Fixes: a4c4efad89eceb26cf82 "radv: Rework guard band calculation"
>> Cc: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
>> Signed-off-by: Eric Engestrom <eric.engestrom at intel.com>
>> ---
>>  src/amd/vulkan/si_cmd_buffer.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/src/amd/vulkan/si_cmd_buffer.c b/src/amd/vulkan/si_cmd_buffer.c
>> index de057657ee70d354e910..52daf99414790d4764b6 100644
>> --- a/src/amd/vulkan/si_cmd_buffer.c
>> +++ b/src/amd/vulkan/si_cmd_buffer.c
>> @@ -516,16 +516,16 @@ si_write_scissors(struct radeon_cmdbuf *cs, int first,
>>                 VkRect2D scissor = si_intersect_scissor(&scissors[i], &viewport_scissor);
>>
>>                 get_viewport_xform(viewports + i, scale, translate);
>> -               scale[0] = abs(scale[0]);
>> -               scale[1] = abs(scale[1]);
>> +               scale[0] = fabsf(scale[0]);
>> +               scale[1] = fabsf(scale[1]);
>>
>>                 if (scale[0] < 0.5)
> 
> You might want to suffix these immediates with f at the same time. As
> is, this will convert scale[0] to a double before the compairson
> against 0.5. I'm assuming that scale[0] is a float, which I've
> inferred from the patch but haven't confirmed.

Not that I don't think doing this isn't good idea, but I think compilers
are clever enough to figure this out and omit the conversion? At least
if you don't compile with -O0...

Roland