[Mesa-dev] [PATCH] mesa, glsl_to_tgsi: fixes for native integers

[Ian Romanick]

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On 08/29/2011 09:31 AM, Eric Anholt wrote:
> On Fri, 26 Aug 2011 21:58:12 -0500, Bryan Cain <bryancain3 at gmail.com> wrote:
>> This fixes all of the piglit regressions in softpipe when native integers are
>> enabled.
>> ---
>>  src/mesa/main/uniforms.c                   |    8 +----
>>  src/mesa/state_tracker/st_glsl_to_tgsi.cpp |   45 ++++++++++++++++++++++++++--
>>  2 files changed, 43 insertions(+), 10 deletions(-)
>>
>> diff --git a/src/mesa/main/uniforms.c b/src/mesa/main/uniforms.c
>> index cda840f..0801476 100644
>> --- a/src/mesa/main/uniforms.c
>> +++ b/src/mesa/main/uniforms.c
>> @@ -776,13 +776,7 @@ set_program_uniform(struct gl_context *ctx, struct gl_program *program,
>>           /* if the uniform is bool-valued, convert to 1 or 0 */
>>           if (isUniformBool) {
>>              for (i = 0; i < elems; i++) {
>> -               if (basicType == GL_FLOAT)
>> -                  uniformVal[i].b = uniformVal[i].f != 0.0f ? 1 : 0;
>> -               else
>> -                  uniformVal[i].b = uniformVal[i].u ? 1 : 0;
>> -               
>> -               if (!ctx->Const.NativeIntegers)
>> -                  uniformVal[i].f = uniformVal[i].b ? 1.0f : 0.0f;
>> +               uniformVal[i].f = uniformVal[i].f != 0.0f ? 1.0f : 0.0f;
>>              }
>>           }
>>        }
> 
> I think booleans should be integer 1 as uniforms.  Otherwise I'll need a
> RealNativeIntegers flag to get that behavior.

I think the issue they're running into is that all non-Intel hardware
uses ~0 for true (out of the "set" instructions) and 0 for false when
using integers.  Most of the rest of the stack expects 1 and 0, so the
impedance mismatch is causing headaches.  The (1-b) implementation of
ir_unop_not stops working, for example.  Though, in that case it seems
like you should have (and use) an integer bit-wise not instruction.

It seems like there should be a better way to handle this...
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