[Mesa-dev] [PATCH] r600g: fix and optimize tgsi_cmp when using ABS and NEG modifier

[Patrick Rudolph]

It affects the game "RIFT" and fixes slightly wrong colors on
the player model, when using the nine state-tracker.

Kind Regards,
Patrick

On 2016-03-29 11:09 PM, Dave Airlie wrote:
> On 28 March 2016 at 19:52,  <siro at das-labor.org> wrote:
>> From: Patrick Rudolph <siro at das-labor.org>
>>
>> Some apps set NEG and ABS on the source param to test for zero.
>> Use ALU_OP3_CNDE insted of ALU_OP3_CNDGE and unset both modifiers.
>>
>> It also removes the need for a MOV instruction, as ABS isn't
>> supported on op3.
>>
>> Tested on AMD CAYMAN and AMD RV770.
>>
>> Signed-off-by: Patrick Rudolph <siro at das-labor.org>
> 
> Seems sane to me, does this help in any app in particular?
> 
> Reviewed-by: Dave Airlie <airlied at redhat.com>
> 
> I just have to remember to push this tomorrow.
> 
> Dave.
> 
>> ---
>>  src/gallium/drivers/r600/r600_shader.c | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
>> index 77658f5..e5e2e3f 100644
>> --- a/src/gallium/drivers/r600/r600_shader.c
>> +++ b/src/gallium/drivers/r600/r600_shader.c
>> @@ -7707,6 +7707,15 @@ static int tgsi_cmp(struct r600_shader_ctx *ctx)
>>         int i, r, j;
>>         int lasti = tgsi_last_instruction(inst->Dst[0].Register.WriteMask);
>>         int temp_regs[3];
>> +       unsigned op;
>> +
>> +       if (ctx->src[0].abs && ctx->src[0].neg) {
>> +               op = ALU_OP3_CNDE;
>> +               ctx->src[0].abs = 0;
>> +               ctx->src[0].neg = 0;
>> +       } else {
>> +               op = ALU_OP3_CNDGE;
>> +       }
>>
>>         for (j = 0; j < inst->Instruction.NumSrcRegs; j++) {
>>                 temp_regs[j] = 0;
>> @@ -7719,7 +7728,7 @@ static int tgsi_cmp(struct r600_shader_ctx *ctx)
>>                         continue;
>>
>>                 memset(&alu, 0, sizeof(struct r600_bytecode_alu));
>> -               alu.op = ALU_OP3_CNDGE;
>> +               alu.op = op;
>>                 r = tgsi_make_src_for_op3(ctx, temp_regs[0], i, &alu.src[0], &ctx->src[0]);
>>                 if (r)
>>                         return r;
>> --
>> 2.5.0
>>
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