Re: [Mesa-dev] [PATCH] state_tracker: Fix bug in conditional discards with native ints.

2014-09-04 Thread Eric Anholt 
Brian Paul  writes:

> On 09/03/2014 03:04 PM, Eric Anholt wrote:
>> A bool is 0 or ~0, and KILL_IF takes a float arg that's <0 for discard or
>>> = 0 for not.  By negating it, we ended up doing a floating point subtract
>> of (0 - ~0), which ended up as an inf.  To make this actually work, we
>> need to convert the bool to a float.
>> ---
>>   src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 14 --
>>   1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp 
>> b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> index dd9c84f..62e4101 100644
>> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>> @@ -3091,8 +3091,18 @@ glsl_to_tgsi_visitor::visit(ir_discard *ir)
>>   {
>>  if (ir->condition) {
>> ir->condition->accept(this);
>> -  this->result.negate = ~this->result.negate;
>> -  emit(ir, TGSI_OPCODE_KILL_IF, undef_dst, this->result);
>> +  st_src_reg condition = this->result;
>> +
>> +  /* Convert the bool condition to a float so we can negate. */
>> +  if (native_integers) {
>> + st_src_reg temp = get_temp(ir->condition->type);
>> + emit(ir, TGSI_OPCODE_AND, st_dst_reg(temp),
>> +  condition, st_src_reg_for_float(1.0));
>> + condition = temp;
>> +  }
>> +
>> +  condition.negate = ~condition.negate;
>> +  emit(ir, TGSI_OPCODE_KILL_IF, undef_dst, condition);
>>  } else {
>> /* unconditional kil */
>> emit(ir, TGSI_OPCODE_KILL);
>>
>
> Reviewed-by: Brian Paul 
>
> Tag for stable branches?

I don't think there are any releaseable drivers doing native ints
without control flow in the stable braches -- GLSL discards just don't
work at all if you're hitting this bug.


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Re: [Mesa-dev] [PATCH] state_tracker: Fix bug in conditional discards with native ints.

2014-09-04 Thread Brian Paul 

On 09/03/2014 03:04 PM, Eric Anholt wrote:

A bool is 0 or ~0, and KILL_IF takes a float arg that's <0 for discard or

= 0 for not.  By negating it, we ended up doing a floating point subtract

of (0 - ~0), which ended up as an inf.  To make this actually work, we
need to convert the bool to a float.
---
  src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 14 --
  1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp 
b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index dd9c84f..62e4101 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -3091,8 +3091,18 @@ glsl_to_tgsi_visitor::visit(ir_discard *ir)
  {
 if (ir->condition) {
ir->condition->accept(this);
-  this->result.negate = ~this->result.negate;
-  emit(ir, TGSI_OPCODE_KILL_IF, undef_dst, this->result);
+  st_src_reg condition = this->result;
+
+  /* Convert the bool condition to a float so we can negate. */
+  if (native_integers) {
+ st_src_reg temp = get_temp(ir->condition->type);
+ emit(ir, TGSI_OPCODE_AND, st_dst_reg(temp),
+  condition, st_src_reg_for_float(1.0));
+ condition = temp;
+  }
+
+  condition.negate = ~condition.negate;
+  emit(ir, TGSI_OPCODE_KILL_IF, undef_dst, condition);
 } else {
/* unconditional kil */
emit(ir, TGSI_OPCODE_KILL);



Reviewed-by: Brian Paul 

Tag for stable branches?

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[Mesa-dev] [PATCH] state_tracker: Fix bug in conditional discards with native ints.

2014-09-03 Thread Eric Anholt 
A bool is 0 or ~0, and KILL_IF takes a float arg that's <0 for discard or
>= 0 for not.  By negating it, we ended up doing a floating point subtract
of (0 - ~0), which ended up as an inf.  To make this actually work, we
need to convert the bool to a float.
---
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 14 --
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp 
b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index dd9c84f..62e4101 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -3091,8 +3091,18 @@ glsl_to_tgsi_visitor::visit(ir_discard *ir)
 {
if (ir->condition) {
   ir->condition->accept(this);
-  this->result.negate = ~this->result.negate;
-  emit(ir, TGSI_OPCODE_KILL_IF, undef_dst, this->result);
+  st_src_reg condition = this->result;
+
+  /* Convert the bool condition to a float so we can negate. */
+  if (native_integers) {
+ st_src_reg temp = get_temp(ir->condition->type);
+ emit(ir, TGSI_OPCODE_AND, st_dst_reg(temp),
+  condition, st_src_reg_for_float(1.0));
+ condition = temp;
+  }
+
+  condition.negate = ~condition.negate;
+  emit(ir, TGSI_OPCODE_KILL_IF, undef_dst, condition);
} else {
   /* unconditional kil */
   emit(ir, TGSI_OPCODE_KILL);
-- 
2.1.0

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