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 <[email protected]>
Tag for stable branches?
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