fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-05-05 13:58:04 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

glsl: Delete dead discard conditions in constant folding.

Browse source 
opt_constant_folding() already detects conditional assignments where the
condition is constant, and either deletes the assignment or the
condition.

Make it handle discards in the same fashion.

Spotted happening in the wild in Tropico 5 shaders.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Kenneth Graunke 2015-02-24 01:00:22 -08:00
parent d77b186871
commit 23d42b46e3
1 changed files with 24 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

24
src/glsl/opt_constant_folding.cpp
View file

@ -50,6 +50,7 @@ public:
/* empty */
}
virtual ir_visitor_status visit_enter(ir_discard *ir);
virtual ir_visitor_status visit_enter(ir_assignment *ir);
virtual ir_visitor_status visit_enter(ir_call *ir);
@ -93,6 +94,29 @@ ir_constant_folding_visitor::handle_rvalue(ir_rvalue **rvalue)
}
}
ir_visitor_status
ir_constant_folding_visitor::visit_enter(ir_discard *ir)
{
if (ir->condition) {
ir->condition->accept(this);
handle_rvalue(&ir->condition);
ir_constant *const_val = ir->condition->as_constant();
/* If the condition is constant, either remove the condition or
* remove the never-executed assignment.
*/
if (const_val) {
if (const_val->value.b[0])
ir->condition = NULL;
else
ir->remove();
this->progress = true;
}
}
return visit_continue_with_parent;
}
ir_visitor_status
ir_constant_folding_visitor::visit_enter(ir_assignment *ir)
{