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25 * \file opt_conditional_discard.cpp
33 * (discard <condition>)
36 #include "glsl_types.h"
41 class opt_conditional_discard_visitor
: public ir_hierarchical_visitor
{
43 opt_conditional_discard_visitor()
48 ir_visitor_status
visit_leave(ir_if
*);
53 } /* anonymous namespace */
56 opt_conditional_discard(exec_list
*instructions
)
58 opt_conditional_discard_visitor v
;
64 opt_conditional_discard_visitor::visit_leave(ir_if
*ir
)
66 /* Look for "if (...) discard" with no else clause or extra statements. */
67 if (ir
->then_instructions
.is_empty() ||
68 !ir
->then_instructions
.head
->next
->is_tail_sentinel() ||
69 !((ir_instruction
*) ir
->then_instructions
.head
)->as_discard() ||
70 !ir
->else_instructions
.is_empty())
71 return visit_continue
;
73 /* Move the condition and replace the ir_if with the ir_discard. */
74 ir_discard
*discard
= (ir_discard
*) ir
->then_instructions
.head
;
75 discard
->condition
= ir
->condition
;
76 ir
->replace_with(discard
);
80 return visit_continue
;