diff options
Diffstat (limited to 'src/mesa/drivers/dri')
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp b/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp index 31b287aae36..b7a1d7e7722 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp @@ -38,6 +38,18 @@ * * This peephole pass removes the IF and ENDIF instructions and predicates the * BREAK, dropping two instructions from the loop body. + * + * If the loop was a DO { ... } WHILE loop, it looks like + * + * loop: + * ... + * CMP.f0 + * (+f0) IF + * BREAK + * ENDIF + * WHILE loop + * + * and we can remove the BREAK instruction and predicate the WHILE. */ bool @@ -107,6 +119,30 @@ fs_visitor::opt_peephole_predicated_break() block = earlier_block; } + /* Now look at the first instruction of the block following the BREAK. If + * it's a WHILE, we can delete the break, predicate the WHILE, and join + * the two basic blocks. + */ + bblock_t *while_block = earlier_block->next(); + fs_inst *while_inst = (fs_inst *)while_block->start(); + + if (jump_inst->opcode == BRW_OPCODE_BREAK && + while_inst->opcode == BRW_OPCODE_WHILE && + while_inst->predicate == BRW_PREDICATE_NONE) { + jump_inst->remove(earlier_block); + while_inst->predicate = jump_inst->predicate; + while_inst->predicate_inverse = !jump_inst->predicate_inverse; + + earlier_block->children.make_empty(); + earlier_block->add_successor(cfg->mem_ctx, while_block); + + assert(earlier_block->can_combine_with(while_block)); + earlier_block->combine_with(while_block); + + earlier_block->next()->parents.make_empty(); + earlier_block->add_successor(cfg->mem_ctx, earlier_block->next()); + } + progress = true; } |