From 5bfb3027834602841a62907929bb7795068fd44e Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Wed, 24 Feb 2016 19:39:49 -0800 Subject: [PATCH] i965/cfg: Split out dead control flow paths to simplify both paths v2: Fix some bad indentation. Suggested by Curro. Signed-off-by: Ian Romanick Reviewed-by: Francisco Jerez --- .../dri/i965/brw_dead_control_flow.cpp | 93 ++++++++----------- 1 file changed, 38 insertions(+), 55 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp index 856357239a4..345149287ed 100644 --- a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp +++ b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp @@ -48,67 +48,50 @@ dead_control_flow_eliminate(backend_shader *s) /* ENDIF instructions, by definition, can only be found at the start of * basic blocks. */ - if (inst->opcode == BRW_OPCODE_ENDIF) { - bool found = false; - bblock_t *if_block = NULL, *else_block = NULL, *endif_block = block; - backend_instruction *endif_inst = inst; - - backend_instruction *if_inst = NULL, *else_inst = NULL; - if (prev_inst->opcode == BRW_OPCODE_ELSE) { - else_inst = prev_inst; - else_block = endif_block->prev(); - found = true; - - /* Don't remove the ENDIF if we didn't find a dead IF. */ - endif_inst = NULL; - } - - if (prev_inst->opcode == BRW_OPCODE_IF) { - if_inst = prev_inst; - if_block = prev_block; - found = true; - } - - if (found) { - bblock_t *earlier_block = NULL, *later_block = NULL; + if (inst->opcode == BRW_OPCODE_ENDIF && + prev_inst->opcode == BRW_OPCODE_ELSE) { + bblock_t *const else_block = prev_block; + backend_instruction *const else_inst = prev_inst; - if (if_inst) { - if (if_block->start_ip == if_block->end_ip) { - earlier_block = if_block->prev(); - } else { - earlier_block = if_block; - } - if_inst->remove(if_block); - } + else_inst->remove(else_block); + progress = true; + } else if (inst->opcode == BRW_OPCODE_ENDIF && + prev_inst->opcode == BRW_OPCODE_IF) { + bblock_t *const endif_block = block; + bblock_t *const if_block = prev_block; + backend_instruction *const endif_inst = inst; + backend_instruction *const if_inst = prev_inst; - if (else_inst) { - else_inst->remove(else_block); - } + bblock_t *earlier_block = NULL, *later_block = NULL; - if (endif_inst) { - if (endif_block->start_ip == endif_block->end_ip) { - later_block = endif_block->next(); - } else { - later_block = endif_block; - } - endif_inst->remove(endif_block); - } + if (if_block->start_ip == if_block->end_ip) { + earlier_block = if_block->prev(); + } else { + earlier_block = if_block; + } + if_inst->remove(if_block); - assert((earlier_block == NULL) == (later_block == NULL)); - if (earlier_block && earlier_block->can_combine_with(later_block)) { - earlier_block->combine_with(later_block); - - /* If ENDIF was in its own block, then we've now deleted it and - * merged the two surrounding blocks, the latter of which the - * __next block pointer was pointing to. - */ - if (endif_block != later_block) { - __next = earlier_block->next(); - } + if (endif_block->start_ip == endif_block->end_ip) { + later_block = endif_block->next(); + } else { + later_block = endif_block; + } + endif_inst->remove(endif_block); + + assert((earlier_block == NULL) == (later_block == NULL)); + if (earlier_block && earlier_block->can_combine_with(later_block)) { + earlier_block->combine_with(later_block); + + /* If ENDIF was in its own block, then we've now deleted it and + * merged the two surrounding blocks, the latter of which the + * __next block pointer was pointing to. + */ + if (endif_block != later_block) { + __next = earlier_block->next(); } - - progress = true; } + + progress = true; } else if (inst->opcode == BRW_OPCODE_ELSE && prev_inst->opcode == BRW_OPCODE_IF) { bblock_t *const else_block = block; -- 2.30.2