Module: Mesa Branch: main Commit: 77c0c1ce5474c6622dbaaaede21967969fee35af URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=77c0c1ce5474c6622dbaaaede21967969fee35af
Author: Ian Romanick <ian.d.roman...@intel.com> Date: Mon Sep 11 10:01:22 2023 -0700 intel/compiler: Don't create extra CFG links when deleting a block The previous is_successor_of and is_predecessor_of checks prevented creating a physical link when a logical link already existed. However, a logical link could be added when a physical link already existed. This change causes an existing physical link to be "promoted" to a logical link. Reviewed-by: Caio Oliveira <caio.olive...@intel.com> Reviewed-by: Francisco Jerez <curroje...@riseup.net> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25216> --- src/intel/compiler/brw_cfg.cpp | 50 +++++++++++++++++++++++++++++++++++------- 1 file changed, 42 insertions(+), 8 deletions(-) diff --git a/src/intel/compiler/brw_cfg.cpp b/src/intel/compiler/brw_cfg.cpp index f6d9767784c..98a58150e3c 100644 --- a/src/intel/compiler/brw_cfg.cpp +++ b/src/intel/compiler/brw_cfg.cpp @@ -450,8 +450,25 @@ cfg_t::remove_block(bblock_t *block) /* Add removed-block's successors to its predecessors' successor lists. */ foreach_list_typed (bblock_link, successor, link, &block->children) { - if (!successor->block->is_successor_of(predecessor->block, - successor->kind)) { + bool need_to_link = true; + + foreach_list_typed_safe (bblock_link, child, link, &predecessor->block->children) { + /* There is already a link between the two blocks. If the links + * are the same kind or the link is logical, do nothing. If the + * existing link is physical and the proposed new link is logical, + * promote the existing link to logical. + * + * This is accomplished by taking the minimum of the existing link + * kind and the proposed link kind. + */ + if (child->block == successor->block) { + child->kind = MIN2(child->kind, successor->kind); + need_to_link = false; + break; + } + } + + if (need_to_link) { predecessor->block->children.push_tail(link(mem_ctx, successor->block, successor->kind)); @@ -471,8 +488,25 @@ cfg_t::remove_block(bblock_t *block) /* Add removed-block's predecessors to its successors' predecessor lists. */ foreach_list_typed (bblock_link, predecessor, link, &block->parents) { - if (!predecessor->block->is_predecessor_of(successor->block, - predecessor->kind)) { + bool need_to_link = true; + + foreach_list_typed_safe (bblock_link, parent, link, &successor->block->parents) { + /* There is already a link between the two blocks. If the links + * are the same kind or the link is logical, do nothing. If the + * existing link is physical and the proposed new link is logical, + * promote the existing link to logical. + * + * This is accomplished by taking the minimum of the existing link + * kind and the proposed link kind. + */ + if (parent->block == predecessor->block) { + parent->kind = MIN2(parent->kind, predecessor->kind); + need_to_link = false; + break; + } + } + + if (need_to_link) { successor->block->parents.push_tail(link(mem_ctx, predecessor->block, predecessor->kind)); @@ -653,7 +687,7 @@ cfg_t::validate(const char *stage_abbrev) { foreach_block(block, this) { foreach_list_typed(bblock_link, successor, link, &block->children) { - /* Each successor of a block must have a predecessor link back to + /* Each successor of a block must have one predecessor link back to * the block. */ bool successor_links_back_to_predecessor = false; @@ -661,8 +695,8 @@ cfg_t::validate(const char *stage_abbrev) foreach_list_typed(bblock_link, predecessor, link, &succ_block->parents) { if (predecessor->block == block) { + cfgv_assert(!successor_links_back_to_predecessor); successor_links_back_to_predecessor = true; - break; } } @@ -670,7 +704,7 @@ cfg_t::validate(const char *stage_abbrev) } foreach_list_typed(bblock_link, predecessor, link, &block->parents) { - /* Each predecessor of a block must have a successor link back to + /* Each predecessor of a block must have one successor link back to * the block. */ bool predecessor_links_back_to_successor = false; @@ -678,8 +712,8 @@ cfg_t::validate(const char *stage_abbrev) foreach_list_typed(bblock_link, successor, link, &pred_block->children) { if (successor->block == block) { + cfgv_assert(!predecessor_links_back_to_successor); predecessor_links_back_to_successor = true; - break; } }
