Giovanni Mascellani : vkd3d-shader/ir: Fixup PHI nodes when lowering switches to selection ladders.
Module: vkd3d Branch: master Commit: 026c502f31cfcdaf2679e1ece74766598916e9c1 URL: https://gitlab.winehq.org/wine/vkd3d/-/commit/026c502f31cfcdaf2679e1ece74766... Author: Giovanni Mascellani <gmascellani(a)codeweavers.com> Date: Mon Jan 15 17:02:07 2024 +0100 vkd3d-shader/ir: Fixup PHI nodes when lowering switches to selection ladders. A map between the blocks before and after the pass is built and then used to fix the PHI nodes. --- libs/vkd3d-shader/ir.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 149 insertions(+), 9 deletions(-) diff --git a/libs/vkd3d-shader/ir.c b/libs/vkd3d-shader/ir.c index c2568316..1bb35fd7 100644 --- a/libs/vkd3d-shader/ir.c +++ b/libs/vkd3d-shader/ir.c @@ -2388,15 +2388,47 @@ static bool reserve_instructions(struct vkd3d_shader_instruction **instructions, return true; } +/* A record represents replacing a jump from block `switch_label' to + * block `target_label' with a jump from block `if_label' to block + * `target_label'. */ +struct lower_switch_to_if_ladder_block_mapping +{ + unsigned int switch_label; + unsigned int if_label; + unsigned int target_label; +}; + +static bool lower_switch_to_if_ladder_add_block_mapping(struct lower_switch_to_if_ladder_block_mapping **block_map, + size_t *map_capacity, size_t *map_count, unsigned int switch_label, unsigned int if_label, unsigned int target_label) +{ + if (!vkd3d_array_reserve((void **)block_map, map_capacity, *map_count + 1, sizeof(**block_map))) + { + ERR("Failed to allocate block mapping.\n"); + return false; + } + + (*block_map)[*map_count].switch_label = switch_label; + (*block_map)[*map_count].if_label = if_label; + (*block_map)[*map_count].target_label = target_label; + + *map_count += 1; + + return true; +} + static enum vkd3d_result lower_switch_to_if_ladder(struct vkd3d_shader_parser *parser) { - unsigned int block_count = parser->program.block_count, ssa_count = parser->program.ssa_count; + unsigned int block_count = parser->program.block_count, ssa_count = parser->program.ssa_count, current_label = 0, if_label; + size_t ins_capacity = 0, ins_count = 0, i, map_capacity = 0, map_count = 0; struct vkd3d_shader_instruction *instructions = NULL; - size_t ins_capacity = 0, ins_count = 0, i; + struct lower_switch_to_if_ladder_block_mapping *block_map = NULL; if (!reserve_instructions(&instructions, &ins_capacity, parser->program.instructions.count)) goto fail; + /* First subpass: convert SWITCH_MONOLITHIC instructions to + * selection ladders, keeping a map between blocks before and + * after the subpass. */ for (i = 0; i < parser->program.instructions.count; ++i) { struct vkd3d_shader_instruction *ins = &parser->program.instructions.elements[i]; @@ -2404,15 +2436,16 @@ static enum vkd3d_result lower_switch_to_if_ladder(struct vkd3d_shader_parser *p switch (ins->handler_idx) { + case VKD3DSIH_LABEL: + current_label = label_from_src_param(&ins->src[0]); + if (!reserve_instructions(&instructions, &ins_capacity, ins_count + 1)) + goto fail; + instructions[ins_count++] = *ins; + continue; + case VKD3DSIH_SWITCH_MONOLITHIC: break; - case VKD3DSIH_PHI: - WARN("Unhandled PHI when lowering switch.\n"); - vkd3d_shader_parser_error(parser, VKD3D_SHADER_ERROR_VSIR_NOT_IMPLEMENTED, - "Unhandled PHI when lowering switch."); - return VKD3D_ERROR_NOT_IMPLEMENTED; - default: if (!reserve_instructions(&instructions, &ins_capacity, ins_count + 1)) goto fail; @@ -2439,6 +2472,8 @@ static enum vkd3d_result lower_switch_to_if_ladder(struct vkd3d_shader_parser *p if (!reserve_instructions(&instructions, &ins_capacity, ins_count + 3 * case_count - 1)) goto fail; + if_label = current_label; + for (j = 0; j < case_count; ++j) { unsigned int fallthrough_label, case_label = label_from_src_param(&ins->src[3 + 2 * j + 1]); @@ -2467,17 +2502,121 @@ static enum vkd3d_result lower_switch_to_if_ladder(struct vkd3d_shader_parser *p ++ssa_count; - if (j != case_count - 1) + if (!lower_switch_to_if_ladder_add_block_mapping(&block_map, &map_capacity, &map_count, + current_label, if_label, case_label)) + goto fail; + + if (j == case_count - 1) + { + if (!lower_switch_to_if_ladder_add_block_mapping(&block_map, &map_capacity, &map_count, + current_label, if_label, default_label)) + goto fail; + } + else { if (!vsir_instruction_init_with_params(parser, &instructions[ins_count], &ins->location, VKD3DSIH_LABEL, 0, 1)) goto fail; vsir_src_param_init_label(&instructions[ins_count].src[0], ++block_count); ++ins_count; + + if_label = block_count; } } } + /* Second subpass: creating new blocks might have broken + * references in PHI instructions, so we use the block map to fix + * them. */ + current_label = 0; + for (i = 0; i < ins_count; ++i) + { + struct vkd3d_shader_instruction *ins = &instructions[i]; + struct vkd3d_shader_src_param *new_src; + unsigned int j, l, new_src_count = 0; + + switch (ins->handler_idx) + { + case VKD3DSIH_LABEL: + current_label = label_from_src_param(&ins->src[0]); + continue; + + case VKD3DSIH_PHI: + break; + + default: + continue; + } + + /* First count how many source parameters we need. */ + for (j = 0; j < ins->src_count; j += 2) + { + unsigned int source_label = label_from_src_param(&ins->src[j + 1]); + size_t k, match_count = 0; + + for (k = 0; k < map_count; ++k) + { + struct lower_switch_to_if_ladder_block_mapping *mapping = &block_map[k]; + + if (mapping->switch_label == source_label && mapping->target_label == current_label) + match_count += 1; + } + + new_src_count += (match_count != 0) ? 2 * match_count : 2; + } + + assert(new_src_count >= ins->src_count); + + /* Allocate more source parameters if needed. */ + if (new_src_count == ins->src_count) + { + new_src = ins->src; + } + else + { + if (!(new_src = shader_parser_get_src_params(parser, new_src_count))) + { + ERR("Failed to allocate %u source parameters.\n", new_src_count); + goto fail; + } + } + + /* Then do the copy. */ + for (j = 0, l = 0; j < ins->src_count; j += 2) + { + unsigned int source_label = label_from_src_param(&ins->src[j + 1]); + size_t k, match_count = 0; + + for (k = 0; k < map_count; ++k) + { + struct lower_switch_to_if_ladder_block_mapping *mapping = &block_map[k]; + + if (mapping->switch_label == source_label && mapping->target_label == current_label) + { + match_count += 1; + + new_src[l] = ins->src[j]; + new_src[l + 1] = ins->src[j + 1]; + new_src[l + 1].reg.idx[0].offset = mapping->if_label; + l += 2; + } + } + + if (match_count == 0) + { + new_src[l] = ins->src[j]; + new_src[l + 1] = ins->src[j + 1]; + l += 2; + } + } + + assert(l == new_src_count); + + ins->src_count = new_src_count; + ins->src = new_src; + } + vkd3d_free(parser->program.instructions.elements); + vkd3d_free(block_map); parser->program.instructions.elements = instructions; parser->program.instructions.capacity = ins_capacity; parser->program.instructions.count = ins_count; @@ -2488,6 +2627,7 @@ static enum vkd3d_result lower_switch_to_if_ladder(struct vkd3d_shader_parser *p fail: vkd3d_free(instructions); + vkd3d_free(block_map); return VKD3D_ERROR_OUT_OF_MEMORY; }
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Alexandre Julliard