/* * Copyright (C) 2019 Alyssa Rosenzweig * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #ifndef _MDG_COMPILER_H #define _MDG_COMPILER_H #include "midgard.h" #include "helpers.h" #include "midgard_compile.h" #include "util/hash_table.h" #include "util/u_dynarray.h" #include "util/set.h" #include "util/list.h" #include "main/mtypes.h" #include "compiler/nir_types.h" #include "compiler/nir/nir.h" /* Forward declare */ struct midgard_block; /* Target types. Defaults to TARGET_GOTO (the type corresponding directly to * the hardware), hence why that must be zero. TARGET_DISCARD signals this * instruction is actually a discard op. */ #define TARGET_GOTO 0 #define TARGET_BREAK 1 #define TARGET_CONTINUE 2 #define TARGET_DISCARD 3 typedef struct midgard_branch { /* If conditional, the condition is specified in r31.w */ bool conditional; /* For conditionals, if this is true, we branch on FALSE. If false, we branch on TRUE. */ bool invert_conditional; /* Branch targets: the start of a block, the start of a loop (continue), the end of a loop (break). Value is one of TARGET_ */ unsigned target_type; /* The actual target */ union { int target_block; int target_break; int target_continue; }; } midgard_branch; /* Instruction arguments represented as block-local SSA indices, rather than * registers. Negative values mean unused. */ typedef struct { int src0; int src1; int dest; /* src1 is -not- SSA but instead a 16-bit inline constant to be smudged * in. Only valid for ALU ops. */ bool inline_constant; } ssa_args; /* Generic in-memory data type repesenting a single logical instruction, rather * than a single instruction group. This is the preferred form for code gen. * Multiple midgard_insturctions will later be combined during scheduling, * though this is not represented in this structure. Its format bridges * the low-level binary representation with the higher level semantic meaning. * * Notably, it allows registers to be specified as block local SSA, for code * emitted before the register allocation pass. */ typedef struct midgard_instruction { /* Must be first for casting */ struct list_head link; unsigned type; /* ALU, load/store, texture */ /* If the register allocator has not run yet... */ ssa_args ssa_args; /* Special fields for an ALU instruction */ midgard_reg_info registers; /* I.e. (1 << alu_bit) */ int unit; /* When emitting bundle, should this instruction have a break forced * before it? Used for r31 writes which are valid only within a single * bundle and *need* to happen as early as possible... this is a hack, * TODO remove when we have a scheduler */ bool precede_break; bool has_constants; float constants[4]; uint16_t inline_constant; bool has_blend_constant; bool compact_branch; bool writeout; bool prepacked_branch; union { midgard_load_store_word load_store; midgard_vector_alu alu; midgard_texture_word texture; midgard_branch_extended branch_extended; uint16_t br_compact; /* General branch, rather than packed br_compact. Higher level * than the other components */ midgard_branch branch; }; } midgard_instruction; typedef struct midgard_block { /* Link to next block. Must be first for mir_get_block */ struct list_head link; /* List of midgard_instructions emitted for the current block */ struct list_head instructions; bool is_scheduled; /* List of midgard_bundles emitted (after the scheduler has run) */ struct util_dynarray bundles; /* Number of quadwords _actually_ emitted, as determined after scheduling */ unsigned quadword_count; /* Successors: always one forward (the block after us), maybe * one backwards (for a backward branch). No need for a second * forward, since graph traversal would get there eventually * anyway */ struct midgard_block *successors[2]; unsigned nr_successors; /* The successors pointer form a graph, and in the case of * complex control flow, this graph has a cycles. To aid * traversal during liveness analysis, we have a visited? * boolean for passes to use as they see fit, provided they * clean up later */ bool visited; } midgard_block; typedef struct midgard_bundle { /* Tag for the overall bundle */ int tag; /* Instructions contained by the bundle */ int instruction_count; midgard_instruction *instructions[5]; /* Bundle-wide ALU configuration */ int padding; int control; bool has_embedded_constants; float constants[4]; bool has_blend_constant; } midgard_bundle; typedef struct compiler_context { nir_shader *nir; gl_shader_stage stage; /* Is internally a blend shader? Depends on stage == FRAGMENT */ bool is_blend; /* Tracking for blend constant patching */ int blend_constant_offset; /* Current NIR function */ nir_function *func; /* Unordered list of midgard_blocks */ int block_count; struct list_head blocks; midgard_block *initial_block; midgard_block *previous_source_block; midgard_block *final_block; /* List of midgard_instructions emitted for the current block */ midgard_block *current_block; /* The current "depth" of the loop, for disambiguating breaks/continues * when using nested loops */ int current_loop_depth; /* Constants which have been loaded, for later inlining */ struct hash_table_u64 *ssa_constants; /* SSA values / registers which have been aliased. Naively, these * demand a fmov output; instead, we alias them in a later pass to * avoid the wasted op. * * A note on encoding: to avoid dynamic memory management here, rather * than ampping to a pointer, we map to the source index; the key * itself is just the destination index. */ struct hash_table_u64 *ssa_to_alias; struct set *leftover_ssa_to_alias; /* Actual SSA-to-register for RA */ struct hash_table_u64 *ssa_to_register; /* Mapping of hashes computed from NIR indices to the sequential temp indices ultimately used in MIR */ struct hash_table_u64 *hash_to_temp; int temp_count; int max_hash; /* Just the count of the max register used. Higher count => higher * register pressure */ int work_registers; /* Used for cont/last hinting. Increase when a tex op is added. * Decrease when a tex op is removed. */ int texture_op_count; /* Mapping of texture register -> SSA index for unaliasing */ int texture_index[2]; /* If any path hits a discard instruction */ bool can_discard; /* The number of uniforms allowable for the fast path */ int uniform_cutoff; /* Count of instructions emitted from NIR overall, across all blocks */ int instruction_count; /* Alpha ref value passed in */ float alpha_ref; /* The index corresponding to the fragment output */ unsigned fragment_output; /* The mapping of sysvals to uniforms, the count, and the off-by-one inverse */ unsigned sysvals[MAX_SYSVAL_COUNT]; unsigned sysval_count; struct hash_table_u64 *sysval_to_id; } compiler_context; /* Helpers for manipulating the above structures (forming the driver IR) */ /* Append instruction to end of current block */ static inline midgard_instruction * mir_upload_ins(struct midgard_instruction ins) { midgard_instruction *heap = malloc(sizeof(ins)); memcpy(heap, &ins, sizeof(ins)); return heap; } static inline void emit_mir_instruction(struct compiler_context *ctx, struct midgard_instruction ins) { list_addtail(&(mir_upload_ins(ins))->link, &ctx->current_block->instructions); } static inline void mir_insert_instruction_before(struct midgard_instruction *tag, struct midgard_instruction ins) { list_addtail(&(mir_upload_ins(ins))->link, &tag->link); } static inline void mir_remove_instruction(struct midgard_instruction *ins) { list_del(&ins->link); } static inline midgard_instruction* mir_prev_op(struct midgard_instruction *ins) { return list_last_entry(&(ins->link), midgard_instruction, link); } static inline midgard_instruction* mir_next_op(struct midgard_instruction *ins) { return list_first_entry(&(ins->link), midgard_instruction, link); } #define mir_foreach_block(ctx, v) \ list_for_each_entry(struct midgard_block, v, &ctx->blocks, link) #define mir_foreach_block_from(ctx, from, v) \ list_for_each_entry_from(struct midgard_block, v, from, &ctx->blocks, link) #define mir_foreach_instr(ctx, v) \ list_for_each_entry(struct midgard_instruction, v, &ctx->current_block->instructions, link) #define mir_foreach_instr_safe(ctx, v) \ list_for_each_entry_safe(struct midgard_instruction, v, &ctx->current_block->instructions, link) #define mir_foreach_instr_in_block(block, v) \ list_for_each_entry(struct midgard_instruction, v, &block->instructions, link) #define mir_foreach_instr_in_block_safe(block, v) \ list_for_each_entry_safe(struct midgard_instruction, v, &block->instructions, link) #define mir_foreach_instr_in_block_safe_rev(block, v) \ list_for_each_entry_safe_rev(struct midgard_instruction, v, &block->instructions, link) #define mir_foreach_instr_in_block_from(block, v, from) \ list_for_each_entry_from(struct midgard_instruction, v, from, &block->instructions, link) #define mir_foreach_instr_in_block_from_rev(block, v, from) \ list_for_each_entry_from_rev(struct midgard_instruction, v, from, &block->instructions, link) #define mir_foreach_bundle_in_block(block, v) \ util_dynarray_foreach(&block->bundles, midgard_bundle, v) #define mir_foreach_instr_global(ctx, v) \ mir_foreach_block(ctx, v_block) \ mir_foreach_instr_in_block(v_block, v) static inline midgard_instruction * mir_last_in_block(struct midgard_block *block) { return list_last_entry(&block->instructions, struct midgard_instruction, link); } static inline midgard_block * mir_get_block(compiler_context *ctx, int idx) { struct list_head *lst = &ctx->blocks; while ((idx--) + 1) lst = lst->next; return (struct midgard_block *) lst; } static inline bool mir_is_alu_bundle(midgard_bundle *bundle) { return IS_ALU(bundle->tag); } /* MIR manipulation */ void mir_rewrite_index(compiler_context *ctx, unsigned old, unsigned new); void mir_rewrite_index_src(compiler_context *ctx, unsigned old, unsigned new); void mir_rewrite_index_dst(compiler_context *ctx, unsigned old, unsigned new); /* MIR printing */ void mir_print_instruction(midgard_instruction *ins); void mir_print_bundle(midgard_bundle *ctx); void mir_print_block(midgard_block *block); void mir_print_shader(compiler_context *ctx); /* MIR goodies */ static const midgard_vector_alu_src blank_alu_src = { .swizzle = SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_Z, COMPONENT_W), }; static const midgard_vector_alu_src blank_alu_src_xxxx = { .swizzle = SWIZZLE(COMPONENT_X, COMPONENT_X, COMPONENT_X, COMPONENT_X), }; static const midgard_scalar_alu_src blank_scalar_alu_src = { .full = true }; /* Used for encoding the unused source of 1-op instructions */ static const midgard_vector_alu_src zero_alu_src = { 0 }; /* 'Intrinsic' move for aliasing */ static inline midgard_instruction v_fmov(unsigned src, midgard_vector_alu_src mod, unsigned dest) { midgard_instruction ins = { .type = TAG_ALU_4, .ssa_args = { .src0 = SSA_UNUSED_1, .src1 = src, .dest = dest, }, .alu = { .op = midgard_alu_op_fmov, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_none, .mask = 0xFF, .src1 = vector_alu_srco_unsigned(zero_alu_src), .src2 = vector_alu_srco_unsigned(mod) }, }; return ins; } /* Scheduling */ void schedule_program(compiler_context *ctx); /* Register allocation */ struct ra_graph; struct ra_graph* allocate_registers(compiler_context *ctx); void install_registers(compiler_context *ctx, struct ra_graph *g); bool mir_is_live_after(compiler_context *ctx, midgard_block *block, midgard_instruction *start, int src); bool mir_has_multiple_writes(compiler_context *ctx, int src); void mir_create_pipeline_registers(compiler_context *ctx); /* Final emission */ void emit_binary_bundle( compiler_context *ctx, midgard_bundle *bundle, struct util_dynarray *emission, int next_tag); #endif