/* * Copyright (C) 2020 Collabora Ltd. * * 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. * * Authors (Collabora): * Alyssa Rosenzweig */ #ifndef __BIFROST_COMPILER_H #define __BIFROST_COMPILER_H #include "bifrost.h" #include "compiler/nir/nir.h" #include "panfrost/util/pan_ir.h" /* Bifrost opcodes are tricky -- the same op may exist on both FMA and * ADD with two completely different opcodes, and opcodes can be varying * length in some cases. Then we have different opcodes for int vs float * and then sometimes even for different typesizes. Further, virtually * every op has a number of flags which depend on the op. In constrast * to Midgard where you have a strict ALU/LDST/TEX division and within * ALU you have strict int/float and that's it... here it's a *lot* more * involved. As such, we use something much higher level for our IR, * encoding "classes" of operations, letting the opcode details get * sorted out at emit time. * * Please keep this list alphabetized. Please use a dictionary if you * don't know how to do that. */ enum bi_class { BI_ADD, BI_ATEST, BI_BRANCH, BI_CMP, BI_BLEND, BI_BITWISE, BI_COMBINE, BI_CONVERT, BI_CSEL, BI_DISCARD, BI_FMA, BI_FMOV, BI_FREXP, BI_ISUB, BI_LOAD, BI_LOAD_UNIFORM, BI_LOAD_ATTR, BI_LOAD_VAR, BI_LOAD_VAR_ADDRESS, BI_MINMAX, BI_MOV, BI_REDUCE_FMA, BI_SHIFT, BI_STORE, BI_STORE_VAR, BI_SPECIAL, /* _FAST on supported GPUs */ BI_SWIZZLE, BI_TABLE, BI_TEX, BI_ROUND, BI_NUM_CLASSES }; /* Properties of a class... */ extern unsigned bi_class_props[BI_NUM_CLASSES]; /* abs/neg/outmod valid for a float op */ #define BI_MODS (1 << 0) /* Generic enough that little class-specific information is required. In other * words, it acts as a "normal" ALU op, even if the encoding ends up being * irregular enough to warrant a separate class */ #define BI_GENERIC (1 << 1) /* Accepts a bifrost_roundmode */ #define BI_ROUNDMODE (1 << 2) /* Can be scheduled to FMA */ #define BI_SCHED_FMA (1 << 3) /* Can be scheduled to ADD */ #define BI_SCHED_ADD (1 << 4) /* Most ALU ops can do either, actually */ #define BI_SCHED_ALL (BI_SCHED_FMA | BI_SCHED_ADD) /* Along with setting BI_SCHED_ADD, eats up the entire cycle, so FMA must be * nopped out. Used for _FAST operations. */ #define BI_SCHED_SLOW (1 << 5) /* Swizzling allowed for the 8/16-bit source */ #define BI_SWIZZLABLE (1 << 6) /* For scheduling purposes this is a high latency instruction and must be at * the end of a clause. Implies ADD */ #define BI_SCHED_HI_LATENCY (1 << 7) /* Intrinsic is vectorized and should read 4 components in the first source * regardless of writemask */ #define BI_VECTOR (1 << 8) /* Use a data register for src0/dest respectively, bypassing the usual * register accessor. Mutually exclusive. */ #define BI_DATA_REG_SRC (1 << 9) #define BI_DATA_REG_DEST (1 << 10) /* Quirk: cannot encode multiple abs on FMA in fp16 mode */ #define BI_NO_ABS_ABS_FP16_FMA (1 << 11) /* It can't get any worse than csel4... can it? */ #define BIR_SRC_COUNT 4 /* BI_LD_VARY */ struct bi_load_vary { enum bifrost_interp_mode interp_mode; bool reuse; bool flat; }; /* BI_BRANCH encoding the details of the branch itself as well as a pointer to * the target. We forward declare bi_block since this is mildly circular (not * strictly, but this order of the file makes more sense I think) * * We define our own enum of conditions since the conditions in the hardware * packed in crazy ways that would make manipulation unweildly (meaning changes * based on port swapping, etc), so we defer dealing with that until emit time. * Likewise, we expose NIR types instead of the crazy branch types, although * the restrictions do eventually apply of course. */ struct bi_block; enum bi_cond { BI_COND_ALWAYS, BI_COND_LT, BI_COND_LE, BI_COND_GE, BI_COND_GT, BI_COND_EQ, BI_COND_NE, }; struct bi_branch { /* Types are specified in src_types and must be compatible (either both * int, or both float, 16/32, and same size or 32/16 if float. Types * ignored if BI_COND_ALWAYS is set for an unconditional branch. */ enum bi_cond cond; struct bi_block *target; }; /* Opcodes within a class */ enum bi_minmax_op { BI_MINMAX_MIN, BI_MINMAX_MAX }; enum bi_bitwise_op { BI_BITWISE_AND, BI_BITWISE_OR, BI_BITWISE_XOR }; enum bi_round_op { BI_ROUND_MODE, /* use round mode */ BI_ROUND_ROUND /* i.e.: fround() */ }; enum bi_table_op { /* fp32 log2() with low precision, suitable for GL or half_log2() in * CL. In the first argument, takes x. Letting u be such that x = * 2^{-m} u with m integer and 0.75 <= u < 1.5, returns * log2(u) / (u - 1). */ BI_TABLE_LOG2_U_OVER_U_1_LOW, }; enum bi_reduce_op { /* Takes two fp32 arguments and returns x + frexp(y). Used in * low-precision log2 argument reduction on newer models. */ BI_REDUCE_ADD_FREXPM, }; enum bi_frexp_op { BI_FREXPE_LOG, }; enum bi_special_op { BI_SPECIAL_FRCP, BI_SPECIAL_FRSQ, /* fp32 exp2() with low precision, suitable for half_exp2() in CL or * exp2() in GL. In the first argument, it takes f2i_rte(x * 2^24). In * the second, it takes x itself. */ BI_SPECIAL_EXP2_LOW, }; typedef struct { struct list_head link; /* Must be first */ enum bi_class type; /* Indices, see bir_ssa_index etc. Note zero is special cased * to "no argument" */ unsigned dest; unsigned src[BIR_SRC_COUNT]; /* If one of the sources has BIR_INDEX_CONSTANT */ union { uint64_t u64; uint32_t u32; uint16_t u16[2]; uint8_t u8[4]; } constant; /* Floating-point modifiers, type/class permitting. If not * allowed for the type/class, these are ignored. */ enum bifrost_outmod outmod; bool src_abs[BIR_SRC_COUNT]; bool src_neg[BIR_SRC_COUNT]; /* Round mode (requires BI_ROUNDMODE) */ enum bifrost_roundmode roundmode; /* Writemask (bit for each affected byte). This is quite restricted -- * ALU ops can only write to a single channel (exception: <32 in which * you can write to 32/N contiguous aligned channels). Load/store can * only write to all channels at once, in a sense. But it's still * better to use this generic form than have synthetic ops flying * about, since we're not essentially vector for RA purposes. */ uint16_t writemask; /* Destination type. Usually the type of the instruction * itself, but if sources and destination have different * types, the type of the destination wins (so f2i would be * int). Zero if there is no destination. Bitsize included */ nir_alu_type dest_type; /* Source types if required by the class */ nir_alu_type src_types[BIR_SRC_COUNT]; /* If the source type is 8-bit or 16-bit such that SIMD is possible, * and the class has BI_SWIZZLABLE, this is a swizzle in the usual * sense. On non-SIMD instructions, it can be used for component * selection, so we don't have to special case extraction. */ uint8_t swizzle[BIR_SRC_COUNT][NIR_MAX_VEC_COMPONENTS]; /* A class-specific op from which the actual opcode can be derived * (along with the above information) */ union { enum bi_minmax_op minmax; enum bi_bitwise_op bitwise; enum bi_round_op round; enum bi_special_op special; enum bi_reduce_op reduce; enum bi_table_op table; enum bi_frexp_op frexp; enum bi_cond compare; /* For FMA/ADD, should we add a biased exponent? */ bool mscale; } op; /* Union for class-specific information */ union { enum bifrost_minmax_mode minmax; struct bi_load_vary load_vary; struct bi_branch branch; /* For CSEL, the comparison op. BI_COND_ALWAYS doesn't make * sense here but you can always just use a move for that */ enum bi_cond csel_cond; /* For BLEND -- the location 0-7 */ unsigned blend_location; /* For STORE, STORE_VAR -- channel count */ unsigned store_channels; }; } bi_instruction; /* Scheduling takes place in two steps. Step 1 groups instructions within a * block into distinct clauses (bi_clause). Step 2 schedules instructions * within a clause into FMA/ADD pairs (bi_bundle). * * A bi_bundle contains two paired instruction pointers. If a slot is unfilled, * leave it NULL; the emitter will fill in a nop. */ typedef struct { bi_instruction *fma; bi_instruction *add; } bi_bundle; typedef struct { struct list_head link; /* A clause can have 8 instructions in bundled FMA/ADD sense, so there * can be 8 bundles. But each bundle can have both an FMA and an ADD, * so a clause can have up to 16 bi_instructions. Whether bundles or * instructions are used depends on where in scheduling we are. */ unsigned instruction_count; unsigned bundle_count; union { bi_instruction *instructions[16]; bi_bundle bundles[8]; }; /* For scoreboarding -- the clause ID (this is not globally unique!) * and its dependencies in terms of other clauses, computed during * scheduling and used when emitting code. Dependencies expressed as a * bitfield matching the hardware, except shifted by a clause (the * shift back to the ISA's off-by-one encoding is worked out when * emitting clauses) */ unsigned scoreboard_id; uint8_t dependencies; /* Back-to-back corresponds directly to the back-to-back bit. Branch * conditional corresponds to the branch conditional bit except that in * the emitted code it's always set if back-to-bit is, whereas we use * the actual value (without back-to-back so to speak) internally */ bool back_to_back; bool branch_conditional; /* Assigned data register */ unsigned data_register; /* Corresponds to the usual bit but shifted by a clause */ bool data_register_write_barrier; /* Constants read by this clause. ISA limit. */ uint64_t constants[8]; unsigned constant_count; /* What type of high latency instruction is here, basically */ unsigned clause_type; } bi_clause; typedef struct bi_block { pan_block base; /* must be first */ /* If true, uses clauses; if false, uses instructions */ bool scheduled; struct list_head clauses; /* list of bi_clause */ } bi_block; typedef struct { nir_shader *nir; gl_shader_stage stage; struct list_head blocks; /* list of bi_block */ struct panfrost_sysvals sysvals; uint32_t quirks; /* During NIR->BIR */ nir_function_impl *impl; bi_block *current_block; unsigned block_name_count; bi_block *after_block; bi_block *break_block; bi_block *continue_block; bool emitted_atest; /* For creating temporaries */ unsigned temp_alloc; /* Analysis results */ bool has_liveness; /* Stats for shader-db */ unsigned instruction_count; unsigned loop_count; } bi_context; static inline bi_instruction * bi_emit(bi_context *ctx, bi_instruction ins) { bi_instruction *u = rzalloc(ctx, bi_instruction); memcpy(u, &ins, sizeof(ins)); list_addtail(&u->link, &ctx->current_block->base.instructions); return u; } static inline bi_instruction * bi_emit_before(bi_context *ctx, bi_instruction *tag, bi_instruction ins) { bi_instruction *u = rzalloc(ctx, bi_instruction); memcpy(u, &ins, sizeof(ins)); list_addtail(&u->link, &tag->link); return u; } static inline void bi_remove_instruction(bi_instruction *ins) { list_del(&ins->link); } /* So we can distinguish between SSA/reg/sentinel quickly */ #define BIR_NO_ARG (0) #define BIR_IS_REG (1) /* If high bits are set, instead of SSA/registers, we have specials indexed by * the low bits if necessary. * * Fixed register: do not allocate register, do not collect $200. * Uniform: access a uniform register given by low bits. * Constant: access the specified constant (specifies a bit offset / shift) * Zero: special cased to avoid wasting a constant * Passthrough: a bifrost_packed_src to passthrough T/T0/T1 */ #define BIR_INDEX_REGISTER (1 << 31) #define BIR_INDEX_UNIFORM (1 << 30) #define BIR_INDEX_CONSTANT (1 << 29) #define BIR_INDEX_ZERO (1 << 28) #define BIR_INDEX_PASS (1 << 27) /* Keep me synced please so we can check src & BIR_SPECIAL */ #define BIR_SPECIAL ((BIR_INDEX_REGISTER | BIR_INDEX_UNIFORM) | \ (BIR_INDEX_CONSTANT | BIR_INDEX_ZERO | BIR_INDEX_PASS)) static inline unsigned bi_max_temp(bi_context *ctx) { unsigned alloc = MAX2(ctx->impl->reg_alloc, ctx->impl->ssa_alloc); return ((alloc + 2 + ctx->temp_alloc) << 1); } static inline unsigned bi_make_temp(bi_context *ctx) { return (ctx->impl->ssa_alloc + 1 + ctx->temp_alloc++) << 1; } static inline unsigned bi_make_temp_reg(bi_context *ctx) { return ((ctx->impl->reg_alloc + ctx->temp_alloc++) << 1) | BIR_IS_REG; } static inline unsigned bir_ssa_index(nir_ssa_def *ssa) { /* Off-by-one ensures BIR_NO_ARG is skipped */ return ((ssa->index + 1) << 1) | 0; } static inline unsigned bir_src_index(nir_src *src) { if (src->is_ssa) return bir_ssa_index(src->ssa); else { assert(!src->reg.indirect); return (src->reg.reg->index << 1) | BIR_IS_REG; } } static inline unsigned bir_dest_index(nir_dest *dst) { if (dst->is_ssa) return bir_ssa_index(&dst->ssa); else { assert(!dst->reg.indirect); return (dst->reg.reg->index << 1) | BIR_IS_REG; } } /* Iterators for Bifrost IR */ #define bi_foreach_block(ctx, v) \ list_for_each_entry(pan_block, v, &ctx->blocks, link) #define bi_foreach_block_from(ctx, from, v) \ list_for_each_entry_from(pan_block, v, from, &ctx->blocks, link) #define bi_foreach_instr_in_block(block, v) \ list_for_each_entry(bi_instruction, v, &(block)->base.instructions, link) #define bi_foreach_instr_in_block_rev(block, v) \ list_for_each_entry_rev(bi_instruction, v, &(block)->base.instructions, link) #define bi_foreach_instr_in_block_safe(block, v) \ list_for_each_entry_safe(bi_instruction, v, &(block)->base.instructions, link) #define bi_foreach_instr_in_block_safe_rev(block, v) \ list_for_each_entry_safe_rev(bi_instruction, v, &(block)->base.instructions, link) #define bi_foreach_instr_in_block_from(block, v, from) \ list_for_each_entry_from(bi_instruction, v, from, &(block)->base.instructions, link) #define bi_foreach_instr_in_block_from_rev(block, v, from) \ list_for_each_entry_from_rev(bi_instruction, v, from, &(block)->base.instructions, link) #define bi_foreach_clause_in_block(block, v) \ list_for_each_entry(bi_clause, v, &(block)->clauses, link) #define bi_foreach_instr_global(ctx, v) \ bi_foreach_block(ctx, v_block) \ bi_foreach_instr_in_block((bi_block *) v_block, v) #define bi_foreach_instr_global_safe(ctx, v) \ bi_foreach_block(ctx, v_block) \ bi_foreach_instr_in_block_safe((bi_block *) v_block, v) /* Based on set_foreach, expanded with automatic type casts */ #define bi_foreach_predecessor(blk, v) \ struct set_entry *_entry_##v; \ bi_block *v; \ for (_entry_##v = _mesa_set_next_entry(blk->base.predecessors, NULL), \ v = (bi_block *) (_entry_##v ? _entry_##v->key : NULL); \ _entry_##v != NULL; \ _entry_##v = _mesa_set_next_entry(blk->base.predecessors, _entry_##v), \ v = (bi_block *) (_entry_##v ? _entry_##v->key : NULL)) #define bi_foreach_src(ins, v) \ for (unsigned v = 0; v < ARRAY_SIZE(ins->src); ++v) static inline bi_instruction * bi_prev_op(bi_instruction *ins) { return list_last_entry(&(ins->link), bi_instruction, link); } static inline bi_instruction * bi_next_op(bi_instruction *ins) { return list_first_entry(&(ins->link), bi_instruction, link); } static inline pan_block * pan_next_block(pan_block *block) { return list_first_entry(&(block->link), pan_block, link); } /* Special functions */ void bi_emit_fexp2(bi_context *ctx, nir_alu_instr *instr); /* BIR manipulation */ bool bi_has_outmod(bi_instruction *ins); bool bi_has_source_mods(bi_instruction *ins); bool bi_is_src_swizzled(bi_instruction *ins, unsigned s); bool bi_has_arg(bi_instruction *ins, unsigned arg); uint16_t bi_from_bytemask(uint16_t bytemask, unsigned bytes); unsigned bi_get_component_count(bi_instruction *ins, unsigned s); unsigned bi_load32_components(bi_instruction *ins); uint16_t bi_bytemask_of_read_components(bi_instruction *ins, unsigned node); uint64_t bi_get_immediate(bi_instruction *ins, unsigned index); bool bi_writes_component(bi_instruction *ins, unsigned comp); /* BIR passes */ void bi_lower_combine(bi_context *ctx, bi_block *block); bool bi_opt_dead_code_eliminate(bi_context *ctx, bi_block *block); void bi_schedule(bi_context *ctx); void bi_register_allocate(bi_context *ctx); /* Liveness */ void bi_compute_liveness(bi_context *ctx); void bi_liveness_ins_update(uint16_t *live, bi_instruction *ins, unsigned max); void bi_invalidate_liveness(bi_context *ctx); bool bi_is_live_after(bi_context *ctx, bi_block *block, bi_instruction *start, int src); /* Code emit */ void bi_pack(bi_context *ctx, struct util_dynarray *emission); #endif