/* * Copyright (C) 2018-2019 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. */ #include #include #include #include #include #include #include #include #include "main/mtypes.h" #include "compiler/glsl/glsl_to_nir.h" #include "compiler/nir_types.h" #include "main/imports.h" #include "compiler/nir/nir_builder.h" #include "util/half_float.h" #include "util/u_debug.h" #include "util/u_dynarray.h" #include "util/list.h" #include "main/mtypes.h" #include "midgard.h" #include "midgard_nir.h" #include "midgard_compile.h" #include "midgard_ops.h" #include "helpers.h" #include "compiler.h" #include "disassemble.h" static const struct debug_named_value debug_options[] = { {"msgs", MIDGARD_DBG_MSGS, "Print debug messages"}, {"shaders", MIDGARD_DBG_SHADERS, "Dump shaders in NIR and MIR"}, DEBUG_NAMED_VALUE_END }; DEBUG_GET_ONCE_FLAGS_OPTION(midgard_debug, "MIDGARD_MESA_DEBUG", debug_options, 0) int midgard_debug = 0; #define DBG(fmt, ...) \ do { if (midgard_debug & MIDGARD_DBG_MSGS) \ fprintf(stderr, "%s:%d: "fmt, \ __FUNCTION__, __LINE__, ##__VA_ARGS__); } while (0) static bool midgard_is_branch_unit(unsigned unit) { return (unit == ALU_ENAB_BRANCH) || (unit == ALU_ENAB_BR_COMPACT); } static void midgard_block_add_successor(midgard_block *block, midgard_block *successor) { block->successors[block->nr_successors++] = successor; assert(block->nr_successors <= ARRAY_SIZE(block->successors)); } /* Helpers to generate midgard_instruction's using macro magic, since every * driver seems to do it that way */ #define EMIT(op, ...) emit_mir_instruction(ctx, v_##op(__VA_ARGS__)); #define SWIZZLE_XYZW SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_Z, COMPONENT_W) #define SWIZZLE_XYXX SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_X, COMPONENT_X) #define SWIZZLE_XXXX SWIZZLE(COMPONENT_X, COMPONENT_X, COMPONENT_X, COMPONENT_X) #define SWIZZLE_WWWW SWIZZLE(COMPONENT_W, COMPONENT_W, COMPONENT_W, COMPONENT_W) #define M_LOAD_STORE(name, rname, uname) \ static midgard_instruction m_##name(unsigned ssa, unsigned address) { \ midgard_instruction i = { \ .type = TAG_LOAD_STORE_4, \ .ssa_args = { \ .rname = ssa, \ .uname = -1, \ .src1 = -1 \ }, \ .load_store = { \ .op = midgard_op_##name, \ .mask = 0xF, \ .swizzle = SWIZZLE_XYZW, \ .address = address \ } \ }; \ \ return i; \ } #define M_LOAD(name) M_LOAD_STORE(name, dest, src0) #define M_STORE(name) M_LOAD_STORE(name, src0, dest) /* Inputs a NIR ALU source, with modifiers attached if necessary, and outputs * the corresponding Midgard source */ static midgard_vector_alu_src vector_alu_modifiers(nir_alu_src *src, bool is_int) { if (!src) return blank_alu_src; midgard_vector_alu_src alu_src = { .rep_low = 0, .rep_high = 0, .half = 0, /* TODO */ .swizzle = SWIZZLE_FROM_ARRAY(src->swizzle) }; if (is_int) { /* TODO: sign-extend/zero-extend */ alu_src.mod = midgard_int_normal; /* These should have been lowered away */ assert(!(src->abs || src->negate)); } else { alu_src.mod = (src->abs << 0) | (src->negate << 1); } return alu_src; } /* load/store instructions have both 32-bit and 16-bit variants, depending on * whether we are using vectors composed of highp or mediump. At the moment, we * don't support half-floats -- this requires changes in other parts of the * compiler -- therefore the 16-bit versions are commented out. */ //M_LOAD(ld_attr_16); M_LOAD(ld_attr_32); //M_LOAD(ld_vary_16); M_LOAD(ld_vary_32); //M_LOAD(ld_uniform_16); M_LOAD(ld_uniform_32); M_LOAD(ld_color_buffer_8); //M_STORE(st_vary_16); M_STORE(st_vary_32); M_STORE(st_cubemap_coords); static midgard_instruction v_alu_br_compact_cond(midgard_jmp_writeout_op op, unsigned tag, signed offset, unsigned cond) { midgard_branch_cond branch = { .op = op, .dest_tag = tag, .offset = offset, .cond = cond }; uint16_t compact; memcpy(&compact, &branch, sizeof(branch)); midgard_instruction ins = { .type = TAG_ALU_4, .unit = ALU_ENAB_BR_COMPACT, .prepacked_branch = true, .compact_branch = true, .br_compact = compact }; if (op == midgard_jmp_writeout_op_writeout) ins.writeout = true; return ins; } static midgard_instruction v_branch(bool conditional, bool invert) { midgard_instruction ins = { .type = TAG_ALU_4, .unit = ALU_ENAB_BRANCH, .compact_branch = true, .branch = { .conditional = conditional, .invert_conditional = invert } }; return ins; } static midgard_branch_extended midgard_create_branch_extended( midgard_condition cond, midgard_jmp_writeout_op op, unsigned dest_tag, signed quadword_offset) { /* For unclear reasons, the condition code is repeated 8 times */ uint16_t duplicated_cond = (cond << 14) | (cond << 12) | (cond << 10) | (cond << 8) | (cond << 6) | (cond << 4) | (cond << 2) | (cond << 0); midgard_branch_extended branch = { .op = op, .dest_tag = dest_tag, .offset = quadword_offset, .cond = duplicated_cond }; return branch; } static void attach_constants(compiler_context *ctx, midgard_instruction *ins, void *constants, int name) { ins->has_constants = true; memcpy(&ins->constants, constants, 16); } static int glsl_type_size(const struct glsl_type *type, bool bindless) { return glsl_count_attribute_slots(type, false); } /* Lower fdot2 to a vector multiplication followed by channel addition */ static void midgard_nir_lower_fdot2_body(nir_builder *b, nir_alu_instr *alu) { if (alu->op != nir_op_fdot2) return; b->cursor = nir_before_instr(&alu->instr); nir_ssa_def *src0 = nir_ssa_for_alu_src(b, alu, 0); nir_ssa_def *src1 = nir_ssa_for_alu_src(b, alu, 1); nir_ssa_def *product = nir_fmul(b, src0, src1); nir_ssa_def *sum = nir_fadd(b, nir_channel(b, product, 0), nir_channel(b, product, 1)); /* Replace the fdot2 with this sum */ nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa, nir_src_for_ssa(sum)); } static int midgard_nir_sysval_for_intrinsic(nir_intrinsic_instr *instr) { switch (instr->intrinsic) { case nir_intrinsic_load_viewport_scale: return PAN_SYSVAL_VIEWPORT_SCALE; case nir_intrinsic_load_viewport_offset: return PAN_SYSVAL_VIEWPORT_OFFSET; default: return -1; } } static void midgard_nir_assign_sysval_body(compiler_context *ctx, nir_instr *instr) { int sysval = -1; if (instr->type == nir_instr_type_intrinsic) { nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); sysval = midgard_nir_sysval_for_intrinsic(intr); } if (sysval < 0) return; /* We have a sysval load; check if it's already been assigned */ if (_mesa_hash_table_u64_search(ctx->sysval_to_id, sysval)) return; /* It hasn't -- so assign it now! */ unsigned id = ctx->sysval_count++; _mesa_hash_table_u64_insert(ctx->sysval_to_id, sysval, (void *) ((uintptr_t) id + 1)); ctx->sysvals[id] = sysval; } static void midgard_nir_assign_sysvals(compiler_context *ctx, nir_shader *shader) { ctx->sysval_count = 0; nir_foreach_function(function, shader) { if (!function->impl) continue; nir_foreach_block(block, function->impl) { nir_foreach_instr_safe(instr, block) { midgard_nir_assign_sysval_body(ctx, instr); } } } } static bool midgard_nir_lower_fdot2(nir_shader *shader) { bool progress = false; nir_foreach_function(function, shader) { if (!function->impl) continue; nir_builder _b; nir_builder *b = &_b; nir_builder_init(b, function->impl); nir_foreach_block(block, function->impl) { nir_foreach_instr_safe(instr, block) { if (instr->type != nir_instr_type_alu) continue; nir_alu_instr *alu = nir_instr_as_alu(instr); midgard_nir_lower_fdot2_body(b, alu); progress |= true; } } nir_metadata_preserve(function->impl, nir_metadata_block_index | nir_metadata_dominance); } return progress; } static void optimise_nir(nir_shader *nir) { bool progress; unsigned lower_flrp = (nir->options->lower_flrp16 ? 16 : 0) | (nir->options->lower_flrp32 ? 32 : 0) | (nir->options->lower_flrp64 ? 64 : 0); NIR_PASS(progress, nir, nir_lower_regs_to_ssa); NIR_PASS(progress, nir, midgard_nir_lower_fdot2); NIR_PASS(progress, nir, nir_lower_idiv); nir_lower_tex_options lower_tex_options = { .lower_rect = true, .lower_txp = ~0 }; NIR_PASS(progress, nir, nir_lower_tex, &lower_tex_options); do { progress = false; NIR_PASS(progress, nir, nir_lower_var_copies); NIR_PASS(progress, nir, nir_lower_vars_to_ssa); NIR_PASS(progress, nir, nir_copy_prop); NIR_PASS(progress, nir, nir_opt_dce); NIR_PASS(progress, nir, nir_opt_dead_cf); NIR_PASS(progress, nir, nir_opt_cse); NIR_PASS(progress, nir, nir_opt_peephole_select, 64, false, true); NIR_PASS(progress, nir, nir_opt_algebraic); NIR_PASS(progress, nir, nir_opt_constant_folding); if (lower_flrp != 0) { bool lower_flrp_progress = false; NIR_PASS(lower_flrp_progress, nir, nir_lower_flrp, lower_flrp, false /* always_precise */, nir->options->lower_ffma); if (lower_flrp_progress) { NIR_PASS(progress, nir, nir_opt_constant_folding); progress = true; } /* Nothing should rematerialize any flrps, so we only * need to do this lowering once. */ lower_flrp = 0; } NIR_PASS(progress, nir, nir_opt_undef); NIR_PASS(progress, nir, nir_opt_loop_unroll, nir_var_shader_in | nir_var_shader_out | nir_var_function_temp); /* TODO: Enable vectorize when merged upstream */ // NIR_PASS(progress, nir, nir_opt_vectorize); } while (progress); /* Must be run at the end to prevent creation of fsin/fcos ops */ NIR_PASS(progress, nir, midgard_nir_scale_trig); do { progress = false; NIR_PASS(progress, nir, nir_opt_dce); NIR_PASS(progress, nir, nir_opt_algebraic); NIR_PASS(progress, nir, nir_opt_constant_folding); NIR_PASS(progress, nir, nir_copy_prop); } while (progress); NIR_PASS(progress, nir, nir_opt_algebraic_late); /* We implement booleans as 32-bit 0/~0 */ NIR_PASS(progress, nir, nir_lower_bool_to_int32); /* Now that booleans are lowered, we can run out late opts */ NIR_PASS(progress, nir, midgard_nir_lower_algebraic_late); /* Lower mods for float ops only. Integer ops don't support modifiers * (saturate doesn't make sense on integers, neg/abs require dedicated * instructions) */ NIR_PASS(progress, nir, nir_lower_to_source_mods, nir_lower_float_source_mods); NIR_PASS(progress, nir, nir_copy_prop); NIR_PASS(progress, nir, nir_opt_dce); /* Take us out of SSA */ NIR_PASS(progress, nir, nir_lower_locals_to_regs); NIR_PASS(progress, nir, nir_convert_from_ssa, true); /* We are a vector architecture; write combine where possible */ NIR_PASS(progress, nir, nir_move_vec_src_uses_to_dest); NIR_PASS(progress, nir, nir_lower_vec_to_movs); NIR_PASS(progress, nir, nir_opt_dce); } /* Front-half of aliasing the SSA slots, merely by inserting the flag in the * appropriate hash table. Intentional off-by-one to avoid confusing NULL with * r0. See the comments in compiler_context */ static void alias_ssa(compiler_context *ctx, int dest, int src) { _mesa_hash_table_u64_insert(ctx->ssa_to_alias, dest + 1, (void *) ((uintptr_t) src + 1)); _mesa_set_add(ctx->leftover_ssa_to_alias, (void *) (uintptr_t) (dest + 1)); } /* ...or undo it, after which the original index will be used (dummy move should be emitted alongside this) */ static void unalias_ssa(compiler_context *ctx, int dest) { _mesa_hash_table_u64_remove(ctx->ssa_to_alias, dest + 1); /* TODO: Remove from leftover or no? */ } /* Do not actually emit a load; instead, cache the constant for inlining */ static void emit_load_const(compiler_context *ctx, nir_load_const_instr *instr) { nir_ssa_def def = instr->def; float *v = rzalloc_array(NULL, float, 4); nir_const_load_to_arr(v, instr, f32); _mesa_hash_table_u64_insert(ctx->ssa_constants, def.index + 1, v); } static unsigned nir_src_index(compiler_context *ctx, nir_src *src) { if (src->is_ssa) return src->ssa->index; else { assert(!src->reg.indirect); return ctx->func->impl->ssa_alloc + src->reg.reg->index; } } static unsigned nir_dest_index(compiler_context *ctx, nir_dest *dst) { if (dst->is_ssa) return dst->ssa.index; else { assert(!dst->reg.indirect); return ctx->func->impl->ssa_alloc + dst->reg.reg->index; } } static unsigned nir_alu_src_index(compiler_context *ctx, nir_alu_src *src) { return nir_src_index(ctx, &src->src); } static bool nir_is_non_scalar_swizzle(nir_alu_src *src, unsigned nr_components) { unsigned comp = src->swizzle[0]; for (unsigned c = 1; c < nr_components; ++c) { if (src->swizzle[c] != comp) return true; } return false; } /* Midgard puts scalar conditionals in r31.w; move an arbitrary source (the * output of a conditional test) into that register */ static void emit_condition(compiler_context *ctx, nir_src *src, bool for_branch, unsigned component) { int condition = nir_src_index(ctx, src); /* Source to swizzle the desired component into w */ const midgard_vector_alu_src alu_src = { .swizzle = SWIZZLE(component, component, component, component), }; /* There is no boolean move instruction. Instead, we simulate a move by * ANDing the condition with itself to get it into r31.w */ midgard_instruction ins = { .type = TAG_ALU_4, /* We need to set the conditional as close as possible */ .precede_break = true, .unit = for_branch ? UNIT_SMUL : UNIT_SADD, .ssa_args = { .src0 = condition, .src1 = condition, .dest = SSA_FIXED_REGISTER(31), }, .alu = { .op = midgard_alu_op_iand, .outmod = midgard_outmod_int_wrap, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_none, .mask = (0x3 << 6), /* w */ .src1 = vector_alu_srco_unsigned(alu_src), .src2 = vector_alu_srco_unsigned(alu_src) }, }; emit_mir_instruction(ctx, ins); } /* Or, for mixed conditions (with csel_v), here's a vector version using all of * r31 instead */ static void emit_condition_mixed(compiler_context *ctx, nir_alu_src *src, unsigned nr_comp) { int condition = nir_src_index(ctx, &src->src); /* Source to swizzle the desired component into w */ const midgard_vector_alu_src alu_src = { .swizzle = SWIZZLE_FROM_ARRAY(src->swizzle), }; /* There is no boolean move instruction. Instead, we simulate a move by * ANDing the condition with itself to get it into r31.w */ midgard_instruction ins = { .type = TAG_ALU_4, .precede_break = true, .ssa_args = { .src0 = condition, .src1 = condition, .dest = SSA_FIXED_REGISTER(31), }, .alu = { .op = midgard_alu_op_iand, .outmod = midgard_outmod_int_wrap, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_none, .mask = expand_writemask((1 << nr_comp) - 1), .src1 = vector_alu_srco_unsigned(alu_src), .src2 = vector_alu_srco_unsigned(alu_src) }, }; emit_mir_instruction(ctx, ins); } /* Likewise, indirect offsets are put in r27.w. TODO: Allow componentwise * pinning to eliminate this move in all known cases */ static void emit_indirect_offset(compiler_context *ctx, nir_src *src) { int offset = nir_src_index(ctx, src); midgard_instruction ins = { .type = TAG_ALU_4, .ssa_args = { .src0 = SSA_UNUSED_1, .src1 = offset, .dest = SSA_FIXED_REGISTER(REGISTER_OFFSET), }, .alu = { .op = midgard_alu_op_imov, .outmod = midgard_outmod_int_wrap, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_none, .mask = (0x3 << 6), /* w */ .src1 = vector_alu_srco_unsigned(zero_alu_src), .src2 = vector_alu_srco_unsigned(blank_alu_src_xxxx) }, }; emit_mir_instruction(ctx, ins); } #define ALU_CASE(nir, _op) \ case nir_op_##nir: \ op = midgard_alu_op_##_op; \ break; static bool nir_is_fzero_constant(nir_src src) { if (!nir_src_is_const(src)) return false; for (unsigned c = 0; c < nir_src_num_components(src); ++c) { if (nir_src_comp_as_float(src, c) != 0.0) return false; } return true; } static void emit_alu(compiler_context *ctx, nir_alu_instr *instr) { bool is_ssa = instr->dest.dest.is_ssa; unsigned dest = nir_dest_index(ctx, &instr->dest.dest); unsigned nr_components = is_ssa ? instr->dest.dest.ssa.num_components : instr->dest.dest.reg.reg->num_components; unsigned nr_inputs = nir_op_infos[instr->op].num_inputs; /* Most Midgard ALU ops have a 1:1 correspondance to NIR ops; these are * supported. A few do not and are commented for now. Also, there are a * number of NIR ops which Midgard does not support and need to be * lowered, also TODO. This switch block emits the opcode and calling * convention of the Midgard instruction; actual packing is done in * emit_alu below */ unsigned op; switch (instr->op) { ALU_CASE(fadd, fadd); ALU_CASE(fmul, fmul); ALU_CASE(fmin, fmin); ALU_CASE(fmax, fmax); ALU_CASE(imin, imin); ALU_CASE(imax, imax); ALU_CASE(umin, umin); ALU_CASE(umax, umax); ALU_CASE(ffloor, ffloor); ALU_CASE(fround_even, froundeven); ALU_CASE(ftrunc, ftrunc); ALU_CASE(fceil, fceil); ALU_CASE(fdot3, fdot3); ALU_CASE(fdot4, fdot4); ALU_CASE(iadd, iadd); ALU_CASE(isub, isub); ALU_CASE(imul, imul); /* Zero shoved as second-arg */ ALU_CASE(iabs, iabsdiff); ALU_CASE(mov, imov); ALU_CASE(feq32, feq); ALU_CASE(fne32, fne); ALU_CASE(flt32, flt); ALU_CASE(ieq32, ieq); ALU_CASE(ine32, ine); ALU_CASE(ilt32, ilt); ALU_CASE(ult32, ult); /* We don't have a native b2f32 instruction. Instead, like many * GPUs, we exploit booleans as 0/~0 for false/true, and * correspondingly AND * by 1.0 to do the type conversion. For the moment, prime us * to emit: * * iand [whatever], #0 * * At the end of emit_alu (as MIR), we'll fix-up the constant */ ALU_CASE(b2f32, iand); ALU_CASE(b2i32, iand); /* Likewise, we don't have a dedicated f2b32 instruction, but * we can do a "not equal to 0.0" test. */ ALU_CASE(f2b32, fne); ALU_CASE(i2b32, ine); ALU_CASE(frcp, frcp); ALU_CASE(frsq, frsqrt); ALU_CASE(fsqrt, fsqrt); ALU_CASE(fexp2, fexp2); ALU_CASE(flog2, flog2); ALU_CASE(f2i32, f2i); ALU_CASE(f2u32, f2u); ALU_CASE(i2f32, i2f); ALU_CASE(u2f32, u2f); ALU_CASE(fsin, fsin); ALU_CASE(fcos, fcos); /* Second op implicit #0 */ ALU_CASE(inot, inor); ALU_CASE(iand, iand); ALU_CASE(ior, ior); ALU_CASE(ixor, ixor); ALU_CASE(ishl, ishl); ALU_CASE(ishr, iasr); ALU_CASE(ushr, ilsr); ALU_CASE(b32all_fequal2, fball_eq); ALU_CASE(b32all_fequal3, fball_eq); ALU_CASE(b32all_fequal4, fball_eq); ALU_CASE(b32any_fnequal2, fbany_neq); ALU_CASE(b32any_fnequal3, fbany_neq); ALU_CASE(b32any_fnequal4, fbany_neq); ALU_CASE(b32all_iequal2, iball_eq); ALU_CASE(b32all_iequal3, iball_eq); ALU_CASE(b32all_iequal4, iball_eq); ALU_CASE(b32any_inequal2, ibany_neq); ALU_CASE(b32any_inequal3, ibany_neq); ALU_CASE(b32any_inequal4, ibany_neq); /* Source mods will be shoved in later */ ALU_CASE(fabs, fmov); ALU_CASE(fneg, fmov); ALU_CASE(fsat, fmov); /* For greater-or-equal, we lower to less-or-equal and flip the * arguments */ case nir_op_fge: case nir_op_fge32: case nir_op_ige32: case nir_op_uge32: { op = instr->op == nir_op_fge ? midgard_alu_op_fle : instr->op == nir_op_fge32 ? midgard_alu_op_fle : instr->op == nir_op_ige32 ? midgard_alu_op_ile : instr->op == nir_op_uge32 ? midgard_alu_op_ule : 0; /* Swap via temporary */ nir_alu_src temp = instr->src[1]; instr->src[1] = instr->src[0]; instr->src[0] = temp; break; } case nir_op_b32csel: { /* Midgard features both fcsel and icsel, depending on * the type of the arguments/output. However, as long * as we're careful we can _always_ use icsel and * _never_ need fcsel, since the latter does additional * floating-point-specific processing whereas the * former just moves bits on the wire. It's not obvious * why these are separate opcodes, save for the ability * to do things like sat/pos/abs/neg for free */ bool mixed = nir_is_non_scalar_swizzle(&instr->src[0], nr_components); op = mixed ? midgard_alu_op_icsel_v : midgard_alu_op_icsel; /* csel works as a two-arg in Midgard, since the condition is hardcoded in r31.w */ nr_inputs = 2; /* Emit the condition into r31 */ if (mixed) emit_condition_mixed(ctx, &instr->src[0], nr_components); else emit_condition(ctx, &instr->src[0].src, false, instr->src[0].swizzle[0]); /* The condition is the first argument; move the other * arguments up one to be a binary instruction for * Midgard */ memmove(instr->src, instr->src + 1, 2 * sizeof(nir_alu_src)); break; } default: DBG("Unhandled ALU op %s\n", nir_op_infos[instr->op].name); assert(0); return; } /* Midgard can perform certain modifiers on output of an ALU op */ unsigned outmod; if (midgard_is_integer_out_op(op)) { outmod = midgard_outmod_int_wrap; } else { bool sat = instr->dest.saturate || instr->op == nir_op_fsat; outmod = sat ? midgard_outmod_sat : midgard_outmod_none; } /* fmax(a, 0.0) can turn into a .pos modifier as an optimization */ if (instr->op == nir_op_fmax) { if (nir_is_fzero_constant(instr->src[0].src)) { op = midgard_alu_op_fmov; nr_inputs = 1; outmod = midgard_outmod_pos; instr->src[0] = instr->src[1]; } else if (nir_is_fzero_constant(instr->src[1].src)) { op = midgard_alu_op_fmov; nr_inputs = 1; outmod = midgard_outmod_pos; } } /* Fetch unit, quirks, etc information */ unsigned opcode_props = alu_opcode_props[op].props; bool quirk_flipped_r24 = opcode_props & QUIRK_FLIPPED_R24; /* src0 will always exist afaik, but src1 will not for 1-argument * instructions. The latter can only be fetched if the instruction * needs it, or else we may segfault. */ unsigned src0 = nir_alu_src_index(ctx, &instr->src[0]); unsigned src1 = nr_inputs == 2 ? nir_alu_src_index(ctx, &instr->src[1]) : SSA_UNUSED_0; /* Rather than use the instruction generation helpers, we do it * ourselves here to avoid the mess */ midgard_instruction ins = { .type = TAG_ALU_4, .ssa_args = { .src0 = quirk_flipped_r24 ? SSA_UNUSED_1 : src0, .src1 = quirk_flipped_r24 ? src0 : src1, .dest = dest, } }; nir_alu_src *nirmods[2] = { NULL }; if (nr_inputs == 2) { nirmods[0] = &instr->src[0]; nirmods[1] = &instr->src[1]; } else if (nr_inputs == 1) { nirmods[quirk_flipped_r24] = &instr->src[0]; } else { assert(0); } /* These were lowered to a move, so apply the corresponding mod */ if (instr->op == nir_op_fneg || instr->op == nir_op_fabs) { nir_alu_src *s = nirmods[quirk_flipped_r24]; if (instr->op == nir_op_fneg) s->negate = !s->negate; if (instr->op == nir_op_fabs) s->abs = !s->abs; } bool is_int = midgard_is_integer_op(op); midgard_vector_alu alu = { .op = op, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_none, .outmod = outmod, /* Writemask only valid for non-SSA NIR */ .mask = expand_writemask((1 << nr_components) - 1), .src1 = vector_alu_srco_unsigned(vector_alu_modifiers(nirmods[0], is_int)), .src2 = vector_alu_srco_unsigned(vector_alu_modifiers(nirmods[1], is_int)), }; /* Apply writemask if non-SSA, keeping in mind that we can't write to components that don't exist */ if (!is_ssa) alu.mask &= expand_writemask(instr->dest.write_mask); ins.alu = alu; /* Late fixup for emulated instructions */ if (instr->op == nir_op_b2f32 || instr->op == nir_op_b2i32) { /* Presently, our second argument is an inline #0 constant. * Switch over to an embedded 1.0 constant (that can't fit * inline, since we're 32-bit, not 16-bit like the inline * constants) */ ins.ssa_args.inline_constant = false; ins.ssa_args.src1 = SSA_FIXED_REGISTER(REGISTER_CONSTANT); ins.has_constants = true; if (instr->op == nir_op_b2f32) { ins.constants[0] = 1.0f; } else { /* Type pun it into place */ uint32_t one = 0x1; memcpy(&ins.constants[0], &one, sizeof(uint32_t)); } ins.alu.src2 = vector_alu_srco_unsigned(blank_alu_src_xxxx); } else if (nr_inputs == 1 && !quirk_flipped_r24) { /* Lots of instructions need a 0 plonked in */ ins.ssa_args.inline_constant = false; ins.ssa_args.src1 = SSA_FIXED_REGISTER(REGISTER_CONSTANT); ins.has_constants = true; ins.constants[0] = 0.0f; ins.alu.src2 = vector_alu_srco_unsigned(blank_alu_src_xxxx); } else if (instr->op == nir_op_inot) { /* ~b = ~(b & b), so duplicate the source */ ins.ssa_args.src1 = ins.ssa_args.src0; ins.alu.src2 = ins.alu.src1; } if ((opcode_props & UNITS_ALL) == UNIT_VLUT) { /* To avoid duplicating the lookup tables (probably), true LUT * instructions can only operate as if they were scalars. Lower * them here by changing the component. */ uint8_t original_swizzle[4]; memcpy(original_swizzle, nirmods[0]->swizzle, sizeof(nirmods[0]->swizzle)); for (int i = 0; i < nr_components; ++i) { ins.alu.mask = (0x3) << (2 * i); /* Mask the associated component */ for (int j = 0; j < 4; ++j) nirmods[0]->swizzle[j] = original_swizzle[i]; /* Pull from the correct component */ ins.alu.src1 = vector_alu_srco_unsigned(vector_alu_modifiers(nirmods[0], is_int)); emit_mir_instruction(ctx, ins); } } else { emit_mir_instruction(ctx, ins); } } #undef ALU_CASE static void emit_uniform_read(compiler_context *ctx, unsigned dest, unsigned offset, nir_src *indirect_offset) { /* TODO: half-floats */ if (!indirect_offset && offset < ctx->uniform_cutoff) { /* Fast path: For the first 16 uniforms, direct accesses are * 0-cycle, since they're just a register fetch in the usual * case. So, we alias the registers while we're still in * SSA-space */ int reg_slot = 23 - offset; alias_ssa(ctx, dest, SSA_FIXED_REGISTER(reg_slot)); } else { /* Otherwise, read from the 'special' UBO to access * higher-indexed uniforms, at a performance cost. More * generally, we're emitting a UBO read instruction. */ midgard_instruction ins = m_ld_uniform_32(dest, offset); /* TODO: Don't split */ ins.load_store.varying_parameters = (offset & 7) << 7; ins.load_store.address = offset >> 3; if (indirect_offset) { emit_indirect_offset(ctx, indirect_offset); ins.load_store.unknown = 0x8700; /* xxx: what is this? */ } else { ins.load_store.unknown = 0x1E00; /* xxx: what is this? */ } emit_mir_instruction(ctx, ins); } } static void emit_varying_read( compiler_context *ctx, unsigned dest, unsigned offset, unsigned nr_comp, unsigned component, nir_src *indirect_offset) { /* XXX: Half-floats? */ /* TODO: swizzle, mask */ midgard_instruction ins = m_ld_vary_32(dest, offset); ins.load_store.mask = (1 << nr_comp) - 1; ins.load_store.swizzle = SWIZZLE_XYZW >> (2 * component); midgard_varying_parameter p = { .is_varying = 1, .interpolation = midgard_interp_default, .flat = /*var->data.interpolation == INTERP_MODE_FLAT*/ 0 }; unsigned u; memcpy(&u, &p, sizeof(p)); ins.load_store.varying_parameters = u; if (indirect_offset) { /* We need to add in the dynamic index, moved to r27.w */ emit_indirect_offset(ctx, indirect_offset); ins.load_store.unknown = 0x79e; /* xxx: what is this? */ } else { /* Just a direct load */ ins.load_store.unknown = 0x1e9e; /* xxx: what is this? */ } emit_mir_instruction(ctx, ins); } static void emit_sysval_read(compiler_context *ctx, nir_intrinsic_instr *instr) { /* First, pull out the destination */ unsigned dest = nir_dest_index(ctx, &instr->dest); /* Now, figure out which uniform this is */ int sysval = midgard_nir_sysval_for_intrinsic(instr); void *val = _mesa_hash_table_u64_search(ctx->sysval_to_id, sysval); /* Sysvals are prefix uniforms */ unsigned uniform = ((uintptr_t) val) - 1; /* Emit the read itself -- this is never indirect */ emit_uniform_read(ctx, dest, uniform, NULL); } /* Reads RGBA8888 value from the tilebuffer and converts to a RGBA32F register, * using scalar ops functional on earlier Midgard generations. Newer Midgard * generations have faster vectorized reads. This operation is for blend * shaders in particular; reading the tilebuffer from the fragment shader * remains an open problem. */ static void emit_fb_read_blend_scalar(compiler_context *ctx, unsigned reg) { midgard_instruction ins = m_ld_color_buffer_8(reg, 0); ins.load_store.swizzle = 0; /* xxxx */ /* Read each component sequentially */ for (unsigned c = 0; c < 4; ++c) { ins.load_store.mask = (1 << c); ins.load_store.unknown = c; emit_mir_instruction(ctx, ins); } /* vadd.u2f hr2, zext(hr2), #0 */ midgard_vector_alu_src alu_src = blank_alu_src; alu_src.mod = midgard_int_zero_extend; alu_src.half = true; midgard_instruction u2f = { .type = TAG_ALU_4, .ssa_args = { .src0 = reg, .src1 = SSA_UNUSED_0, .dest = reg, .inline_constant = true }, .alu = { .op = midgard_alu_op_u2f, .reg_mode = midgard_reg_mode_16, .dest_override = midgard_dest_override_none, .mask = 0xF, .src1 = vector_alu_srco_unsigned(alu_src), .src2 = vector_alu_srco_unsigned(blank_alu_src), } }; emit_mir_instruction(ctx, u2f); /* vmul.fmul.sat r1, hr2, #0.00392151 */ alu_src.mod = 0; midgard_instruction fmul = { .type = TAG_ALU_4, .inline_constant = _mesa_float_to_half(1.0 / 255.0), .ssa_args = { .src0 = reg, .dest = reg, .src1 = SSA_UNUSED_0, .inline_constant = true }, .alu = { .op = midgard_alu_op_fmul, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_none, .outmod = midgard_outmod_sat, .mask = 0xFF, .src1 = vector_alu_srco_unsigned(alu_src), .src2 = vector_alu_srco_unsigned(blank_alu_src), } }; emit_mir_instruction(ctx, fmul); } static void emit_intrinsic(compiler_context *ctx, nir_intrinsic_instr *instr) { unsigned offset, reg; switch (instr->intrinsic) { case nir_intrinsic_discard_if: emit_condition(ctx, &instr->src[0], true, COMPONENT_X); /* fallthrough */ case nir_intrinsic_discard: { bool conditional = instr->intrinsic == nir_intrinsic_discard_if; struct midgard_instruction discard = v_branch(conditional, false); discard.branch.target_type = TARGET_DISCARD; emit_mir_instruction(ctx, discard); ctx->can_discard = true; break; } case nir_intrinsic_load_uniform: case nir_intrinsic_load_input: offset = nir_intrinsic_base(instr); unsigned nr_comp = nir_intrinsic_dest_components(instr); bool direct = nir_src_is_const(instr->src[0]); if (direct) { offset += nir_src_as_uint(instr->src[0]); } /* We may need to apply a fractional offset */ int component = instr->intrinsic == nir_intrinsic_load_input ? nir_intrinsic_component(instr) : 0; reg = nir_dest_index(ctx, &instr->dest); if (instr->intrinsic == nir_intrinsic_load_uniform && !ctx->is_blend) { emit_uniform_read(ctx, reg, ctx->sysval_count + offset, !direct ? &instr->src[0] : NULL); } else if (ctx->stage == MESA_SHADER_FRAGMENT && !ctx->is_blend) { emit_varying_read(ctx, reg, offset, nr_comp, component, !direct ? &instr->src[0] : NULL); } else if (ctx->is_blend) { /* For blend shaders, load the input color, which is * preloaded to r0 */ midgard_instruction move = v_fmov(reg, blank_alu_src, SSA_FIXED_REGISTER(0)); emit_mir_instruction(ctx, move); } else if (ctx->stage == MESA_SHADER_VERTEX) { midgard_instruction ins = m_ld_attr_32(reg, offset); ins.load_store.unknown = 0x1E1E; /* XXX: What is this? */ ins.load_store.mask = (1 << nr_comp) - 1; emit_mir_instruction(ctx, ins); } else { DBG("Unknown load\n"); assert(0); } break; case nir_intrinsic_load_output: assert(nir_src_is_const(instr->src[0])); reg = nir_dest_index(ctx, &instr->dest); if (ctx->is_blend) { /* TODO: MRT */ emit_fb_read_blend_scalar(ctx, reg); } else { DBG("Unknown output load\n"); assert(0); } break; case nir_intrinsic_load_blend_const_color_rgba: { assert(ctx->is_blend); reg = nir_dest_index(ctx, &instr->dest); /* Blend constants are embedded directly in the shader and * patched in, so we use some magic routing */ midgard_instruction ins = v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT), blank_alu_src, reg); ins.has_constants = true; ins.has_blend_constant = true; emit_mir_instruction(ctx, ins); break; } case nir_intrinsic_store_output: assert(nir_src_is_const(instr->src[1]) && "no indirect outputs"); offset = nir_intrinsic_base(instr) + nir_src_as_uint(instr->src[1]); reg = nir_src_index(ctx, &instr->src[0]); if (ctx->stage == MESA_SHADER_FRAGMENT) { /* gl_FragColor is not emitted with load/store * instructions. Instead, it gets plonked into * r0 at the end of the shader and we do the * framebuffer writeout dance. TODO: Defer * writes */ midgard_instruction move = v_fmov(reg, blank_alu_src, SSA_FIXED_REGISTER(0)); emit_mir_instruction(ctx, move); /* Save the index we're writing to for later reference * in the epilogue */ ctx->fragment_output = reg; } else if (ctx->stage == MESA_SHADER_VERTEX) { /* Varyings are written into one of two special * varying register, r26 or r27. The register itself is * selected as the register in the st_vary instruction, * minus the base of 26. E.g. write into r27 and then * call st_vary(1) */ midgard_instruction ins = v_fmov(reg, blank_alu_src, SSA_FIXED_REGISTER(26)); emit_mir_instruction(ctx, ins); /* We should have been vectorized. That also lets us * ignore the mask. because the mask component on * st_vary is (as far as I can tell) ignored [the blob * sets it to zero] */ assert(nir_intrinsic_component(instr) == 0); midgard_instruction st = m_st_vary_32(SSA_FIXED_REGISTER(0), offset); st.load_store.unknown = 0x1E9E; /* XXX: What is this? */ emit_mir_instruction(ctx, st); } else { DBG("Unknown store\n"); assert(0); } break; case nir_intrinsic_load_alpha_ref_float: assert(instr->dest.is_ssa); float ref_value = ctx->alpha_ref; float *v = ralloc_array(NULL, float, 4); memcpy(v, &ref_value, sizeof(float)); _mesa_hash_table_u64_insert(ctx->ssa_constants, instr->dest.ssa.index + 1, v); break; case nir_intrinsic_load_viewport_scale: case nir_intrinsic_load_viewport_offset: emit_sysval_read(ctx, instr); break; default: printf ("Unhandled intrinsic\n"); assert(0); break; } } static unsigned midgard_tex_format(enum glsl_sampler_dim dim) { switch (dim) { case GLSL_SAMPLER_DIM_2D: case GLSL_SAMPLER_DIM_EXTERNAL: return TEXTURE_2D; case GLSL_SAMPLER_DIM_3D: return TEXTURE_3D; case GLSL_SAMPLER_DIM_CUBE: return TEXTURE_CUBE; default: DBG("Unknown sampler dim type\n"); assert(0); return 0; } } static unsigned midgard_tex_op(nir_texop op) { switch (op) { case nir_texop_tex: case nir_texop_txb: return TEXTURE_OP_NORMAL; case nir_texop_txl: return TEXTURE_OP_LOD; default: unreachable("Unhanlded texture op"); } } static void emit_tex(compiler_context *ctx, nir_tex_instr *instr) { /* TODO */ //assert (!instr->sampler); //assert (!instr->texture_array_size); /* Allocate registers via a round robin scheme to alternate between the two registers */ int reg = ctx->texture_op_count & 1; int in_reg = reg, out_reg = reg; /* Make room for the reg */ if (ctx->texture_index[reg] > -1) unalias_ssa(ctx, ctx->texture_index[reg]); int texture_index = instr->texture_index; int sampler_index = texture_index; for (unsigned i = 0; i < instr->num_srcs; ++i) { int reg = SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE + in_reg); int index = nir_src_index(ctx, &instr->src[i].src); midgard_vector_alu_src alu_src = blank_alu_src; switch (instr->src[i].src_type) { case nir_tex_src_coord: { if (instr->sampler_dim == GLSL_SAMPLER_DIM_CUBE) { /* For cubemaps, we need to load coords into * special r27, and then use a special ld/st op * to select the face and copy the xy into the * texture register */ alu_src.swizzle = SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_Z, COMPONENT_X); midgard_instruction move = v_fmov(index, alu_src, SSA_FIXED_REGISTER(27)); emit_mir_instruction(ctx, move); midgard_instruction st = m_st_cubemap_coords(reg, 0); st.load_store.unknown = 0x24; /* XXX: What is this? */ st.load_store.mask = 0x3; /* xy */ st.load_store.swizzle = alu_src.swizzle; emit_mir_instruction(ctx, st); } else { alu_src.swizzle = SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_X, COMPONENT_X); midgard_instruction ins = v_fmov(index, alu_src, reg); ins.alu.mask = expand_writemask(0x3); /* xy */ emit_mir_instruction(ctx, ins); } break; } case nir_tex_src_bias: case nir_tex_src_lod: { /* To keep RA simple, we put the bias/LOD into the w * component of the input source, which is otherwise in xy */ alu_src.swizzle = SWIZZLE_XXXX; midgard_instruction ins = v_fmov(index, alu_src, reg); ins.alu.mask = expand_writemask(1 << COMPONENT_W); emit_mir_instruction(ctx, ins); break; }; default: unreachable("Unknown texture source type\n"); } } /* No helper to build texture words -- we do it all here */ midgard_instruction ins = { .type = TAG_TEXTURE_4, .texture = { .op = midgard_tex_op(instr->op), .format = midgard_tex_format(instr->sampler_dim), .texture_handle = texture_index, .sampler_handle = sampler_index, /* TODO: Regalloc it in */ .swizzle = SWIZZLE_XYZW, .mask = 0xF, /* TODO: half */ .in_reg_full = 1, .in_reg_swizzle = SWIZZLE_XYXX, .out_full = 1, /* Always 1 */ .unknown7 = 1, } }; /* Set registers to read and write from the same place */ ins.texture.in_reg_select = in_reg; ins.texture.out_reg_select = out_reg; /* Setup bias/LOD if necessary. Only register mode support right now. * TODO: Immediate mode for performance gains */ if (instr->op == nir_texop_txb || instr->op == nir_texop_txl) { ins.texture.lod_register = true; midgard_tex_register_select sel = { .select = in_reg, .full = 1, /* w */ .component_lo = 1, .component_hi = 1 }; uint8_t packed; memcpy(&packed, &sel, sizeof(packed)); ins.texture.bias = packed; } emit_mir_instruction(ctx, ins); /* Simultaneously alias the destination and emit a move for it. The move will be eliminated if possible */ int o_reg = REGISTER_TEXTURE_BASE + out_reg, o_index = nir_dest_index(ctx, &instr->dest); alias_ssa(ctx, o_index, SSA_FIXED_REGISTER(o_reg)); ctx->texture_index[reg] = o_index; midgard_instruction ins2 = v_fmov(SSA_FIXED_REGISTER(o_reg), blank_alu_src, o_index); emit_mir_instruction(ctx, ins2); /* Used for .cont and .last hinting */ ctx->texture_op_count++; } static void emit_jump(compiler_context *ctx, nir_jump_instr *instr) { switch (instr->type) { case nir_jump_break: { /* Emit a branch out of the loop */ struct midgard_instruction br = v_branch(false, false); br.branch.target_type = TARGET_BREAK; br.branch.target_break = ctx->current_loop_depth; emit_mir_instruction(ctx, br); DBG("break..\n"); break; } default: DBG("Unknown jump type %d\n", instr->type); break; } } static void emit_instr(compiler_context *ctx, struct nir_instr *instr) { switch (instr->type) { case nir_instr_type_load_const: emit_load_const(ctx, nir_instr_as_load_const(instr)); break; case nir_instr_type_intrinsic: emit_intrinsic(ctx, nir_instr_as_intrinsic(instr)); break; case nir_instr_type_alu: emit_alu(ctx, nir_instr_as_alu(instr)); break; case nir_instr_type_tex: emit_tex(ctx, nir_instr_as_tex(instr)); break; case nir_instr_type_jump: emit_jump(ctx, nir_instr_as_jump(instr)); break; case nir_instr_type_ssa_undef: /* Spurious */ break; default: DBG("Unhandled instruction type\n"); break; } } /* ALU instructions can inline or embed constants, which decreases register * pressure and saves space. */ #define CONDITIONAL_ATTACH(src) { \ void *entry = _mesa_hash_table_u64_search(ctx->ssa_constants, alu->ssa_args.src + 1); \ \ if (entry) { \ attach_constants(ctx, alu, entry, alu->ssa_args.src + 1); \ alu->ssa_args.src = SSA_FIXED_REGISTER(REGISTER_CONSTANT); \ } \ } static void inline_alu_constants(compiler_context *ctx) { mir_foreach_instr(ctx, alu) { /* Other instructions cannot inline constants */ if (alu->type != TAG_ALU_4) continue; /* If there is already a constant here, we can do nothing */ if (alu->has_constants) continue; /* It makes no sense to inline constants on a branch */ if (alu->compact_branch || alu->prepacked_branch) continue; CONDITIONAL_ATTACH(src0); if (!alu->has_constants) { CONDITIONAL_ATTACH(src1) } else if (!alu->inline_constant) { /* Corner case: _two_ vec4 constants, for instance with a * csel. For this case, we can only use a constant * register for one, we'll have to emit a move for the * other. Note, if both arguments are constants, then * necessarily neither argument depends on the value of * any particular register. As the destination register * will be wiped, that means we can spill the constant * to the destination register. */ void *entry = _mesa_hash_table_u64_search(ctx->ssa_constants, alu->ssa_args.src1 + 1); unsigned scratch = alu->ssa_args.dest; if (entry) { midgard_instruction ins = v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT), blank_alu_src, scratch); attach_constants(ctx, &ins, entry, alu->ssa_args.src1 + 1); /* Force a break XXX Defer r31 writes */ ins.unit = UNIT_VLUT; /* Set the source */ alu->ssa_args.src1 = scratch; /* Inject us -before- the last instruction which set r31 */ mir_insert_instruction_before(mir_prev_op(alu), ins); } } } } /* Midgard supports two types of constants, embedded constants (128-bit) and * inline constants (16-bit). Sometimes, especially with scalar ops, embedded * constants can be demoted to inline constants, for space savings and * sometimes a performance boost */ static void embedded_to_inline_constant(compiler_context *ctx) { mir_foreach_instr(ctx, ins) { if (!ins->has_constants) continue; if (ins->ssa_args.inline_constant) continue; /* Blend constants must not be inlined by definition */ if (ins->has_blend_constant) continue; /* src1 cannot be an inline constant due to encoding * restrictions. So, if possible we try to flip the arguments * in that case */ int op = ins->alu.op; if (ins->ssa_args.src0 == SSA_FIXED_REGISTER(REGISTER_CONSTANT)) { switch (op) { /* These ops require an operational change to flip * their arguments TODO */ case midgard_alu_op_flt: case midgard_alu_op_fle: case midgard_alu_op_ilt: case midgard_alu_op_ile: case midgard_alu_op_fcsel: case midgard_alu_op_icsel: DBG("Missed non-commutative flip (%s)\n", alu_opcode_props[op].name); default: break; } if (alu_opcode_props[op].props & OP_COMMUTES) { /* Flip the SSA numbers */ ins->ssa_args.src0 = ins->ssa_args.src1; ins->ssa_args.src1 = SSA_FIXED_REGISTER(REGISTER_CONSTANT); /* And flip the modifiers */ unsigned src_temp; src_temp = ins->alu.src2; ins->alu.src2 = ins->alu.src1; ins->alu.src1 = src_temp; } } if (ins->ssa_args.src1 == SSA_FIXED_REGISTER(REGISTER_CONSTANT)) { /* Extract the source information */ midgard_vector_alu_src *src; int q = ins->alu.src2; midgard_vector_alu_src *m = (midgard_vector_alu_src *) &q; src = m; /* Component is from the swizzle, e.g. r26.w -> w component. TODO: What if x is masked out? */ int component = src->swizzle & 3; /* Scale constant appropriately, if we can legally */ uint16_t scaled_constant = 0; if (midgard_is_integer_op(op)) { unsigned int *iconstants = (unsigned int *) ins->constants; scaled_constant = (uint16_t) iconstants[component]; /* Constant overflow after resize */ if (scaled_constant != iconstants[component]) continue; } else { float original = (float) ins->constants[component]; scaled_constant = _mesa_float_to_half(original); /* Check for loss of precision. If this is * mediump, we don't care, but for a highp * shader, we need to pay attention. NIR * doesn't yet tell us which mode we're in! * Practically this prevents most constants * from being inlined, sadly. */ float fp32 = _mesa_half_to_float(scaled_constant); if (fp32 != original) continue; } /* We don't know how to handle these with a constant */ if (src->mod || src->half || src->rep_low || src->rep_high) { DBG("Bailing inline constant...\n"); continue; } /* Make sure that the constant is not itself a * vector by checking if all accessed values * (by the swizzle) are the same. */ uint32_t *cons = (uint32_t *) ins->constants; uint32_t value = cons[component]; bool is_vector = false; unsigned mask = effective_writemask(&ins->alu); for (int c = 1; c < 4; ++c) { /* We only care if this component is actually used */ if (!(mask & (1 << c))) continue; uint32_t test = cons[(src->swizzle >> (2 * c)) & 3]; if (test != value) { is_vector = true; break; } } if (is_vector) continue; /* Get rid of the embedded constant */ ins->has_constants = false; ins->ssa_args.src1 = SSA_UNUSED_0; ins->ssa_args.inline_constant = true; ins->inline_constant = scaled_constant; } } } /* Map normal SSA sources to other SSA sources / fixed registers (like * uniforms) */ static void map_ssa_to_alias(compiler_context *ctx, int *ref) { /* Sign is used quite deliberately for unused */ if (*ref < 0) return; unsigned int alias = (uintptr_t) _mesa_hash_table_u64_search(ctx->ssa_to_alias, *ref + 1); if (alias) { /* Remove entry in leftovers to avoid a redunant fmov */ struct set_entry *leftover = _mesa_set_search(ctx->leftover_ssa_to_alias, ((void *) (uintptr_t) (*ref + 1))); if (leftover) _mesa_set_remove(ctx->leftover_ssa_to_alias, leftover); /* Assign the alias map */ *ref = alias - 1; return; } } /* Basic dead code elimination on the MIR itself, which cleans up e.g. the * texture pipeline */ static bool midgard_opt_dead_code_eliminate(compiler_context *ctx, midgard_block *block) { bool progress = false; mir_foreach_instr_in_block_safe(block, ins) { if (ins->type != TAG_ALU_4) continue; if (ins->compact_branch) continue; if (ins->ssa_args.dest >= SSA_FIXED_MINIMUM) continue; if (mir_is_live_after(ctx, block, ins, ins->ssa_args.dest)) continue; mir_remove_instruction(ins); progress = true; } return progress; } /* Dead code elimination for branches at the end of a block - only one branch * per block is legal semantically */ static void midgard_opt_cull_dead_branch(compiler_context *ctx, midgard_block *block) { bool branched = false; mir_foreach_instr_in_block_safe(block, ins) { if (!midgard_is_branch_unit(ins->unit)) continue; /* We ignore prepacked branches since the fragment epilogue is * just generally special */ if (ins->prepacked_branch) continue; /* Discards are similarly special and may not correspond to the * end of a block */ if (ins->branch.target_type == TARGET_DISCARD) continue; if (branched) { /* We already branched, so this is dead */ mir_remove_instruction(ins); } branched = true; } } static bool mir_nontrivial_mod(midgard_vector_alu_src src, bool is_int, unsigned mask) { /* abs or neg */ if (!is_int && src.mod) return true; /* swizzle */ for (unsigned c = 0; c < 4; ++c) { if (!(mask & (1 << c))) continue; if (((src.swizzle >> (2*c)) & 3) != c) return true; } return false; } static bool mir_nontrivial_source2_mod(midgard_instruction *ins) { unsigned mask = squeeze_writemask(ins->alu.mask); bool is_int = midgard_is_integer_op(ins->alu.op); midgard_vector_alu_src src2 = vector_alu_from_unsigned(ins->alu.src2); return mir_nontrivial_mod(src2, is_int, mask); } static bool mir_nontrivial_outmod(midgard_instruction *ins) { bool is_int = midgard_is_integer_op(ins->alu.op); unsigned mod = ins->alu.outmod; if (is_int) return mod != midgard_outmod_int_wrap; else return mod != midgard_outmod_none; } static bool midgard_opt_copy_prop(compiler_context *ctx, midgard_block *block) { bool progress = false; mir_foreach_instr_in_block_safe(block, ins) { if (ins->type != TAG_ALU_4) continue; if (!OP_IS_MOVE(ins->alu.op)) continue; unsigned from = ins->ssa_args.src1; unsigned to = ins->ssa_args.dest; /* We only work on pure SSA */ if (to >= SSA_FIXED_MINIMUM) continue; if (from >= SSA_FIXED_MINIMUM) continue; if (to >= ctx->func->impl->ssa_alloc) continue; if (from >= ctx->func->impl->ssa_alloc) continue; /* Constant propagation is not handled here, either */ if (ins->ssa_args.inline_constant) continue; if (ins->has_constants) continue; if (mir_nontrivial_source2_mod(ins)) continue; if (mir_nontrivial_outmod(ins)) continue; /* We're clear -- rewrite */ mir_rewrite_index_src(ctx, to, from); mir_remove_instruction(ins); progress |= true; } return progress; } /* fmov.pos is an idiom for fpos. Propoagate the .pos up to the source, so then * the move can be propagated away entirely */ static bool mir_compose_float_outmod(midgard_outmod_float *outmod, midgard_outmod_float comp) { /* Nothing to do */ if (comp == midgard_outmod_none) return true; if (*outmod == midgard_outmod_none) { *outmod = comp; return true; } /* TODO: Compose rules */ return false; } static bool midgard_opt_pos_propagate(compiler_context *ctx, midgard_block *block) { bool progress = false; mir_foreach_instr_in_block_safe(block, ins) { if (ins->type != TAG_ALU_4) continue; if (ins->alu.op != midgard_alu_op_fmov) continue; if (ins->alu.outmod != midgard_outmod_pos) continue; /* TODO: Registers? */ unsigned src = ins->ssa_args.src1; if (src >= ctx->func->impl->ssa_alloc) continue; assert(!mir_has_multiple_writes(ctx, src)); /* There might be a source modifier, too */ if (mir_nontrivial_source2_mod(ins)) continue; /* Backpropagate the modifier */ mir_foreach_instr_in_block_from_rev(block, v, mir_prev_op(ins)) { if (v->type != TAG_ALU_4) continue; if (v->ssa_args.dest != src) continue; /* Can we even take a float outmod? */ if (midgard_is_integer_out_op(v->alu.op)) continue; midgard_outmod_float temp = v->alu.outmod; progress |= mir_compose_float_outmod(&temp, ins->alu.outmod); /* Throw in the towel.. */ if (!progress) break; /* Otherwise, transfer the modifier */ v->alu.outmod = temp; ins->alu.outmod = midgard_outmod_none; break; } } return progress; } static bool midgard_opt_copy_prop_tex(compiler_context *ctx, midgard_block *block) { bool progress = false; mir_foreach_instr_in_block_safe(block, ins) { if (ins->type != TAG_ALU_4) continue; if (!OP_IS_MOVE(ins->alu.op)) continue; unsigned from = ins->ssa_args.src1; unsigned to = ins->ssa_args.dest; /* Make sure it's simple enough for us to handle */ if (from >= SSA_FIXED_MINIMUM) continue; if (from >= ctx->func->impl->ssa_alloc) continue; if (to < SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE)) continue; if (to > SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE + 1)) continue; bool eliminated = false; mir_foreach_instr_in_block_from_rev(block, v, mir_prev_op(ins)) { /* The texture registers are not SSA so be careful. * Conservatively, just stop if we hit a texture op * (even if it may not write) to where we are */ if (v->type != TAG_ALU_4) break; if (v->ssa_args.dest == from) { /* We don't want to track partial writes ... */ if (v->alu.mask == 0xF) { v->ssa_args.dest = to; eliminated = true; } break; } } if (eliminated) mir_remove_instruction(ins); progress |= eliminated; } return progress; } /* The following passes reorder MIR instructions to enable better scheduling */ static void midgard_pair_load_store(compiler_context *ctx, midgard_block *block) { mir_foreach_instr_in_block_safe(block, ins) { if (ins->type != TAG_LOAD_STORE_4) continue; /* We've found a load/store op. Check if next is also load/store. */ midgard_instruction *next_op = mir_next_op(ins); if (&next_op->link != &block->instructions) { if (next_op->type == TAG_LOAD_STORE_4) { /* If so, we're done since we're a pair */ ins = mir_next_op(ins); continue; } /* Maximum search distance to pair, to avoid register pressure disasters */ int search_distance = 8; /* Otherwise, we have an orphaned load/store -- search for another load */ mir_foreach_instr_in_block_from(block, c, mir_next_op(ins)) { /* Terminate search if necessary */ if (!(search_distance--)) break; if (c->type != TAG_LOAD_STORE_4) continue; /* Stores cannot be reordered, since they have * dependencies. For the same reason, indirect * loads cannot be reordered as their index is * loaded in r27.w */ if (OP_IS_STORE(c->load_store.op)) continue; /* It appears the 0x800 bit is set whenever a * load is direct, unset when it is indirect. * Skip indirect loads. */ if (!(c->load_store.unknown & 0x800)) continue; /* We found one! Move it up to pair and remove it from the old location */ mir_insert_instruction_before(ins, *c); mir_remove_instruction(c); break; } } } } /* If there are leftovers after the below pass, emit actual fmov * instructions for the slow-but-correct path */ static void emit_leftover_move(compiler_context *ctx) { set_foreach(ctx->leftover_ssa_to_alias, leftover) { int base = ((uintptr_t) leftover->key) - 1; int mapped = base; map_ssa_to_alias(ctx, &mapped); EMIT(fmov, mapped, blank_alu_src, base); } } static void actualise_ssa_to_alias(compiler_context *ctx) { mir_foreach_instr(ctx, ins) { map_ssa_to_alias(ctx, &ins->ssa_args.src0); map_ssa_to_alias(ctx, &ins->ssa_args.src1); } emit_leftover_move(ctx); } static void emit_fragment_epilogue(compiler_context *ctx) { /* Special case: writing out constants requires us to include the move * explicitly now, so shove it into r0 */ void *constant_value = _mesa_hash_table_u64_search(ctx->ssa_constants, ctx->fragment_output + 1); if (constant_value) { midgard_instruction ins = v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT), blank_alu_src, SSA_FIXED_REGISTER(0)); attach_constants(ctx, &ins, constant_value, ctx->fragment_output + 1); emit_mir_instruction(ctx, ins); } /* Perform the actual fragment writeout. We have two writeout/branch * instructions, forming a loop until writeout is successful as per the * docs. TODO: gl_FragDepth */ EMIT(alu_br_compact_cond, midgard_jmp_writeout_op_writeout, TAG_ALU_4, 0, midgard_condition_always); EMIT(alu_br_compact_cond, midgard_jmp_writeout_op_writeout, TAG_ALU_4, -1, midgard_condition_always); } /* For the blend epilogue, we need to convert the blended fragment vec4 (stored * in r0) to a RGBA8888 value by scaling and type converting. We then output it * with the int8 analogue to the fragment epilogue */ static void emit_blend_epilogue(compiler_context *ctx) { /* vmul.fmul.none.fulllow hr48, r0, #255 */ midgard_instruction scale = { .type = TAG_ALU_4, .unit = UNIT_VMUL, .inline_constant = _mesa_float_to_half(255.0), .ssa_args = { .src0 = SSA_FIXED_REGISTER(0), .src1 = SSA_UNUSED_0, .dest = SSA_FIXED_REGISTER(24), .inline_constant = true }, .alu = { .op = midgard_alu_op_fmul, .reg_mode = midgard_reg_mode_32, .dest_override = midgard_dest_override_lower, .mask = 0xFF, .src1 = vector_alu_srco_unsigned(blank_alu_src), .src2 = vector_alu_srco_unsigned(blank_alu_src), } }; emit_mir_instruction(ctx, scale); /* vadd.f2u8.pos.low hr0, hr48, #0 */ midgard_vector_alu_src alu_src = blank_alu_src; alu_src.half = true; midgard_instruction f2u8 = { .type = TAG_ALU_4, .ssa_args = { .src0 = SSA_FIXED_REGISTER(24), .src1 = SSA_UNUSED_0, .dest = SSA_FIXED_REGISTER(0), .inline_constant = true }, .alu = { .op = midgard_alu_op_f2u8, .reg_mode = midgard_reg_mode_16, .dest_override = midgard_dest_override_lower, .outmod = midgard_outmod_pos, .mask = 0xF, .src1 = vector_alu_srco_unsigned(alu_src), .src2 = vector_alu_srco_unsigned(blank_alu_src), } }; emit_mir_instruction(ctx, f2u8); /* vmul.imov.quarter r0, r0, r0 */ midgard_instruction imov_8 = { .type = TAG_ALU_4, .ssa_args = { .src0 = SSA_UNUSED_1, .src1 = SSA_FIXED_REGISTER(0), .dest = SSA_FIXED_REGISTER(0), }, .alu = { .op = midgard_alu_op_imov, .reg_mode = midgard_reg_mode_8, .dest_override = midgard_dest_override_none, .outmod = midgard_outmod_int_wrap, .mask = 0xFF, .src1 = vector_alu_srco_unsigned(blank_alu_src), .src2 = vector_alu_srco_unsigned(blank_alu_src), } }; /* Emit branch epilogue with the 8-bit move as the source */ emit_mir_instruction(ctx, imov_8); EMIT(alu_br_compact_cond, midgard_jmp_writeout_op_writeout, TAG_ALU_4, 0, midgard_condition_always); emit_mir_instruction(ctx, imov_8); EMIT(alu_br_compact_cond, midgard_jmp_writeout_op_writeout, TAG_ALU_4, -1, midgard_condition_always); } static midgard_block * emit_block(compiler_context *ctx, nir_block *block) { midgard_block *this_block = calloc(sizeof(midgard_block), 1); list_addtail(&this_block->link, &ctx->blocks); this_block->is_scheduled = false; ++ctx->block_count; ctx->texture_index[0] = -1; ctx->texture_index[1] = -1; /* Add us as a successor to the block we are following */ if (ctx->current_block) midgard_block_add_successor(ctx->current_block, this_block); /* Set up current block */ list_inithead(&this_block->instructions); ctx->current_block = this_block; nir_foreach_instr(instr, block) { emit_instr(ctx, instr); ++ctx->instruction_count; } inline_alu_constants(ctx); embedded_to_inline_constant(ctx); /* Perform heavylifting for aliasing */ actualise_ssa_to_alias(ctx); midgard_pair_load_store(ctx, this_block); /* Append fragment shader epilogue (value writeout) */ if (ctx->stage == MESA_SHADER_FRAGMENT) { if (block == nir_impl_last_block(ctx->func->impl)) { if (ctx->is_blend) emit_blend_epilogue(ctx); else emit_fragment_epilogue(ctx); } } if (block == nir_start_block(ctx->func->impl)) ctx->initial_block = this_block; if (block == nir_impl_last_block(ctx->func->impl)) ctx->final_block = this_block; /* Allow the next control flow to access us retroactively, for * branching etc */ ctx->current_block = this_block; /* Document the fallthrough chain */ ctx->previous_source_block = this_block; return this_block; } static midgard_block *emit_cf_list(struct compiler_context *ctx, struct exec_list *list); static void emit_if(struct compiler_context *ctx, nir_if *nif) { /* Conditional branches expect the condition in r31.w; emit a move for * that in the _previous_ block (which is the current block). */ emit_condition(ctx, &nif->condition, true, COMPONENT_X); /* Speculatively emit the branch, but we can't fill it in until later */ EMIT(branch, true, true); midgard_instruction *then_branch = mir_last_in_block(ctx->current_block); /* Emit the two subblocks */ midgard_block *then_block = emit_cf_list(ctx, &nif->then_list); /* Emit a jump from the end of the then block to the end of the else */ EMIT(branch, false, false); midgard_instruction *then_exit = mir_last_in_block(ctx->current_block); /* Emit second block, and check if it's empty */ int else_idx = ctx->block_count; int count_in = ctx->instruction_count; midgard_block *else_block = emit_cf_list(ctx, &nif->else_list); int after_else_idx = ctx->block_count; /* Now that we have the subblocks emitted, fix up the branches */ assert(then_block); assert(else_block); if (ctx->instruction_count == count_in) { /* The else block is empty, so don't emit an exit jump */ mir_remove_instruction(then_exit); then_branch->branch.target_block = after_else_idx; } else { then_branch->branch.target_block = else_idx; then_exit->branch.target_block = after_else_idx; } } static void emit_loop(struct compiler_context *ctx, nir_loop *nloop) { /* Remember where we are */ midgard_block *start_block = ctx->current_block; /* Allocate a loop number, growing the current inner loop depth */ int loop_idx = ++ctx->current_loop_depth; /* Get index from before the body so we can loop back later */ int start_idx = ctx->block_count; /* Emit the body itself */ emit_cf_list(ctx, &nloop->body); /* Branch back to loop back */ struct midgard_instruction br_back = v_branch(false, false); br_back.branch.target_block = start_idx; emit_mir_instruction(ctx, br_back); /* Mark down that branch in the graph. Note that we're really branching * to the block *after* we started in. TODO: Why doesn't the branch * itself have an off-by-one then...? */ midgard_block_add_successor(ctx->current_block, start_block->successors[0]); /* Find the index of the block about to follow us (note: we don't add * one; blocks are 0-indexed so we get a fencepost problem) */ int break_block_idx = ctx->block_count; /* Fix up the break statements we emitted to point to the right place, * now that we can allocate a block number for them */ list_for_each_entry_from(struct midgard_block, block, start_block, &ctx->blocks, link) { mir_foreach_instr_in_block(block, ins) { if (ins->type != TAG_ALU_4) continue; if (!ins->compact_branch) continue; if (ins->prepacked_branch) continue; /* We found a branch -- check the type to see if we need to do anything */ if (ins->branch.target_type != TARGET_BREAK) continue; /* It's a break! Check if it's our break */ if (ins->branch.target_break != loop_idx) continue; /* Okay, cool, we're breaking out of this loop. * Rewrite from a break to a goto */ ins->branch.target_type = TARGET_GOTO; ins->branch.target_block = break_block_idx; } } /* Now that we've finished emitting the loop, free up the depth again * so we play nice with recursion amid nested loops */ --ctx->current_loop_depth; } static midgard_block * emit_cf_list(struct compiler_context *ctx, struct exec_list *list) { midgard_block *start_block = NULL; foreach_list_typed(nir_cf_node, node, node, list) { switch (node->type) { case nir_cf_node_block: { midgard_block *block = emit_block(ctx, nir_cf_node_as_block(node)); if (!start_block) start_block = block; break; } case nir_cf_node_if: emit_if(ctx, nir_cf_node_as_if(node)); break; case nir_cf_node_loop: emit_loop(ctx, nir_cf_node_as_loop(node)); break; case nir_cf_node_function: assert(0); break; } } return start_block; } /* Due to lookahead, we need to report the first tag executed in the command * stream and in branch targets. An initial block might be empty, so iterate * until we find one that 'works' */ static unsigned midgard_get_first_tag_from_block(compiler_context *ctx, unsigned block_idx) { midgard_block *initial_block = mir_get_block(ctx, block_idx); unsigned first_tag = 0; do { midgard_bundle *initial_bundle = util_dynarray_element(&initial_block->bundles, midgard_bundle, 0); if (initial_bundle) { first_tag = initial_bundle->tag; break; } /* Initial block is empty, try the next block */ initial_block = list_first_entry(&(initial_block->link), midgard_block, link); } while(initial_block != NULL); assert(first_tag); return first_tag; } int midgard_compile_shader_nir(nir_shader *nir, midgard_program *program, bool is_blend) { struct util_dynarray *compiled = &program->compiled; midgard_debug = debug_get_option_midgard_debug(); compiler_context ictx = { .nir = nir, .stage = nir->info.stage, .is_blend = is_blend, .blend_constant_offset = -1, .alpha_ref = program->alpha_ref }; compiler_context *ctx = &ictx; /* TODO: Decide this at runtime */ ctx->uniform_cutoff = 8; /* Initialize at a global (not block) level hash tables */ ctx->ssa_constants = _mesa_hash_table_u64_create(NULL); ctx->ssa_to_alias = _mesa_hash_table_u64_create(NULL); ctx->hash_to_temp = _mesa_hash_table_u64_create(NULL); ctx->sysval_to_id = _mesa_hash_table_u64_create(NULL); ctx->leftover_ssa_to_alias = _mesa_set_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal); /* Record the varying mapping for the command stream's bookkeeping */ struct exec_list *varyings = ctx->stage == MESA_SHADER_VERTEX ? &nir->outputs : &nir->inputs; unsigned max_varying = 0; nir_foreach_variable(var, varyings) { unsigned loc = var->data.driver_location; unsigned sz = glsl_type_size(var->type, FALSE); for (int c = loc; c < (loc + sz); ++c) { program->varyings[c] = var->data.location; max_varying = MAX2(max_varying, c); } } /* Lower gl_Position pre-optimisation, but after lowering vars to ssa * (so we don't accidentally duplicate the epilogue since mesa/st has * messed with our I/O quite a bit already) */ NIR_PASS_V(nir, nir_lower_vars_to_ssa); if (ctx->stage == MESA_SHADER_VERTEX) NIR_PASS_V(nir, nir_lower_viewport_transform); NIR_PASS_V(nir, nir_lower_var_copies); NIR_PASS_V(nir, nir_lower_vars_to_ssa); NIR_PASS_V(nir, nir_split_var_copies); NIR_PASS_V(nir, nir_lower_var_copies); NIR_PASS_V(nir, nir_lower_global_vars_to_local); NIR_PASS_V(nir, nir_lower_var_copies); NIR_PASS_V(nir, nir_lower_vars_to_ssa); NIR_PASS_V(nir, nir_lower_io, nir_var_all, glsl_type_size, 0); /* Optimisation passes */ optimise_nir(nir); if (midgard_debug & MIDGARD_DBG_SHADERS) { nir_print_shader(nir, stdout); } /* Assign sysvals and counts, now that we're sure * (post-optimisation) */ midgard_nir_assign_sysvals(ctx, nir); program->uniform_count = nir->num_uniforms; program->sysval_count = ctx->sysval_count; memcpy(program->sysvals, ctx->sysvals, sizeof(ctx->sysvals[0]) * ctx->sysval_count); program->attribute_count = (ctx->stage == MESA_SHADER_VERTEX) ? nir->num_inputs : 0; program->varying_count = max_varying + 1; /* Fencepost off-by-one */ nir_foreach_function(func, nir) { if (!func->impl) continue; list_inithead(&ctx->blocks); ctx->block_count = 0; ctx->func = func; emit_cf_list(ctx, &func->impl->body); emit_block(ctx, func->impl->end_block); break; /* TODO: Multi-function shaders */ } util_dynarray_init(compiled, NULL); /* MIR-level optimizations */ bool progress = false; do { progress = false; mir_foreach_block(ctx, block) { progress |= midgard_opt_pos_propagate(ctx, block); progress |= midgard_opt_copy_prop(ctx, block); progress |= midgard_opt_copy_prop_tex(ctx, block); progress |= midgard_opt_dead_code_eliminate(ctx, block); } } while (progress); /* Nested control-flow can result in dead branches at the end of the * block. This messes with our analysis and is just dead code, so cull * them */ mir_foreach_block(ctx, block) { midgard_opt_cull_dead_branch(ctx, block); } /* Schedule! */ schedule_program(ctx); /* Now that all the bundles are scheduled and we can calculate block * sizes, emit actual branch instructions rather than placeholders */ int br_block_idx = 0; mir_foreach_block(ctx, block) { util_dynarray_foreach(&block->bundles, midgard_bundle, bundle) { for (int c = 0; c < bundle->instruction_count; ++c) { midgard_instruction *ins = bundle->instructions[c]; if (!midgard_is_branch_unit(ins->unit)) continue; if (ins->prepacked_branch) continue; /* Parse some basic branch info */ bool is_compact = ins->unit == ALU_ENAB_BR_COMPACT; bool is_conditional = ins->branch.conditional; bool is_inverted = ins->branch.invert_conditional; bool is_discard = ins->branch.target_type == TARGET_DISCARD; /* Determine the block we're jumping to */ int target_number = ins->branch.target_block; /* Report the destination tag */ int dest_tag = is_discard ? 0 : midgard_get_first_tag_from_block(ctx, target_number); /* Count up the number of quadwords we're * jumping over = number of quadwords until * (br_block_idx, target_number) */ int quadword_offset = 0; if (is_discard) { /* Jump to the end of the shader. We * need to include not only the * following blocks, but also the * contents of our current block (since * discard can come in the middle of * the block) */ midgard_block *blk = mir_get_block(ctx, br_block_idx + 1); for (midgard_bundle *bun = bundle + 1; bun < (midgard_bundle *)((char*) block->bundles.data + block->bundles.size); ++bun) { quadword_offset += quadword_size(bun->tag); } mir_foreach_block_from(ctx, blk, b) { quadword_offset += b->quadword_count; } } else if (target_number > br_block_idx) { /* Jump forward */ for (int idx = br_block_idx + 1; idx < target_number; ++idx) { midgard_block *blk = mir_get_block(ctx, idx); assert(blk); quadword_offset += blk->quadword_count; } } else { /* Jump backwards */ for (int idx = br_block_idx; idx >= target_number; --idx) { midgard_block *blk = mir_get_block(ctx, idx); assert(blk); quadword_offset -= blk->quadword_count; } } /* Unconditional extended branches (far jumps) * have issues, so we always use a conditional * branch, setting the condition to always for * unconditional. For compact unconditional * branches, cond isn't used so it doesn't * matter what we pick. */ midgard_condition cond = !is_conditional ? midgard_condition_always : is_inverted ? midgard_condition_false : midgard_condition_true; midgard_jmp_writeout_op op = is_discard ? midgard_jmp_writeout_op_discard : (is_compact && !is_conditional) ? midgard_jmp_writeout_op_branch_uncond : midgard_jmp_writeout_op_branch_cond; if (!is_compact) { midgard_branch_extended branch = midgard_create_branch_extended( cond, op, dest_tag, quadword_offset); memcpy(&ins->branch_extended, &branch, sizeof(branch)); } else if (is_conditional || is_discard) { midgard_branch_cond branch = { .op = op, .dest_tag = dest_tag, .offset = quadword_offset, .cond = cond }; assert(branch.offset == quadword_offset); memcpy(&ins->br_compact, &branch, sizeof(branch)); } else { assert(op == midgard_jmp_writeout_op_branch_uncond); midgard_branch_uncond branch = { .op = op, .dest_tag = dest_tag, .offset = quadword_offset, .unknown = 1 }; assert(branch.offset == quadword_offset); memcpy(&ins->br_compact, &branch, sizeof(branch)); } } } ++br_block_idx; } /* Emit flat binary from the instruction arrays. Iterate each block in * sequence. Save instruction boundaries such that lookahead tags can * be assigned easily */ /* Cache _all_ bundles in source order for lookahead across failed branches */ int bundle_count = 0; mir_foreach_block(ctx, block) { bundle_count += block->bundles.size / sizeof(midgard_bundle); } midgard_bundle **source_order_bundles = malloc(sizeof(midgard_bundle *) * bundle_count); int bundle_idx = 0; mir_foreach_block(ctx, block) { util_dynarray_foreach(&block->bundles, midgard_bundle, bundle) { source_order_bundles[bundle_idx++] = bundle; } } int current_bundle = 0; /* Midgard prefetches instruction types, so during emission we * need to lookahead. Unless this is the last instruction, in * which we return 1. Or if this is the second to last and the * last is an ALU, then it's also 1... */ mir_foreach_block(ctx, block) { mir_foreach_bundle_in_block(block, bundle) { int lookahead = 1; if (current_bundle + 1 < bundle_count) { uint8_t next = source_order_bundles[current_bundle + 1]->tag; if (!(current_bundle + 2 < bundle_count) && IS_ALU(next)) { lookahead = 1; } else { lookahead = next; } } emit_binary_bundle(ctx, bundle, compiled, lookahead); ++current_bundle; } /* TODO: Free deeper */ //util_dynarray_fini(&block->instructions); } free(source_order_bundles); /* Report the very first tag executed */ program->first_tag = midgard_get_first_tag_from_block(ctx, 0); /* Deal with off-by-one related to the fencepost problem */ program->work_register_count = ctx->work_registers + 1; program->can_discard = ctx->can_discard; program->uniform_cutoff = ctx->uniform_cutoff; program->blend_patch_offset = ctx->blend_constant_offset; if (midgard_debug & MIDGARD_DBG_SHADERS) disassemble_midgard(program->compiled.data, program->compiled.size); return 0; }