/* * Copyright © 2011 Intel Corporation * * 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 "brw_vec4.h" #include "brw_fs.h" #include "brw_cfg.h" #include "brw_vs.h" #include "brw_nir.h" #include "brw_vec4_builder.h" #include "brw_vec4_live_variables.h" #include "brw_dead_control_flow.h" #include "program/prog_parameter.h" #define MAX_INSTRUCTION (1 << 30) using namespace brw; namespace brw { void src_reg::init() { memset(this, 0, sizeof(*this)); this->file = BAD_FILE; } src_reg::src_reg(enum brw_reg_file file, int nr, const glsl_type *type) { init(); this->file = file; this->nr = nr; if (type && (type->is_scalar() || type->is_vector() || type->is_matrix())) this->swizzle = brw_swizzle_for_size(type->vector_elements); else this->swizzle = BRW_SWIZZLE_XYZW; if (type) this->type = brw_type_for_base_type(type); } /** Generic unset register constructor. */ src_reg::src_reg() { init(); } src_reg::src_reg(struct ::brw_reg reg) : backend_reg(reg) { this->offset = 0; this->reladdr = NULL; } src_reg::src_reg(const dst_reg ®) : backend_reg(reg) { this->reladdr = reg.reladdr; this->swizzle = brw_swizzle_for_mask(reg.writemask); } void dst_reg::init() { memset(this, 0, sizeof(*this)); this->file = BAD_FILE; this->writemask = WRITEMASK_XYZW; } dst_reg::dst_reg() { init(); } dst_reg::dst_reg(enum brw_reg_file file, int nr) { init(); this->file = file; this->nr = nr; } dst_reg::dst_reg(enum brw_reg_file file, int nr, const glsl_type *type, unsigned writemask) { init(); this->file = file; this->nr = nr; this->type = brw_type_for_base_type(type); this->writemask = writemask; } dst_reg::dst_reg(enum brw_reg_file file, int nr, brw_reg_type type, unsigned writemask) { init(); this->file = file; this->nr = nr; this->type = type; this->writemask = writemask; } dst_reg::dst_reg(struct ::brw_reg reg) : backend_reg(reg) { this->offset = 0; this->reladdr = NULL; } dst_reg::dst_reg(const src_reg ®) : backend_reg(reg) { this->writemask = brw_mask_for_swizzle(reg.swizzle); this->reladdr = reg.reladdr; } bool dst_reg::equals(const dst_reg &r) const { return (this->backend_reg::equals(r) && (reladdr == r.reladdr || (reladdr && r.reladdr && reladdr->equals(*r.reladdr)))); } bool vec4_instruction::is_send_from_grf() { switch (opcode) { case SHADER_OPCODE_SHADER_TIME_ADD: case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7: case SHADER_OPCODE_UNTYPED_ATOMIC: case SHADER_OPCODE_UNTYPED_SURFACE_READ: case SHADER_OPCODE_UNTYPED_SURFACE_WRITE: case SHADER_OPCODE_TYPED_ATOMIC: case SHADER_OPCODE_TYPED_SURFACE_READ: case SHADER_OPCODE_TYPED_SURFACE_WRITE: case VEC4_OPCODE_URB_READ: case TCS_OPCODE_URB_WRITE: case TCS_OPCODE_RELEASE_INPUT: case SHADER_OPCODE_BARRIER: return true; default: return false; } } /** * Returns true if this instruction's sources and destinations cannot * safely be the same register. * * In most cases, a register can be written over safely by the same * instruction that is its last use. For a single instruction, the * sources are dereferenced before writing of the destination starts * (naturally). * * However, there are a few cases where this can be problematic: * * - Virtual opcodes that translate to multiple instructions in the * code generator: if src == dst and one instruction writes the * destination before a later instruction reads the source, then * src will have been clobbered. * * The register allocator uses this information to set up conflicts between * GRF sources and the destination. */ bool vec4_instruction::has_source_and_destination_hazard() const { switch (opcode) { case TCS_OPCODE_SET_INPUT_URB_OFFSETS: case TCS_OPCODE_SET_OUTPUT_URB_OFFSETS: case TES_OPCODE_ADD_INDIRECT_URB_OFFSET: return true; default: return false; } } unsigned vec4_instruction::regs_read(unsigned arg) const { if (src[arg].file == BAD_FILE) return 0; switch (opcode) { case SHADER_OPCODE_SHADER_TIME_ADD: case SHADER_OPCODE_UNTYPED_ATOMIC: case SHADER_OPCODE_UNTYPED_SURFACE_READ: case SHADER_OPCODE_UNTYPED_SURFACE_WRITE: case SHADER_OPCODE_TYPED_ATOMIC: case SHADER_OPCODE_TYPED_SURFACE_READ: case SHADER_OPCODE_TYPED_SURFACE_WRITE: case TCS_OPCODE_URB_WRITE: return arg == 0 ? mlen : 1; case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7: return arg == 1 ? mlen : 1; default: return 1; } } bool vec4_instruction::can_do_source_mods(const struct gen_device_info *devinfo) { if (devinfo->gen == 6 && is_math()) return false; if (is_send_from_grf()) return false; if (!backend_instruction::can_do_source_mods()) return false; return true; } bool vec4_instruction::can_do_writemask(const struct gen_device_info *devinfo) { switch (opcode) { case SHADER_OPCODE_GEN4_SCRATCH_READ: case VS_OPCODE_PULL_CONSTANT_LOAD: case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7: case VS_OPCODE_SET_SIMD4X2_HEADER_GEN9: case TCS_OPCODE_SET_INPUT_URB_OFFSETS: case TCS_OPCODE_SET_OUTPUT_URB_OFFSETS: case TES_OPCODE_CREATE_INPUT_READ_HEADER: case TES_OPCODE_ADD_INDIRECT_URB_OFFSET: case VEC4_OPCODE_URB_READ: case SHADER_OPCODE_MOV_INDIRECT: return false; default: /* The MATH instruction on Gen6 only executes in align1 mode, which does * not support writemasking. */ if (devinfo->gen == 6 && is_math()) return false; if (is_tex()) return false; return true; } } bool vec4_instruction::can_change_types() const { return dst.type == src[0].type && !src[0].abs && !src[0].negate && !saturate && (opcode == BRW_OPCODE_MOV || (opcode == BRW_OPCODE_SEL && dst.type == src[1].type && predicate != BRW_PREDICATE_NONE && !src[1].abs && !src[1].negate)); } /** * Returns how many MRFs an opcode will write over. * * Note that this is not the 0 or 1 implied writes in an actual gen * instruction -- the generate_* functions generate additional MOVs * for setup. */ int vec4_visitor::implied_mrf_writes(vec4_instruction *inst) { if (inst->mlen == 0 || inst->is_send_from_grf()) return 0; switch (inst->opcode) { case SHADER_OPCODE_RCP: case SHADER_OPCODE_RSQ: case SHADER_OPCODE_SQRT: case SHADER_OPCODE_EXP2: case SHADER_OPCODE_LOG2: case SHADER_OPCODE_SIN: case SHADER_OPCODE_COS: return 1; case SHADER_OPCODE_INT_QUOTIENT: case SHADER_OPCODE_INT_REMAINDER: case SHADER_OPCODE_POW: case TCS_OPCODE_THREAD_END: return 2; case VS_OPCODE_URB_WRITE: return 1; case VS_OPCODE_PULL_CONSTANT_LOAD: return 2; case SHADER_OPCODE_GEN4_SCRATCH_READ: return 2; case SHADER_OPCODE_GEN4_SCRATCH_WRITE: return 3; case GS_OPCODE_URB_WRITE: case GS_OPCODE_URB_WRITE_ALLOCATE: case GS_OPCODE_THREAD_END: return 0; case GS_OPCODE_FF_SYNC: return 1; case TCS_OPCODE_URB_WRITE: return 0; case SHADER_OPCODE_SHADER_TIME_ADD: return 0; case SHADER_OPCODE_TEX: case SHADER_OPCODE_TXL: case SHADER_OPCODE_TXD: case SHADER_OPCODE_TXF: case SHADER_OPCODE_TXF_CMS: case SHADER_OPCODE_TXF_CMS_W: case SHADER_OPCODE_TXF_MCS: case SHADER_OPCODE_TXS: case SHADER_OPCODE_TG4: case SHADER_OPCODE_TG4_OFFSET: case SHADER_OPCODE_SAMPLEINFO: case VS_OPCODE_GET_BUFFER_SIZE: return inst->header_size; default: unreachable("not reached"); } } bool src_reg::equals(const src_reg &r) const { return (this->backend_reg::equals(r) && !reladdr && !r.reladdr); } bool vec4_visitor::opt_vector_float() { bool progress = false; foreach_block(block, cfg) { int last_reg = -1, last_reg_offset = -1; enum brw_reg_file last_reg_file = BAD_FILE; uint8_t imm[4] = { 0 }; int inst_count = 0; vec4_instruction *imm_inst[4]; unsigned writemask = 0; enum brw_reg_type dest_type = BRW_REGISTER_TYPE_F; foreach_inst_in_block_safe(vec4_instruction, inst, block) { int vf = -1; enum brw_reg_type need_type; /* Look for unconditional MOVs from an immediate with a partial * writemask. Skip type-conversion MOVs other than integer 0, * where the type doesn't matter. See if the immediate can be * represented as a VF. */ if (inst->opcode == BRW_OPCODE_MOV && inst->src[0].file == IMM && inst->predicate == BRW_PREDICATE_NONE && inst->dst.writemask != WRITEMASK_XYZW && (inst->src[0].type == inst->dst.type || inst->src[0].d == 0)) { vf = brw_float_to_vf(inst->src[0].d); need_type = BRW_REGISTER_TYPE_D; if (vf == -1) { vf = brw_float_to_vf(inst->src[0].f); need_type = BRW_REGISTER_TYPE_F; } } else { last_reg = -1; } /* If this wasn't a MOV, or the destination register doesn't match, * or we have to switch destination types, then this breaks our * sequence. Combine anything we've accumulated so far. */ if (last_reg != inst->dst.nr || last_reg_offset != inst->dst.offset / REG_SIZE || last_reg_file != inst->dst.file || (vf > 0 && dest_type != need_type)) { if (inst_count > 1) { unsigned vf; memcpy(&vf, imm, sizeof(vf)); vec4_instruction *mov = MOV(imm_inst[0]->dst, brw_imm_vf(vf)); mov->dst.type = dest_type; mov->dst.writemask = writemask; inst->insert_before(block, mov); for (int i = 0; i < inst_count; i++) { imm_inst[i]->remove(block); } progress = true; } inst_count = 0; last_reg = -1; writemask = 0; dest_type = BRW_REGISTER_TYPE_F; for (int i = 0; i < 4; i++) { imm[i] = 0; } } /* Record this instruction's value (if it was representable). */ if (vf != -1) { if ((inst->dst.writemask & WRITEMASK_X) != 0) imm[0] = vf; if ((inst->dst.writemask & WRITEMASK_Y) != 0) imm[1] = vf; if ((inst->dst.writemask & WRITEMASK_Z) != 0) imm[2] = vf; if ((inst->dst.writemask & WRITEMASK_W) != 0) imm[3] = vf; writemask |= inst->dst.writemask; imm_inst[inst_count++] = inst; last_reg = inst->dst.nr; last_reg_offset = inst->dst.offset / REG_SIZE; last_reg_file = inst->dst.file; if (vf > 0) dest_type = need_type; } } } if (progress) invalidate_live_intervals(); return progress; } /* Replaces unused channels of a swizzle with channels that are used. * * For instance, this pass transforms * * mov vgrf4.yz, vgrf5.wxzy * * into * * mov vgrf4.yz, vgrf5.xxzx * * This eliminates false uses of some channels, letting dead code elimination * remove the instructions that wrote them. */ bool vec4_visitor::opt_reduce_swizzle() { bool progress = false; foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) { if (inst->dst.file == BAD_FILE || inst->dst.file == ARF || inst->dst.file == FIXED_GRF || inst->is_send_from_grf()) continue; unsigned swizzle; /* Determine which channels of the sources are read. */ switch (inst->opcode) { case VEC4_OPCODE_PACK_BYTES: case BRW_OPCODE_DP4: case BRW_OPCODE_DPH: /* FINISHME: DPH reads only three channels of src0, * but all four of src1. */ swizzle = brw_swizzle_for_size(4); break; case BRW_OPCODE_DP3: swizzle = brw_swizzle_for_size(3); break; case BRW_OPCODE_DP2: swizzle = brw_swizzle_for_size(2); break; default: swizzle = brw_swizzle_for_mask(inst->dst.writemask); break; } /* Update sources' swizzles. */ for (int i = 0; i < 3; i++) { if (inst->src[i].file != VGRF && inst->src[i].file != ATTR && inst->src[i].file != UNIFORM) continue; const unsigned new_swizzle = brw_compose_swizzle(swizzle, inst->src[i].swizzle); if (inst->src[i].swizzle != new_swizzle) { inst->src[i].swizzle = new_swizzle; progress = true; } } } if (progress) invalidate_live_intervals(); return progress; } void vec4_visitor::split_uniform_registers() { /* Prior to this, uniforms have been in an array sized according to * the number of vector uniforms present, sparsely filled (so an * aggregate results in reg indices being skipped over). Now we're * going to cut those aggregates up so each .nr index is one * vector. The goal is to make elimination of unused uniform * components easier later. */ foreach_block_and_inst(block, vec4_instruction, inst, cfg) { for (int i = 0 ; i < 3; i++) { if (inst->src[i].file != UNIFORM) continue; assert(!inst->src[i].reladdr); inst->src[i].nr += inst->src[i].offset / 16; inst->src[i].offset %= 16; } } } void vec4_visitor::pack_uniform_registers() { uint8_t chans_used[this->uniforms]; int new_loc[this->uniforms]; int new_chan[this->uniforms]; memset(chans_used, 0, sizeof(chans_used)); memset(new_loc, 0, sizeof(new_loc)); memset(new_chan, 0, sizeof(new_chan)); /* Find which uniform vectors are actually used by the program. We * expect unused vector elements when we've moved array access out * to pull constants, and from some GLSL code generators like wine. */ foreach_block_and_inst(block, vec4_instruction, inst, cfg) { unsigned readmask; switch (inst->opcode) { case VEC4_OPCODE_PACK_BYTES: case BRW_OPCODE_DP4: case BRW_OPCODE_DPH: readmask = 0xf; break; case BRW_OPCODE_DP3: readmask = 0x7; break; case BRW_OPCODE_DP2: readmask = 0x3; break; default: readmask = inst->dst.writemask; break; } for (int i = 0 ; i < 3; i++) { if (inst->src[i].file != UNIFORM) continue; int reg = inst->src[i].nr; for (int c = 0; c < 4; c++) { if (!(readmask & (1 << c))) continue; chans_used[reg] = MAX2(chans_used[reg], BRW_GET_SWZ(inst->src[i].swizzle, c) + 1); } } if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT && inst->src[0].file == UNIFORM) { assert(inst->src[2].file == BRW_IMMEDIATE_VALUE); assert(inst->src[0].subnr == 0); unsigned bytes_read = inst->src[2].ud; assert(bytes_read % 4 == 0); unsigned vec4s_read = DIV_ROUND_UP(bytes_read, 16); /* We just mark every register touched by a MOV_INDIRECT as being * fully used. This ensures that it doesn't broken up piecewise by * the next part of our packing algorithm. */ int reg = inst->src[0].nr; for (unsigned i = 0; i < vec4s_read; i++) chans_used[reg + i] = 4; } } int new_uniform_count = 0; /* Now, figure out a packing of the live uniform vectors into our * push constants. */ for (int src = 0; src < uniforms; src++) { int size = chans_used[src]; if (size == 0) continue; int dst; /* Find the lowest place we can slot this uniform in. */ for (dst = 0; dst < src; dst++) { if (chans_used[dst] + size <= 4) break; } if (src == dst) { new_loc[src] = dst; new_chan[src] = 0; } else { new_loc[src] = dst; new_chan[src] = chans_used[dst]; /* Move the references to the data */ for (int j = 0; j < size; j++) { stage_prog_data->param[dst * 4 + new_chan[src] + j] = stage_prog_data->param[src * 4 + j]; } chans_used[dst] += size; chans_used[src] = 0; } new_uniform_count = MAX2(new_uniform_count, dst + 1); } this->uniforms = new_uniform_count; /* Now, update the instructions for our repacked uniforms. */ foreach_block_and_inst(block, vec4_instruction, inst, cfg) { for (int i = 0 ; i < 3; i++) { int src = inst->src[i].nr; if (inst->src[i].file != UNIFORM) continue; inst->src[i].nr = new_loc[src]; inst->src[i].swizzle += BRW_SWIZZLE4(new_chan[src], new_chan[src], new_chan[src], new_chan[src]); } } } /** * Does algebraic optimizations (0 * a = 0, 1 * a = a, a + 0 = a). * * While GLSL IR also performs this optimization, we end up with it in * our instruction stream for a couple of reasons. One is that we * sometimes generate silly instructions, for example in array access * where we'll generate "ADD offset, index, base" even if base is 0. * The other is that GLSL IR's constant propagation doesn't track the * components of aggregates, so some VS patterns (initialize matrix to * 0, accumulate in vertex blending factors) end up breaking down to * instructions involving 0. */ bool vec4_visitor::opt_algebraic() { bool progress = false; foreach_block_and_inst(block, vec4_instruction, inst, cfg) { switch (inst->opcode) { case BRW_OPCODE_MOV: if (inst->src[0].file != IMM) break; if (inst->saturate) { if (inst->dst.type != inst->src[0].type) assert(!"unimplemented: saturate mixed types"); if (brw_saturate_immediate(inst->dst.type, &inst->src[0].as_brw_reg())) { inst->saturate = false; progress = true; } } break; case VEC4_OPCODE_UNPACK_UNIFORM: if (inst->src[0].file != UNIFORM) { inst->opcode = BRW_OPCODE_MOV; progress = true; } break; case BRW_OPCODE_ADD: if (inst->src[1].is_zero()) { inst->opcode = BRW_OPCODE_MOV; inst->src[1] = src_reg(); progress = true; } break; case BRW_OPCODE_MUL: if (inst->src[1].is_zero()) { inst->opcode = BRW_OPCODE_MOV; switch (inst->src[0].type) { case BRW_REGISTER_TYPE_F: inst->src[0] = brw_imm_f(0.0f); break; case BRW_REGISTER_TYPE_D: inst->src[0] = brw_imm_d(0); break; case BRW_REGISTER_TYPE_UD: inst->src[0] = brw_imm_ud(0u); break; default: unreachable("not reached"); } inst->src[1] = src_reg(); progress = true; } else if (inst->src[1].is_one()) { inst->opcode = BRW_OPCODE_MOV; inst->src[1] = src_reg(); progress = true; } else if (inst->src[1].is_negative_one()) { inst->opcode = BRW_OPCODE_MOV; inst->src[0].negate = !inst->src[0].negate; inst->src[1] = src_reg(); progress = true; } break; case BRW_OPCODE_CMP: if (inst->conditional_mod == BRW_CONDITIONAL_GE && inst->src[0].abs && inst->src[0].negate && inst->src[1].is_zero()) { inst->src[0].abs = false; inst->src[0].negate = false; inst->conditional_mod = BRW_CONDITIONAL_Z; progress = true; break; } break; case SHADER_OPCODE_BROADCAST: if (is_uniform(inst->src[0]) || inst->src[1].is_zero()) { inst->opcode = BRW_OPCODE_MOV; inst->src[1] = src_reg(); inst->force_writemask_all = true; progress = true; } break; default: break; } } if (progress) invalidate_live_intervals(); return progress; } /** * Only a limited number of hardware registers may be used for push * constants, so this turns access to the overflowed constants into * pull constants. */ void vec4_visitor::move_push_constants_to_pull_constants() { int pull_constant_loc[this->uniforms]; /* Only allow 32 registers (256 uniform components) as push constants, * which is the limit on gen6. * * If changing this value, note the limitation about total_regs in * brw_curbe.c. */ int max_uniform_components = 32 * 8; if (this->uniforms * 4 <= max_uniform_components) return; /* Make some sort of choice as to which uniforms get sent to pull * constants. We could potentially do something clever here like * look for the most infrequently used uniform vec4s, but leave * that for later. */ for (int i = 0; i < this->uniforms * 4; i += 4) { pull_constant_loc[i / 4] = -1; if (i >= max_uniform_components) { const gl_constant_value **values = &stage_prog_data->param[i]; /* Try to find an existing copy of this uniform in the pull * constants if it was part of an array access already. */ for (unsigned int j = 0; j < stage_prog_data->nr_pull_params; j += 4) { int matches; for (matches = 0; matches < 4; matches++) { if (stage_prog_data->pull_param[j + matches] != values[matches]) break; } if (matches == 4) { pull_constant_loc[i / 4] = j / 4; break; } } if (pull_constant_loc[i / 4] == -1) { assert(stage_prog_data->nr_pull_params % 4 == 0); pull_constant_loc[i / 4] = stage_prog_data->nr_pull_params / 4; for (int j = 0; j < 4; j++) { stage_prog_data->pull_param[stage_prog_data->nr_pull_params++] = values[j]; } } } } /* Now actually rewrite usage of the things we've moved to pull * constants. */ foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) { for (int i = 0 ; i < 3; i++) { if (inst->src[i].file != UNIFORM || pull_constant_loc[inst->src[i].nr] == -1) continue; int uniform = inst->src[i].nr; dst_reg temp = dst_reg(this, glsl_type::vec4_type); emit_pull_constant_load(block, inst, temp, inst->src[i], pull_constant_loc[uniform], src_reg()); inst->src[i].file = temp.file; inst->src[i].nr = temp.nr; inst->src[i].offset %= 16; inst->src[i].reladdr = NULL; } } /* Repack push constants to remove the now-unused ones. */ pack_uniform_registers(); } /* Conditions for which we want to avoid setting the dependency control bits */ bool vec4_visitor::is_dep_ctrl_unsafe(const vec4_instruction *inst) { #define IS_DWORD(reg) \ (reg.type == BRW_REGISTER_TYPE_UD || \ reg.type == BRW_REGISTER_TYPE_D) /* "When source or destination datatype is 64b or operation is integer DWord * multiply, DepCtrl must not be used." * May apply to future SoCs as well. */ if (devinfo->is_cherryview) { if (inst->opcode == BRW_OPCODE_MUL && IS_DWORD(inst->src[0]) && IS_DWORD(inst->src[1])) return true; } #undef IS_DWORD if (devinfo->gen >= 8) { if (inst->opcode == BRW_OPCODE_F32TO16) return true; } /* * mlen: * In the presence of send messages, totally interrupt dependency * control. They're long enough that the chance of dependency * control around them just doesn't matter. * * predicate: * From the Ivy Bridge PRM, volume 4 part 3.7, page 80: * When a sequence of NoDDChk and NoDDClr are used, the last instruction that * completes the scoreboard clear must have a non-zero execution mask. This * means, if any kind of predication can change the execution mask or channel * enable of the last instruction, the optimization must be avoided. This is * to avoid instructions being shot down the pipeline when no writes are * required. * * math: * Dependency control does not work well over math instructions. * NB: Discovered empirically */ return (inst->mlen || inst->predicate || inst->is_math()); } /** * Sets the dependency control fields on instructions after register * allocation and before the generator is run. * * When you have a sequence of instructions like: * * DP4 temp.x vertex uniform[0] * DP4 temp.y vertex uniform[0] * DP4 temp.z vertex uniform[0] * DP4 temp.w vertex uniform[0] * * The hardware doesn't know that it can actually run the later instructions * while the previous ones are in flight, producing stalls. However, we have * manual fields we can set in the instructions that let it do so. */ void vec4_visitor::opt_set_dependency_control() { vec4_instruction *last_grf_write[BRW_MAX_GRF]; uint8_t grf_channels_written[BRW_MAX_GRF]; vec4_instruction *last_mrf_write[BRW_MAX_GRF]; uint8_t mrf_channels_written[BRW_MAX_GRF]; assert(prog_data->total_grf || !"Must be called after register allocation"); foreach_block (block, cfg) { memset(last_grf_write, 0, sizeof(last_grf_write)); memset(last_mrf_write, 0, sizeof(last_mrf_write)); foreach_inst_in_block (vec4_instruction, inst, block) { /* If we read from a register that we were doing dependency control * on, don't do dependency control across the read. */ for (int i = 0; i < 3; i++) { int reg = inst->src[i].nr + inst->src[i].offset / REG_SIZE; if (inst->src[i].file == VGRF) { last_grf_write[reg] = NULL; } else if (inst->src[i].file == FIXED_GRF) { memset(last_grf_write, 0, sizeof(last_grf_write)); break; } assert(inst->src[i].file != MRF); } if (is_dep_ctrl_unsafe(inst)) { memset(last_grf_write, 0, sizeof(last_grf_write)); memset(last_mrf_write, 0, sizeof(last_mrf_write)); continue; } /* Now, see if we can do dependency control for this instruction * against a previous one writing to its destination. */ int reg = inst->dst.nr + inst->dst.offset / REG_SIZE; if (inst->dst.file == VGRF || inst->dst.file == FIXED_GRF) { if (last_grf_write[reg] && !(inst->dst.writemask & grf_channels_written[reg])) { last_grf_write[reg]->no_dd_clear = true; inst->no_dd_check = true; } else { grf_channels_written[reg] = 0; } last_grf_write[reg] = inst; grf_channels_written[reg] |= inst->dst.writemask; } else if (inst->dst.file == MRF) { if (last_mrf_write[reg] && !(inst->dst.writemask & mrf_channels_written[reg])) { last_mrf_write[reg]->no_dd_clear = true; inst->no_dd_check = true; } else { mrf_channels_written[reg] = 0; } last_mrf_write[reg] = inst; mrf_channels_written[reg] |= inst->dst.writemask; } } } } bool vec4_instruction::can_reswizzle(const struct gen_device_info *devinfo, int dst_writemask, int swizzle, int swizzle_mask) { /* Gen6 MATH instructions can not execute in align16 mode, so swizzles * are not allowed. */ if (devinfo->gen == 6 && is_math() && swizzle != BRW_SWIZZLE_XYZW) return false; if (!can_do_writemask(devinfo) && dst_writemask != WRITEMASK_XYZW) return false; /* If this instruction sets anything not referenced by swizzle, then we'd * totally break it when we reswizzle. */ if (dst.writemask & ~swizzle_mask) return false; if (mlen > 0) return false; for (int i = 0; i < 3; i++) { if (src[i].is_accumulator()) return false; } return true; } /** * For any channels in the swizzle's source that were populated by this * instruction, rewrite the instruction to put the appropriate result directly * in those channels. * * e.g. for swizzle=yywx, MUL a.xy b c -> MUL a.yy_x b.yy z.yy_x */ void vec4_instruction::reswizzle(int dst_writemask, int swizzle) { /* Destination write mask doesn't correspond to source swizzle for the dot * product and pack_bytes instructions. */ if (opcode != BRW_OPCODE_DP4 && opcode != BRW_OPCODE_DPH && opcode != BRW_OPCODE_DP3 && opcode != BRW_OPCODE_DP2 && opcode != VEC4_OPCODE_PACK_BYTES) { for (int i = 0; i < 3; i++) { if (src[i].file == BAD_FILE || src[i].file == IMM) continue; src[i].swizzle = brw_compose_swizzle(swizzle, src[i].swizzle); } } /* Apply the specified swizzle and writemask to the original mask of * written components. */ dst.writemask = dst_writemask & brw_apply_swizzle_to_mask(swizzle, dst.writemask); } /* * Tries to reduce extra MOV instructions by taking temporary GRFs that get * just written and then MOVed into another reg and making the original write * of the GRF write directly to the final destination instead. */ bool vec4_visitor::opt_register_coalesce() { bool progress = false; int next_ip = 0; calculate_live_intervals(); foreach_block_and_inst_safe (block, vec4_instruction, inst, cfg) { int ip = next_ip; next_ip++; if (inst->opcode != BRW_OPCODE_MOV || (inst->dst.file != VGRF && inst->dst.file != MRF) || inst->predicate || inst->src[0].file != VGRF || inst->dst.type != inst->src[0].type || inst->src[0].abs || inst->src[0].negate || inst->src[0].reladdr) continue; /* Remove no-op MOVs */ if (inst->dst.file == inst->src[0].file && inst->dst.nr == inst->src[0].nr && inst->dst.offset / REG_SIZE == inst->src[0].offset / REG_SIZE) { bool is_nop_mov = true; for (unsigned c = 0; c < 4; c++) { if ((inst->dst.writemask & (1 << c)) == 0) continue; if (BRW_GET_SWZ(inst->src[0].swizzle, c) != c) { is_nop_mov = false; break; } } if (is_nop_mov) { inst->remove(block); progress = true; continue; } } bool to_mrf = (inst->dst.file == MRF); /* Can't coalesce this GRF if someone else was going to * read it later. */ if (var_range_end(var_from_reg(alloc, dst_reg(inst->src[0])), 4) > ip) continue; /* We need to check interference with the final destination between this * instruction and the earliest instruction involved in writing the GRF * we're eliminating. To do that, keep track of which of our source * channels we've seen initialized. */ const unsigned chans_needed = brw_apply_inv_swizzle_to_mask(inst->src[0].swizzle, inst->dst.writemask); unsigned chans_remaining = chans_needed; /* Now walk up the instruction stream trying to see if we can rewrite * everything writing to the temporary to write into the destination * instead. */ vec4_instruction *_scan_inst = (vec4_instruction *)inst->prev; foreach_inst_in_block_reverse_starting_from(vec4_instruction, scan_inst, inst) { _scan_inst = scan_inst; if (inst->src[0].in_range(scan_inst->dst, scan_inst->regs_written)) { /* Found something writing to the reg we want to coalesce away. */ if (to_mrf) { /* SEND instructions can't have MRF as a destination. */ if (scan_inst->mlen) break; if (devinfo->gen == 6) { /* gen6 math instructions must have the destination be * VGRF, so no compute-to-MRF for them. */ if (scan_inst->is_math()) { break; } } } /* This doesn't handle saturation on the instruction we * want to coalesce away if the register types do not match. * But if scan_inst is a non type-converting 'mov', we can fix * the types later. */ if (inst->saturate && inst->dst.type != scan_inst->dst.type && !(scan_inst->opcode == BRW_OPCODE_MOV && scan_inst->dst.type == scan_inst->src[0].type)) break; /* If we can't handle the swizzle, bail. */ if (!scan_inst->can_reswizzle(devinfo, inst->dst.writemask, inst->src[0].swizzle, chans_needed)) { break; } /* This doesn't handle coalescing of multiple registers. */ if (scan_inst->regs_written > 1) break; /* Mark which channels we found unconditional writes for. */ if (!scan_inst->predicate) chans_remaining &= ~scan_inst->dst.writemask; if (chans_remaining == 0) break; } /* You can't read from an MRF, so if someone else reads our MRF's * source GRF that we wanted to rewrite, that stops us. If it's a * GRF we're trying to coalesce to, we don't actually handle * rewriting sources so bail in that case as well. */ bool interfered = false; for (int i = 0; i < 3; i++) { if (inst->src[0].in_range(scan_inst->src[i], scan_inst->regs_read(i))) interfered = true; } if (interfered) break; /* If somebody else writes the same channels of our destination here, * we can't coalesce before that. */ if (inst->dst.in_range(scan_inst->dst, scan_inst->regs_written) && (inst->dst.writemask & scan_inst->dst.writemask) != 0) { break; } /* Check for reads of the register we're trying to coalesce into. We * can't go rewriting instructions above that to put some other value * in the register instead. */ if (to_mrf && scan_inst->mlen > 0) { if (inst->dst.nr >= scan_inst->base_mrf && inst->dst.nr < scan_inst->base_mrf + scan_inst->mlen) { break; } } else { for (int i = 0; i < 3; i++) { if (inst->dst.in_range(scan_inst->src[i], scan_inst->regs_read(i))) interfered = true; } if (interfered) break; } } if (chans_remaining == 0) { /* If we've made it here, we have an MOV we want to coalesce out, and * a scan_inst pointing to the earliest instruction involved in * computing the value. Now go rewrite the instruction stream * between the two. */ vec4_instruction *scan_inst = _scan_inst; while (scan_inst != inst) { if (scan_inst->dst.file == VGRF && scan_inst->dst.nr == inst->src[0].nr && scan_inst->dst.offset / REG_SIZE == inst->src[0].offset / REG_SIZE) { scan_inst->reswizzle(inst->dst.writemask, inst->src[0].swizzle); scan_inst->dst.file = inst->dst.file; scan_inst->dst.nr = inst->dst.nr; scan_inst->dst.offset = scan_inst->dst.offset % REG_SIZE + ROUND_DOWN_TO(inst->dst.offset, REG_SIZE); if (inst->saturate && inst->dst.type != scan_inst->dst.type) { /* If we have reached this point, scan_inst is a non * type-converting 'mov' and we can modify its register types * to match the ones in inst. Otherwise, we could have an * incorrect saturation result. */ scan_inst->dst.type = inst->dst.type; scan_inst->src[0].type = inst->src[0].type; } scan_inst->saturate |= inst->saturate; } scan_inst = (vec4_instruction *)scan_inst->next; } inst->remove(block); progress = true; } } if (progress) invalidate_live_intervals(); return progress; } /** * Eliminate FIND_LIVE_CHANNEL instructions occurring outside any control * flow. We could probably do better here with some form of divergence * analysis. */ bool vec4_visitor::eliminate_find_live_channel() { bool progress = false; unsigned depth = 0; foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) { switch (inst->opcode) { case BRW_OPCODE_IF: case BRW_OPCODE_DO: depth++; break; case BRW_OPCODE_ENDIF: case BRW_OPCODE_WHILE: depth--; break; case SHADER_OPCODE_FIND_LIVE_CHANNEL: if (depth == 0) { inst->opcode = BRW_OPCODE_MOV; inst->src[0] = brw_imm_d(0); inst->force_writemask_all = true; progress = true; } break; default: break; } } return progress; } /** * Splits virtual GRFs requesting more than one contiguous physical register. * * We initially create large virtual GRFs for temporary structures, arrays, * and matrices, so that the dereference visitor functions can add reg_offsets * to work their way down to the actual member being accessed. But when it * comes to optimization, we'd like to treat each register as individual * storage if possible. * * So far, the only thing that might prevent splitting is a send message from * a GRF on IVB. */ void vec4_visitor::split_virtual_grfs() { int num_vars = this->alloc.count; int new_virtual_grf[num_vars]; bool split_grf[num_vars]; memset(new_virtual_grf, 0, sizeof(new_virtual_grf)); /* Try to split anything > 0 sized. */ for (int i = 0; i < num_vars; i++) { split_grf[i] = this->alloc.sizes[i] != 1; } /* Check that the instructions are compatible with the registers we're trying * to split. */ foreach_block_and_inst(block, vec4_instruction, inst, cfg) { if (inst->dst.file == VGRF && inst->regs_written > 1) split_grf[inst->dst.nr] = false; for (int i = 0; i < 3; i++) { if (inst->src[i].file == VGRF && inst->regs_read(i) > 1) split_grf[inst->src[i].nr] = false; } } /* Allocate new space for split regs. Note that the virtual * numbers will be contiguous. */ for (int i = 0; i < num_vars; i++) { if (!split_grf[i]) continue; new_virtual_grf[i] = alloc.allocate(1); for (unsigned j = 2; j < this->alloc.sizes[i]; j++) { unsigned reg = alloc.allocate(1); assert(reg == new_virtual_grf[i] + j - 1); (void) reg; } this->alloc.sizes[i] = 1; } foreach_block_and_inst(block, vec4_instruction, inst, cfg) { if (inst->dst.file == VGRF && split_grf[inst->dst.nr] && inst->dst.offset / REG_SIZE != 0) { inst->dst.nr = (new_virtual_grf[inst->dst.nr] + inst->dst.offset / REG_SIZE - 1); inst->dst.offset %= REG_SIZE; } for (int i = 0; i < 3; i++) { if (inst->src[i].file == VGRF && split_grf[inst->src[i].nr] && inst->src[i].offset / REG_SIZE != 0) { inst->src[i].nr = (new_virtual_grf[inst->src[i].nr] + inst->src[i].offset / REG_SIZE - 1); inst->src[i].offset %= REG_SIZE; } } } invalidate_live_intervals(); } void vec4_visitor::dump_instruction(backend_instruction *be_inst) { dump_instruction(be_inst, stderr); } void vec4_visitor::dump_instruction(backend_instruction *be_inst, FILE *file) { vec4_instruction *inst = (vec4_instruction *)be_inst; if (inst->predicate) { fprintf(file, "(%cf0.%d%s) ", inst->predicate_inverse ? '-' : '+', inst->flag_subreg, pred_ctrl_align16[inst->predicate]); } fprintf(file, "%s", brw_instruction_name(devinfo, inst->opcode)); if (inst->saturate) fprintf(file, ".sat"); if (inst->conditional_mod) { fprintf(file, "%s", conditional_modifier[inst->conditional_mod]); if (!inst->predicate && (devinfo->gen < 5 || (inst->opcode != BRW_OPCODE_SEL && inst->opcode != BRW_OPCODE_IF && inst->opcode != BRW_OPCODE_WHILE))) { fprintf(file, ".f0.%d", inst->flag_subreg); } } fprintf(file, " "); switch (inst->dst.file) { case VGRF: fprintf(file, "vgrf%d.%d", inst->dst.nr, inst->dst.offset / REG_SIZE); break; case FIXED_GRF: fprintf(file, "g%d", inst->dst.nr); break; case MRF: fprintf(file, "m%d", inst->dst.nr); break; case ARF: switch (inst->dst.nr) { case BRW_ARF_NULL: fprintf(file, "null"); break; case BRW_ARF_ADDRESS: fprintf(file, "a0.%d", inst->dst.subnr); break; case BRW_ARF_ACCUMULATOR: fprintf(file, "acc%d", inst->dst.subnr); break; case BRW_ARF_FLAG: fprintf(file, "f%d.%d", inst->dst.nr & 0xf, inst->dst.subnr); break; default: fprintf(file, "arf%d.%d", inst->dst.nr & 0xf, inst->dst.subnr); break; } if (inst->dst.subnr) fprintf(file, "+%d", inst->dst.subnr); break; case BAD_FILE: fprintf(file, "(null)"); break; case IMM: case ATTR: case UNIFORM: unreachable("not reached"); } if (inst->dst.writemask != WRITEMASK_XYZW) { fprintf(file, "."); if (inst->dst.writemask & 1) fprintf(file, "x"); if (inst->dst.writemask & 2) fprintf(file, "y"); if (inst->dst.writemask & 4) fprintf(file, "z"); if (inst->dst.writemask & 8) fprintf(file, "w"); } fprintf(file, ":%s", brw_reg_type_letters(inst->dst.type)); if (inst->src[0].file != BAD_FILE) fprintf(file, ", "); for (int i = 0; i < 3 && inst->src[i].file != BAD_FILE; i++) { if (inst->src[i].negate) fprintf(file, "-"); if (inst->src[i].abs) fprintf(file, "|"); switch (inst->src[i].file) { case VGRF: fprintf(file, "vgrf%d", inst->src[i].nr); break; case FIXED_GRF: fprintf(file, "g%d", inst->src[i].nr); break; case ATTR: fprintf(file, "attr%d", inst->src[i].nr); break; case UNIFORM: fprintf(file, "u%d", inst->src[i].nr); break; case IMM: switch (inst->src[i].type) { case BRW_REGISTER_TYPE_F: fprintf(file, "%fF", inst->src[i].f); break; case BRW_REGISTER_TYPE_D: fprintf(file, "%dD", inst->src[i].d); break; case BRW_REGISTER_TYPE_UD: fprintf(file, "%uU", inst->src[i].ud); break; case BRW_REGISTER_TYPE_VF: fprintf(file, "[%-gF, %-gF, %-gF, %-gF]", brw_vf_to_float((inst->src[i].ud >> 0) & 0xff), brw_vf_to_float((inst->src[i].ud >> 8) & 0xff), brw_vf_to_float((inst->src[i].ud >> 16) & 0xff), brw_vf_to_float((inst->src[i].ud >> 24) & 0xff)); break; default: fprintf(file, "???"); break; } break; case ARF: switch (inst->src[i].nr) { case BRW_ARF_NULL: fprintf(file, "null"); break; case BRW_ARF_ADDRESS: fprintf(file, "a0.%d", inst->src[i].subnr); break; case BRW_ARF_ACCUMULATOR: fprintf(file, "acc%d", inst->src[i].subnr); break; case BRW_ARF_FLAG: fprintf(file, "f%d.%d", inst->src[i].nr & 0xf, inst->src[i].subnr); break; default: fprintf(file, "arf%d.%d", inst->src[i].nr & 0xf, inst->src[i].subnr); break; } if (inst->src[i].subnr) fprintf(file, "+%d", inst->src[i].subnr); break; case BAD_FILE: fprintf(file, "(null)"); break; case MRF: unreachable("not reached"); } /* Don't print .0; and only VGRFs have reg_offsets and sizes */ if (inst->src[i].offset / REG_SIZE != 0 && inst->src[i].file == VGRF && alloc.sizes[inst->src[i].nr] != 1) fprintf(file, ".%d", inst->src[i].offset / REG_SIZE); if (inst->src[i].file != IMM) { static const char *chans[4] = {"x", "y", "z", "w"}; fprintf(file, "."); for (int c = 0; c < 4; c++) { fprintf(file, "%s", chans[BRW_GET_SWZ(inst->src[i].swizzle, c)]); } } if (inst->src[i].abs) fprintf(file, "|"); if (inst->src[i].file != IMM) { fprintf(file, ":%s", brw_reg_type_letters(inst->src[i].type)); } if (i < 2 && inst->src[i + 1].file != BAD_FILE) fprintf(file, ", "); } if (inst->force_writemask_all) fprintf(file, " NoMask"); fprintf(file, "\n"); } static inline struct brw_reg attribute_to_hw_reg(int attr, bool interleaved) { if (interleaved) return stride(brw_vec4_grf(attr / 2, (attr % 2) * 4), 0, 4, 1); else return brw_vec8_grf(attr, 0); } /** * Replace each register of type ATTR in this->instructions with a reference * to a fixed HW register. * * If interleaved is true, then each attribute takes up half a register, with * register N containing attribute 2*N in its first half and attribute 2*N+1 * in its second half (this corresponds to the payload setup used by geometry * shaders in "single" or "dual instanced" dispatch mode). If interleaved is * false, then each attribute takes up a whole register, with register N * containing attribute N (this corresponds to the payload setup used by * vertex shaders, and by geometry shaders in "dual object" dispatch mode). */ void vec4_visitor::lower_attributes_to_hw_regs(const int *attribute_map, bool interleaved) { foreach_block_and_inst(block, vec4_instruction, inst, cfg) { for (int i = 0; i < 3; i++) { if (inst->src[i].file != ATTR) continue; int grf = attribute_map[inst->src[i].nr + inst->src[i].offset / REG_SIZE]; /* All attributes used in the shader need to have been assigned a * hardware register by the caller */ assert(grf != 0); struct brw_reg reg = attribute_to_hw_reg(grf, interleaved); reg.swizzle = inst->src[i].swizzle; reg.type = inst->src[i].type; if (inst->src[i].abs) reg = brw_abs(reg); if (inst->src[i].negate) reg = negate(reg); inst->src[i] = reg; } } } int vec4_vs_visitor::setup_attributes(int payload_reg) { int nr_attributes; int attribute_map[VERT_ATTRIB_MAX + 2]; memset(attribute_map, 0, sizeof(attribute_map)); nr_attributes = 0; for (int i = 0; i < VERT_ATTRIB_MAX; i++) { if (vs_prog_data->inputs_read & BITFIELD64_BIT(i)) { attribute_map[i] = payload_reg + nr_attributes; nr_attributes++; } } /* VertexID is stored by the VF as the last vertex element, but we * don't represent it with a flag in inputs_read, so we call it * VERT_ATTRIB_MAX. */ if (vs_prog_data->uses_vertexid || vs_prog_data->uses_instanceid || vs_prog_data->uses_basevertex || vs_prog_data->uses_baseinstance) { attribute_map[VERT_ATTRIB_MAX] = payload_reg + nr_attributes; nr_attributes++; } if (vs_prog_data->uses_drawid) { attribute_map[VERT_ATTRIB_MAX + 1] = payload_reg + nr_attributes; nr_attributes++; } lower_attributes_to_hw_regs(attribute_map, false /* interleaved */); return payload_reg + vs_prog_data->nr_attributes; } int vec4_visitor::setup_uniforms(int reg) { prog_data->base.dispatch_grf_start_reg = reg; /* The pre-gen6 VS requires that some push constants get loaded no * matter what, or the GPU would hang. */ if (devinfo->gen < 6 && this->uniforms == 0) { stage_prog_data->param = reralloc(NULL, stage_prog_data->param, const gl_constant_value *, 4); for (unsigned int i = 0; i < 4; i++) { unsigned int slot = this->uniforms * 4 + i; static gl_constant_value zero = { 0.0 }; stage_prog_data->param[slot] = &zero; } this->uniforms++; reg++; } else { reg += ALIGN(uniforms, 2) / 2; } stage_prog_data->nr_params = this->uniforms * 4; prog_data->base.curb_read_length = reg - prog_data->base.dispatch_grf_start_reg; return reg; } void vec4_vs_visitor::setup_payload(void) { int reg = 0; /* The payload always contains important data in g0, which contains * the URB handles that are passed on to the URB write at the end * of the thread. So, we always start push constants at g1. */ reg++; reg = setup_uniforms(reg); reg = setup_attributes(reg); this->first_non_payload_grf = reg; } bool vec4_visitor::lower_minmax() { assert(devinfo->gen < 6); bool progress = false; foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) { const vec4_builder ibld(this, block, inst); if (inst->opcode == BRW_OPCODE_SEL && inst->predicate == BRW_PREDICATE_NONE) { /* FIXME: Using CMP doesn't preserve the NaN propagation semantics of * the original SEL.L/GE instruction */ ibld.CMP(ibld.null_reg_d(), inst->src[0], inst->src[1], inst->conditional_mod); inst->predicate = BRW_PREDICATE_NORMAL; inst->conditional_mod = BRW_CONDITIONAL_NONE; progress = true; } } if (progress) invalidate_live_intervals(); return progress; } src_reg vec4_visitor::get_timestamp() { assert(devinfo->gen >= 7); src_reg ts = src_reg(brw_reg(BRW_ARCHITECTURE_REGISTER_FILE, BRW_ARF_TIMESTAMP, 0, 0, 0, BRW_REGISTER_TYPE_UD, BRW_VERTICAL_STRIDE_0, BRW_WIDTH_4, BRW_HORIZONTAL_STRIDE_4, BRW_SWIZZLE_XYZW, WRITEMASK_XYZW)); dst_reg dst = dst_reg(this, glsl_type::uvec4_type); vec4_instruction *mov = emit(MOV(dst, ts)); /* We want to read the 3 fields we care about (mostly field 0, but also 2) * even if it's not enabled in the dispatch. */ mov->force_writemask_all = true; return src_reg(dst); } void vec4_visitor::emit_shader_time_begin() { current_annotation = "shader time start"; shader_start_time = get_timestamp(); } void vec4_visitor::emit_shader_time_end() { current_annotation = "shader time end"; src_reg shader_end_time = get_timestamp(); /* Check that there weren't any timestamp reset events (assuming these * were the only two timestamp reads that happened). */ src_reg reset_end = shader_end_time; reset_end.swizzle = BRW_SWIZZLE_ZZZZ; vec4_instruction *test = emit(AND(dst_null_ud(), reset_end, brw_imm_ud(1u))); test->conditional_mod = BRW_CONDITIONAL_Z; emit(IF(BRW_PREDICATE_NORMAL)); /* Take the current timestamp and get the delta. */ shader_start_time.negate = true; dst_reg diff = dst_reg(this, glsl_type::uint_type); emit(ADD(diff, shader_start_time, shader_end_time)); /* If there were no instructions between the two timestamp gets, the diff * is 2 cycles. Remove that overhead, so I can forget about that when * trying to determine the time taken for single instructions. */ emit(ADD(diff, src_reg(diff), brw_imm_ud(-2u))); emit_shader_time_write(0, src_reg(diff)); emit_shader_time_write(1, brw_imm_ud(1u)); emit(BRW_OPCODE_ELSE); emit_shader_time_write(2, brw_imm_ud(1u)); emit(BRW_OPCODE_ENDIF); } void vec4_visitor::emit_shader_time_write(int shader_time_subindex, src_reg value) { dst_reg dst = dst_reg(this, glsl_type::get_array_instance(glsl_type::vec4_type, 2)); dst_reg offset = dst; dst_reg time = dst; time.offset += REG_SIZE; offset.type = BRW_REGISTER_TYPE_UD; int index = shader_time_index * 3 + shader_time_subindex; emit(MOV(offset, brw_imm_d(index * SHADER_TIME_STRIDE))); time.type = BRW_REGISTER_TYPE_UD; emit(MOV(time, value)); vec4_instruction *inst = emit(SHADER_OPCODE_SHADER_TIME_ADD, dst_reg(), src_reg(dst)); inst->mlen = 2; } void vec4_visitor::convert_to_hw_regs() { foreach_block_and_inst(block, vec4_instruction, inst, cfg) { for (int i = 0; i < 3; i++) { struct src_reg &src = inst->src[i]; struct brw_reg reg; switch (src.file) { case VGRF: reg = brw_vec8_grf(src.nr + src.offset / REG_SIZE, 0); reg.type = src.type; reg.swizzle = src.swizzle; reg.abs = src.abs; reg.negate = src.negate; break; case UNIFORM: reg = stride(brw_vec4_grf(prog_data->base.dispatch_grf_start_reg + (src.nr + src.offset / 16) / 2, ((src.nr + src.offset / 16) % 2) * 4), 0, 4, 1); reg.type = src.type; reg.swizzle = src.swizzle; reg.abs = src.abs; reg.negate = src.negate; /* This should have been moved to pull constants. */ assert(!src.reladdr); break; case ARF: case FIXED_GRF: case IMM: continue; case BAD_FILE: /* Probably unused. */ reg = brw_null_reg(); break; case MRF: case ATTR: unreachable("not reached"); } src = reg; } if (inst->is_3src(devinfo)) { /* 3-src instructions with scalar sources support arbitrary subnr, * but don't actually use swizzles. Convert swizzle into subnr. */ for (int i = 0; i < 3; i++) { if (inst->src[i].vstride == BRW_VERTICAL_STRIDE_0) { assert(brw_is_single_value_swizzle(inst->src[i].swizzle)); inst->src[i].subnr += 4 * BRW_GET_SWZ(inst->src[i].swizzle, 0); } } } dst_reg &dst = inst->dst; struct brw_reg reg; switch (inst->dst.file) { case VGRF: reg = brw_vec8_grf(dst.nr + dst.offset / REG_SIZE, 0); reg.type = dst.type; reg.writemask = dst.writemask; break; case MRF: assert(((dst.nr + dst.offset / REG_SIZE) & ~BRW_MRF_COMPR4) < BRW_MAX_MRF(devinfo->gen)); reg = brw_message_reg(dst.nr + dst.offset / REG_SIZE); reg.type = dst.type; reg.writemask = dst.writemask; break; case ARF: case FIXED_GRF: reg = dst.as_brw_reg(); break; case BAD_FILE: reg = brw_null_reg(); break; case IMM: case ATTR: case UNIFORM: unreachable("not reached"); } dst = reg; } } bool vec4_visitor::run() { if (shader_time_index >= 0) emit_shader_time_begin(); emit_prolog(); emit_nir_code(); if (failed) return false; base_ir = NULL; emit_thread_end(); calculate_cfg(); /* Before any optimization, push array accesses out to scratch * space where we need them to be. This pass may allocate new * virtual GRFs, so we want to do it early. It also makes sure * that we have reladdr computations available for CSE, since we'll * often do repeated subexpressions for those. */ move_grf_array_access_to_scratch(); move_uniform_array_access_to_pull_constants(); pack_uniform_registers(); move_push_constants_to_pull_constants(); split_virtual_grfs(); #define OPT(pass, args...) ({ \ pass_num++; \ bool this_progress = pass(args); \ \ if (unlikely(INTEL_DEBUG & DEBUG_OPTIMIZER) && this_progress) { \ char filename[64]; \ snprintf(filename, 64, "%s-%s-%02d-%02d-" #pass, \ stage_abbrev, nir->info.name, iteration, pass_num); \ \ backend_shader::dump_instructions(filename); \ } \ \ progress = progress || this_progress; \ this_progress; \ }) if (unlikely(INTEL_DEBUG & DEBUG_OPTIMIZER)) { char filename[64]; snprintf(filename, 64, "%s-%s-00-00-start", stage_abbrev, nir->info.name); backend_shader::dump_instructions(filename); } bool progress; int iteration = 0; int pass_num = 0; do { progress = false; pass_num = 0; iteration++; OPT(opt_predicated_break, this); OPT(opt_reduce_swizzle); OPT(dead_code_eliminate); OPT(dead_control_flow_eliminate, this); OPT(opt_copy_propagation); OPT(opt_cmod_propagation); OPT(opt_cse); OPT(opt_algebraic); OPT(opt_register_coalesce); OPT(eliminate_find_live_channel); } while (progress); pass_num = 0; if (OPT(opt_vector_float)) { OPT(opt_cse); OPT(opt_copy_propagation, false); OPT(opt_copy_propagation, true); OPT(dead_code_eliminate); } if (devinfo->gen <= 5 && OPT(lower_minmax)) { OPT(opt_cmod_propagation); OPT(opt_cse); OPT(opt_copy_propagation); OPT(dead_code_eliminate); } if (failed) return false; setup_payload(); if (unlikely(INTEL_DEBUG & DEBUG_SPILL_VEC4)) { /* Debug of register spilling: Go spill everything. */ const int grf_count = alloc.count; float spill_costs[alloc.count]; bool no_spill[alloc.count]; evaluate_spill_costs(spill_costs, no_spill); for (int i = 0; i < grf_count; i++) { if (no_spill[i]) continue; spill_reg(i); } } bool allocated_without_spills = reg_allocate(); if (!allocated_without_spills) { compiler->shader_perf_log(log_data, "%s shader triggered register spilling. " "Try reducing the number of live vec4 values " "to improve performance.\n", stage_name); while (!reg_allocate()) { if (failed) return false; } } opt_schedule_instructions(); opt_set_dependency_control(); convert_to_hw_regs(); if (last_scratch > 0) { prog_data->base.total_scratch = brw_get_scratch_size(last_scratch * REG_SIZE); } return !failed; } } /* namespace brw */ extern "C" { /** * Compile a vertex shader. * * Returns the final assembly and the program's size. */ const unsigned * brw_compile_vs(const struct brw_compiler *compiler, void *log_data, void *mem_ctx, const struct brw_vs_prog_key *key, struct brw_vs_prog_data *prog_data, const nir_shader *src_shader, gl_clip_plane *clip_planes, bool use_legacy_snorm_formula, int shader_time_index, unsigned *final_assembly_size, char **error_str) { const bool is_scalar = compiler->scalar_stage[MESA_SHADER_VERTEX]; nir_shader *shader = nir_shader_clone(mem_ctx, src_shader); shader = brw_nir_apply_sampler_key(shader, compiler->devinfo, &key->tex, is_scalar); brw_nir_lower_vs_inputs(shader, compiler->devinfo, is_scalar, use_legacy_snorm_formula, key->gl_attrib_wa_flags); brw_nir_lower_vue_outputs(shader, is_scalar); shader = brw_postprocess_nir(shader, compiler->devinfo, is_scalar); const unsigned *assembly = NULL; unsigned nr_attributes = _mesa_bitcount_64(prog_data->inputs_read); /* gl_VertexID and gl_InstanceID are system values, but arrive via an * incoming vertex attribute. So, add an extra slot. */ if (shader->info.system_values_read & (BITFIELD64_BIT(SYSTEM_VALUE_BASE_VERTEX) | BITFIELD64_BIT(SYSTEM_VALUE_BASE_INSTANCE) | BITFIELD64_BIT(SYSTEM_VALUE_VERTEX_ID_ZERO_BASE) | BITFIELD64_BIT(SYSTEM_VALUE_INSTANCE_ID))) { nr_attributes++; } /* gl_DrawID has its very own vec4 */ if (shader->info.system_values_read & BITFIELD64_BIT(SYSTEM_VALUE_DRAW_ID)) { nr_attributes++; } unsigned nr_attribute_slots = nr_attributes + _mesa_bitcount_64(shader->info.double_inputs_read); /* The 3DSTATE_VS documentation lists the lower bound on "Vertex URB Entry * Read Length" as 1 in vec4 mode, and 0 in SIMD8 mode. Empirically, in * vec4 mode, the hardware appears to wedge unless we read something. */ if (is_scalar) prog_data->base.urb_read_length = DIV_ROUND_UP(nr_attribute_slots, 2); else prog_data->base.urb_read_length = DIV_ROUND_UP(MAX2(nr_attribute_slots, 1), 2); prog_data->nr_attributes = nr_attributes; prog_data->nr_attribute_slots = nr_attribute_slots; /* Since vertex shaders reuse the same VUE entry for inputs and outputs * (overwriting the original contents), we need to make sure the size is * the larger of the two. */ const unsigned vue_entries = MAX2(nr_attribute_slots, (unsigned)prog_data->base.vue_map.num_slots); if (compiler->devinfo->gen == 6) prog_data->base.urb_entry_size = DIV_ROUND_UP(vue_entries, 8); else prog_data->base.urb_entry_size = DIV_ROUND_UP(vue_entries, 4); if (is_scalar) { prog_data->base.dispatch_mode = DISPATCH_MODE_SIMD8; fs_visitor v(compiler, log_data, mem_ctx, key, &prog_data->base.base, NULL, /* prog; Only used for TEXTURE_RECTANGLE on gen < 8 */ shader, 8, shader_time_index); if (!v.run_vs(clip_planes)) { if (error_str) *error_str = ralloc_strdup(mem_ctx, v.fail_msg); return NULL; } prog_data->base.base.dispatch_grf_start_reg = v.payload.num_regs; fs_generator g(compiler, log_data, mem_ctx, (void *) key, &prog_data->base.base, v.promoted_constants, v.runtime_check_aads_emit, MESA_SHADER_VERTEX); if (INTEL_DEBUG & DEBUG_VS) { const char *debug_name = ralloc_asprintf(mem_ctx, "%s vertex shader %s", shader->info.label ? shader->info.label : "unnamed", shader->info.name); g.enable_debug(debug_name); } g.generate_code(v.cfg, 8); assembly = g.get_assembly(final_assembly_size); } if (!assembly) { prog_data->base.dispatch_mode = DISPATCH_MODE_4X2_DUAL_OBJECT; vec4_vs_visitor v(compiler, log_data, key, prog_data, shader, clip_planes, mem_ctx, shader_time_index, use_legacy_snorm_formula); if (!v.run()) { if (error_str) *error_str = ralloc_strdup(mem_ctx, v.fail_msg); return NULL; } assembly = brw_vec4_generate_assembly(compiler, log_data, mem_ctx, shader, &prog_data->base, v.cfg, final_assembly_size); } return assembly; } } /* extern "C" */