From: Kenneth Graunke Date: Wed, 14 Nov 2012 04:33:33 +0000 (-0800) Subject: i965: Remove some dead code optimization passes. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c4b99c1857211a8bb2a95b81cc5ae7517f0293dc;p=mesa.git i965: Remove some dead code optimization passes. The old brw_remove_grf_to_mrf_moves() pass is obsolete and replaced by fs_visitor::compute_to_mrf(). The old brw_remove_duplicate_mrf_moves() pass is obsolete and replaced by fs_visitor::remove_duplicate_mrf_writes(). The remaining pass, brw_set_dp4_dependency_control(), is currently unused, but could be, so I'm leaving it for now. Reviewed-by: Eric Anholt --- diff --git a/src/mesa/drivers/dri/i965/brw_optimize.c b/src/mesa/drivers/dri/i965/brw_optimize.c index 1e3f4d9cd4b..bb6e83711a8 100644 --- a/src/mesa/drivers/dri/i965/brw_optimize.c +++ b/src/mesa/drivers/dri/i965/brw_optimize.c @@ -86,550 +86,6 @@ const struct brw_instruction_info brw_opcodes[128] = { [BRW_OPCODE_ENDIF] = { .name = "endif", .nsrc = 2, .ndst = 0 }, }; -static INLINE -bool brw_is_arithmetic_inst(const struct brw_instruction *inst) -{ - return brw_opcodes[inst->header.opcode].is_arith; -} - -static const GLuint inst_stride[7] = { - [0] = 0, - [1] = 1, - [2] = 2, - [3] = 4, - [4] = 8, - [5] = 16, - [6] = 32 -}; - -static const GLuint inst_type_size[8] = { - [BRW_REGISTER_TYPE_UD] = 4, - [BRW_REGISTER_TYPE_D] = 4, - [BRW_REGISTER_TYPE_UW] = 2, - [BRW_REGISTER_TYPE_W] = 2, - [BRW_REGISTER_TYPE_UB] = 1, - [BRW_REGISTER_TYPE_B] = 1, - [BRW_REGISTER_TYPE_F] = 4 -}; - -static INLINE bool -brw_is_grf_written(const struct brw_instruction *inst, - int reg_index, int size, - int gen) -{ - if (brw_opcodes[inst->header.opcode].ndst == 0) - return false; - - if (inst->bits1.da1.dest_address_mode != BRW_ADDRESS_DIRECT) - if (inst->bits1.ia1.dest_reg_file == BRW_GENERAL_REGISTER_FILE) - return true; - - if (inst->bits1.da1.dest_reg_file != BRW_GENERAL_REGISTER_FILE) - return false; - - const int reg_start = reg_index * REG_SIZE; - const int reg_end = reg_start + size; - - const int type_size = inst_type_size[inst->bits1.da1.dest_reg_type]; - const int write_start = inst->bits1.da1.dest_reg_nr*REG_SIZE - + inst->bits1.da1.dest_subreg_nr; - int length, write_end; - - /* SEND is specific */ - if (inst->header.opcode == BRW_OPCODE_SEND) { - if (gen >= 5) - length = inst->bits3.generic_gen5.response_length*REG_SIZE; - else - length = inst->bits3.generic.response_length*REG_SIZE; - } - else { - length = 1 << inst->header.execution_size; - length *= type_size; - length *= inst->bits1.da1.dest_horiz_stride; - } - - /* If the two intervals intersect, we overwrite the register */ - write_end = write_start + length; - const int left = MAX2(write_start, reg_start); - const int right = MIN2(write_end, reg_end); - - return left < right; -} - -static bool -brw_is_mrf_written_alu(const struct brw_instruction *inst, - int reg_index, int size) -{ - if (brw_opcodes[inst->header.opcode].ndst == 0) - return false; - - if (inst->bits1.da1.dest_reg_file != BRW_MESSAGE_REGISTER_FILE) - return false; - - if (inst->bits1.da1.dest_address_mode != BRW_ADDRESS_DIRECT) - return true; - - const int reg_start = reg_index * REG_SIZE; - const int reg_end = reg_start + size; - - const int mrf_index = inst->bits1.da1.dest_reg_nr & 0x0f; - const int is_compr4 = inst->bits1.da1.dest_reg_nr & BRW_MRF_COMPR4; - const int type_size = inst_type_size[inst->bits1.da1.dest_reg_type]; - - /* We use compr4 with a size != 16 elements. Strange, we conservatively - * consider that we are writing the register. - */ - if (is_compr4 && inst->header.execution_size != BRW_EXECUTE_16) - return true; - - /* Here we write mrf_{i} and mrf_{i+4}. So we read two times 8 elements */ - if (is_compr4) { - const int length = 8 * type_size * inst->bits1.da1.dest_horiz_stride; - - /* First 8-way register */ - const int write_start0 = mrf_index*REG_SIZE - + inst->bits1.da1.dest_subreg_nr; - const int write_end0 = write_start0 + length; - - /* Second 8-way register */ - const int write_start1 = (mrf_index+4)*REG_SIZE - + inst->bits1.da1.dest_subreg_nr; - const int write_end1 = write_start1 + length; - - /* If the two intervals intersect, we overwrite the register */ - const int left0 = MAX2(write_start0, reg_start); - const int right0 = MIN2(write_end0, reg_end); - const int left1 = MAX2(write_start1, reg_start); - const int right1 = MIN2(write_end1, reg_end); - - if (left0 < right0 || left1 < right1) - return true; - } - else { - int length; - length = 1 << inst->header.execution_size; - length *= type_size; - length *= inst->bits1.da1.dest_horiz_stride; - - /* If the two intervals intersect, we write into the register */ - const int write_start = inst->bits1.da1.dest_reg_nr*REG_SIZE - + inst->bits1.da1.dest_subreg_nr; - const int write_end = write_start + length; - const int left = MAX2(write_start, reg_start); - const int right = MIN2(write_end, reg_end); - - if (left < right) - return true; - } - - return false; -} - -/* SEND may perform an implicit mov to a mrf register */ -static bool -brw_is_mrf_written_send(const struct brw_instruction *inst, - int reg_index, int size) -{ - - const int reg_start = reg_index * REG_SIZE; - const int reg_end = reg_start + size; - const int mrf_start = inst->header.destreg__conditionalmod; - const int write_start = mrf_start * REG_SIZE; - const int write_end = write_start + REG_SIZE; - const int left = MAX2(write_start, reg_start); - const int right = MIN2(write_end, reg_end); - - if (inst->header.opcode != BRW_OPCODE_SEND || - inst->bits1.da1.src0_reg_file == 0) - return false; - - return left < right; -} - -/* Specific path for message register since we need to handle the compr4 case */ -static INLINE bool -brw_is_mrf_written(const struct brw_instruction *inst, int reg_index, int size) -{ - return (brw_is_mrf_written_alu(inst, reg_index, size) || - brw_is_mrf_written_send(inst, reg_index, size)); -} - -static INLINE bool -brw_is_mrf_read(const struct brw_instruction *inst, - int reg_index, int size, int gen) -{ - if (inst->header.opcode != BRW_OPCODE_SEND) - return false; - if (inst->bits2.da1.src0_address_mode != BRW_ADDRESS_DIRECT) - return true; - - const int reg_start = reg_index*REG_SIZE; - const int reg_end = reg_start + size; - - int length, read_start, read_end; - if (gen >= 5) - length = inst->bits3.generic_gen5.msg_length*REG_SIZE; - else - length = inst->bits3.generic.msg_length*REG_SIZE; - - /* Look if SEND uses an implicit mov. In that case, we read one less register - * (but we write it) - */ - if (inst->bits1.da1.src0_reg_file != 0) - read_start = inst->header.destreg__conditionalmod; - else { - length--; - read_start = inst->header.destreg__conditionalmod + 1; - } - read_start *= REG_SIZE; - read_end = read_start + length; - - const int left = MAX2(read_start, reg_start); - const int right = MIN2(read_end, reg_end); - - return left < right; -} - -static INLINE bool -brw_is_grf_read(const struct brw_instruction *inst, int reg_index, int size) -{ - int i, j; - if (brw_opcodes[inst->header.opcode].nsrc == 0) - return false; - - /* Look at first source. We must take into account register regions to - * monitor carefully the read. Note that we are a bit too conservative here - * since we do not take into account the fact that some complete registers - * may be skipped - */ - if (brw_opcodes[inst->header.opcode].nsrc >= 1) { - - if (inst->bits2.da1.src0_address_mode != BRW_ADDRESS_DIRECT) - if (inst->bits1.ia1.src0_reg_file == BRW_GENERAL_REGISTER_FILE) - return true; - if (inst->bits1.da1.src0_reg_file != BRW_GENERAL_REGISTER_FILE) - return false; - - const int reg_start = reg_index*REG_SIZE; - const int reg_end = reg_start + size; - - /* See if at least one of this element intersects the interval */ - const int type_size = inst_type_size[inst->bits1.da1.src0_reg_type]; - const int elem_num = 1 << inst->header.execution_size; - const int width = 1 << inst->bits2.da1.src0_width; - const int row_num = elem_num >> inst->bits2.da1.src0_width; - const int hs = type_size*inst_stride[inst->bits2.da1.src0_horiz_stride]; - const int vs = type_size*inst_stride[inst->bits2.da1.src0_vert_stride]; - int row_start = inst->bits2.da1.src0_reg_nr*REG_SIZE - + inst->bits2.da1.src0_subreg_nr; - for (j = 0; j < row_num; ++j) { - int write_start = row_start; - for (i = 0; i < width; ++i) { - const int write_end = write_start + type_size; - const int left = write_start > reg_start ? write_start : reg_start; - const int right = write_end < reg_end ? write_end : reg_end; - if (left < right) - return true; - write_start += hs; - } - row_start += vs; - } - } - - /* Second src register */ - if (brw_opcodes[inst->header.opcode].nsrc >= 2) { - - if (inst->bits3.da1.src1_address_mode != BRW_ADDRESS_DIRECT) - if (inst->bits1.ia1.src1_reg_file == BRW_GENERAL_REGISTER_FILE) - return true; - if (inst->bits1.da1.src1_reg_file != BRW_GENERAL_REGISTER_FILE) - return false; - - const int reg_start = reg_index*REG_SIZE; - const int reg_end = reg_start + size; - - /* See if at least one of this element intersects the interval */ - const int type_size = inst_type_size[inst->bits1.da1.src1_reg_type]; - const int elem_num = 1 << inst->header.execution_size; - const int width = 1 << inst->bits3.da1.src1_width; - const int row_num = elem_num >> inst->bits3.da1.src1_width; - const int hs = type_size*inst_stride[inst->bits3.da1.src1_horiz_stride]; - const int vs = type_size*inst_stride[inst->bits3.da1.src1_vert_stride]; - int row_start = inst->bits3.da1.src1_reg_nr*REG_SIZE - + inst->bits3.da1.src1_subreg_nr; - for (j = 0; j < row_num; ++j) { - int write_start = row_start; - for (i = 0; i < width; ++i) { - const int write_end = write_start + type_size; - const int left = write_start > reg_start ? write_start : reg_start; - const int right = write_end < reg_end ? write_end : reg_end; - if (left < right) - return true; - write_start += hs; - } - row_start += vs; - } - } - - return false; -} - -static INLINE bool -brw_is_control_done(const struct brw_instruction *mov) { - return - mov->header.dependency_control != 0 || - mov->header.thread_control != 0 || - mov->header.mask_control != 0 || - mov->header.saturate != 0 || - mov->header.debug_control != 0; -} - -static INLINE bool -brw_is_predicated(const struct brw_instruction *mov) { - return mov->header.predicate_control != 0; -} - -static INLINE bool -brw_is_grf_to_mrf_mov(const struct brw_instruction *mov, - int *mrf_index, - int *grf_index, - bool *is_compr4) -{ - if (brw_is_predicated(mov) || - brw_is_control_done(mov) || - mov->header.debug_control != 0) - return false; - - if (mov->bits1.da1.dest_address_mode != BRW_ADDRESS_DIRECT || - mov->bits1.da1.dest_reg_file != BRW_MESSAGE_REGISTER_FILE || - mov->bits1.da1.dest_reg_type != BRW_REGISTER_TYPE_F || - mov->bits1.da1.dest_horiz_stride != BRW_HORIZONTAL_STRIDE_1 || - mov->bits1.da1.dest_subreg_nr != 0) - return false; - - if (mov->bits2.da1.src0_address_mode != BRW_ADDRESS_DIRECT || - mov->bits1.da1.src0_reg_file != BRW_GENERAL_REGISTER_FILE || - mov->bits1.da1.src0_reg_type != BRW_REGISTER_TYPE_F || - mov->bits2.da1.src0_width != BRW_WIDTH_8 || - mov->bits2.da1.src0_horiz_stride != BRW_HORIZONTAL_STRIDE_1 || - mov->bits2.da1.src0_vert_stride != BRW_VERTICAL_STRIDE_8 || - mov->bits2.da1.src0_subreg_nr != 0 || - mov->bits2.da1.src0_abs != 0 || - mov->bits2.da1.src0_negate != 0) - return false; - - *grf_index = mov->bits2.da1.src0_reg_nr; - *mrf_index = mov->bits1.da1.dest_reg_nr & 0x0f; - *is_compr4 = (mov->bits1.da1.dest_reg_nr & BRW_MRF_COMPR4) != 0; - return true; -} - -static INLINE bool -brw_is_grf_straight_write(const struct brw_instruction *inst, int grf_index) -{ - /* remark: no problem to predicate a SEL instruction */ - if ((!brw_is_predicated(inst) || inst->header.opcode == BRW_OPCODE_SEL) && - brw_is_control_done(inst) == false && - inst->header.execution_size == 4 && - inst->header.access_mode == BRW_ALIGN_1 && - inst->bits1.da1.dest_address_mode == BRW_ADDRESS_DIRECT && - inst->bits1.da1.dest_reg_file == BRW_GENERAL_REGISTER_FILE && - inst->bits1.da1.dest_reg_type == BRW_REGISTER_TYPE_F && - inst->bits1.da1.dest_horiz_stride == BRW_HORIZONTAL_STRIDE_1 && - inst->bits1.da1.dest_reg_nr == grf_index && - inst->bits1.da1.dest_subreg_nr == 0 && - brw_is_arithmetic_inst(inst)) - return true; - - return false; -} - -static INLINE bool -brw_inst_are_equal(const struct brw_instruction *src0, - const struct brw_instruction *src1) -{ - const GLuint *field0 = (GLuint *) src0; - const GLuint *field1 = (GLuint *) src1; - return field0[0] == field1[0] && - field0[1] == field1[1] && - field0[2] == field1[2] && - field0[3] == field1[3]; -} - -static INLINE void -brw_inst_copy(struct brw_instruction *dst, - const struct brw_instruction *src) -{ - GLuint *field_dst = (GLuint *) dst; - const GLuint *field_src = (GLuint *) src; - field_dst[0] = field_src[0]; - field_dst[1] = field_src[1]; - field_dst[2] = field_src[2]; - field_dst[3] = field_src[3]; -} - -static void brw_remove_inst(struct brw_compile *p, const bool *removeInst) -{ - int i, nr_insn = 0, to = 0, from = 0; - - for (from = 0; from < p->nr_insn; ++from) { - if (removeInst[from]) - continue; - if(to != from) - brw_inst_copy(p->store + to, p->store + from); - to++; - } - - for (i = 0; i < p->nr_insn; ++i) - if (removeInst[i] == false) - nr_insn++; - p->nr_insn = nr_insn; -} - -/* The gen code emitter generates a lot of duplications in the - * grf-to-mrf moves, for example when texture sampling with the same - * coordinates from multiple textures.. Here, we monitor same mov - * grf-to-mrf instrutions and remove repeated ones where the operands - * and dst ahven't changed in between. - */ -void brw_remove_duplicate_mrf_moves(struct brw_compile *p) -{ - const int gen = p->brw->intel.gen; - int i, j; - - bool *removeInst = calloc(sizeof(bool), p->nr_insn); - for (i = 0; i < p->nr_insn; i++) { - if (removeInst[i]) - continue; - - const struct brw_instruction *mov = p->store + i; - int mrf_index, grf_index; - bool is_compr4; - - /* Only consider _straight_ grf-to-mrf moves */ - if (!brw_is_grf_to_mrf_mov(mov, &mrf_index, &grf_index, &is_compr4)) - continue; - - const int mrf_index0 = mrf_index; - const int mrf_index1 = is_compr4 ? mrf_index0+4 : mrf_index0+1; - const int simd16_size = 2 * REG_SIZE; - - for (j = i + 1; j < p->nr_insn; j++) { - const struct brw_instruction *inst = p->store + j; - - if (brw_inst_are_equal(mov, inst)) { - removeInst[j] = true; - continue; - } - - if (brw_is_grf_written(inst, grf_index, simd16_size, gen) || - brw_is_mrf_written(inst, mrf_index0, REG_SIZE) || - brw_is_mrf_written(inst, mrf_index1, REG_SIZE)) - break; - } - } - - brw_remove_inst(p, removeInst); - free(removeInst); -} - -/* Replace moves to MRFs where the value moved is the result of a - * normal arithmetic operation with computation right into the MRF. - */ -void brw_remove_grf_to_mrf_moves(struct brw_compile *p) -{ - int i, j, prev; - struct brw_context *brw = p->brw; - const int gen = brw->intel.gen; - const int simd16_size = 2*REG_SIZE; - - bool *removeInst = calloc(sizeof(bool), p->nr_insn); - assert(removeInst); - - for (i = 0; i < p->nr_insn; i++) { - if (removeInst[i]) - continue; - - struct brw_instruction *grf_inst = NULL; - const struct brw_instruction *mov = p->store + i; - int mrf_index, grf_index; - bool is_compr4; - - /* Only consider _straight_ grf-to-mrf moves */ - if (!brw_is_grf_to_mrf_mov(mov, &mrf_index, &grf_index, &is_compr4)) - continue; - - /* Using comp4 enables a stride of 4 for this instruction */ - const int mrf_index0 = mrf_index; - const int mrf_index1 = is_compr4 ? mrf_index+4 : mrf_index+1; - - /* Look where the register has been set */ - prev = i; - bool potential_remove = false; - while (prev--) { - - /* If _one_ instruction writes the grf, we try to remove the mov */ - struct brw_instruction *inst = p->store + prev; - if (brw_is_grf_straight_write(inst, grf_index)) { - potential_remove = true; - grf_inst = inst; - break; - } - - } - - if (potential_remove == false) - continue; - removeInst[i] = true; - - /* Monitor first the section of code between the grf computation and the - * mov. Here we cannot read or write both mrf and grf register - */ - for (j = prev + 1; j < i; ++j) { - struct brw_instruction *inst = p->store + j; - if (removeInst[j]) - continue; - if (brw_is_grf_written(inst, grf_index, simd16_size, gen) || - brw_is_grf_read(inst, grf_index, simd16_size) || - brw_is_mrf_written(inst, mrf_index0, REG_SIZE) || - brw_is_mrf_written(inst, mrf_index1, REG_SIZE) || - brw_is_mrf_read(inst, mrf_index0, REG_SIZE, gen) || - brw_is_mrf_read(inst, mrf_index1, REG_SIZE, gen)) { - removeInst[i] = false; - break; - } - } - - /* After the mov, we can read or write the mrf. If the grf is overwritten, - * we are done - */ - for (j = i + 1; j < p->nr_insn; ++j) { - struct brw_instruction *inst = p->store + j; - if (removeInst[j]) - continue; - - if (brw_is_grf_read(inst, grf_index, simd16_size)) { - removeInst[i] = false; - break; - } - - if (brw_is_grf_straight_write(inst, grf_index)) - break; - } - - /* Note that with the top down traversal, we can safely pacth the mov - * instruction - */ - if (removeInst[i]) { - grf_inst->bits1.da1.dest_reg_file = mov->bits1.da1.dest_reg_file; - grf_inst->bits1.da1.dest_reg_nr = mov->bits1.da1.dest_reg_nr; - } - } - - brw_remove_inst(p, removeInst); - free(removeInst); -} - static bool is_single_channel_dp4(struct brw_instruction *insn) {