1 /* -*- mode: C; c-file-style: "k&r"; tab-width 4; indent-tabs-mode: t; -*- */ 2 3 /* 4 * Copyright (C) 2014 Rob Clark <robclark (at) freedesktop.org> 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 * SOFTWARE. 24 * 25 * Authors: 26 * Rob Clark <robclark (at) freedesktop.org> 27 */ 28 29 #include "util/u_math.h" 30 31 #include "ir3.h" 32 33 /* 34 * Instruction Depth: 35 * 36 * Calculates weighted instruction depth, ie. the sum of # of needed 37 * instructions plus delay slots back to original input (ie INPUT or 38 * CONST). That is to say, an instructions depth is: 39 * 40 * depth(instr) { 41 * d = 0; 42 * // for each src register: 43 * foreach (src in instr->regs[1..n]) 44 * d = max(d, delayslots(src->instr, n) + depth(src->instr)); 45 * return d + 1; 46 * } 47 * 48 * After an instruction's depth is calculated, it is inserted into the 49 * blocks depth sorted list, which is used by the scheduling pass. 50 */ 51 52 /* calculate required # of delay slots between the instruction that 53 * assigns a value and the one that consumes 54 */ 55 int ir3_delayslots(struct ir3_instruction *assigner, 56 struct ir3_instruction *consumer, unsigned n) 57 { 58 /* worst case is cat1-3 (alu) -> cat4/5 needing 6 cycles, normal 59 * alu -> alu needs 3 cycles, cat4 -> alu and texture fetch 60 * handled with sync bits 61 */ 62 63 if (is_meta(assigner)) 64 return 0; 65 66 if (writes_addr(assigner)) 67 return 6; 68 69 /* handled via sync flags: */ 70 if (is_sfu(assigner) || is_tex(assigner) || is_mem(assigner)) 71 return 0; 72 73 /* assigner must be alu: */ 74 if (is_flow(consumer) || is_sfu(consumer) || is_tex(consumer) || 75 is_mem(consumer)) { 76 return 6; 77 } else if ((is_mad(consumer->opc) || is_madsh(consumer->opc)) && 78 (n == 3)) { 79 /* special case, 3rd src to cat3 not required on first cycle */ 80 return 1; 81 } else { 82 return 3; 83 } 84 } 85 86 void 87 ir3_insert_by_depth(struct ir3_instruction *instr, struct list_head *list) 88 { 89 /* remove from existing spot in list: */ 90 list_delinit(&instr->node); 91 92 /* find where to re-insert instruction: */ 93 list_for_each_entry (struct ir3_instruction, pos, list, node) { 94 if (pos->depth > instr->depth) { 95 list_add(&instr->node, &pos->node); 96 return; 97 } 98 } 99 /* if we get here, we didn't find an insertion spot: */ 100 list_addtail(&instr->node, list); 101 } 102 103 static void 104 ir3_instr_depth(struct ir3_instruction *instr) 105 { 106 struct ir3_instruction *src; 107 108 /* if we've already visited this instruction, bail now: */ 109 if (ir3_instr_check_mark(instr)) 110 return; 111 112 instr->depth = 0; 113 114 foreach_ssa_src_n(src, i, instr) { 115 unsigned sd; 116 117 /* visit child to compute it's depth: */ 118 ir3_instr_depth(src); 119 120 /* for array writes, no need to delay on previous write: */ 121 if (i == 0) 122 continue; 123 124 sd = ir3_delayslots(src, instr, i) + src->depth; 125 126 instr->depth = MAX2(instr->depth, sd); 127 } 128 129 if (!is_meta(instr)) 130 instr->depth++; 131 132 ir3_insert_by_depth(instr, &instr->block->instr_list); 133 } 134 135 static void 136 remove_unused_by_block(struct ir3_block *block) 137 { 138 list_for_each_entry_safe (struct ir3_instruction, instr, &block->instr_list, node) { 139 if (!ir3_instr_check_mark(instr)) { 140 if (instr->opc == OPC_END) 141 continue; 142 /* mark it, in case it is input, so we can 143 * remove unused inputs: 144 */ 145 instr->flags |= IR3_INSTR_UNUSED; 146 /* and remove from instruction list: */ 147 list_delinit(&instr->node); 148 } 149 } 150 } 151 152 void 153 ir3_depth(struct ir3 *ir) 154 { 155 unsigned i; 156 157 ir3_clear_mark(ir); 158 for (i = 0; i < ir->noutputs; i++) 159 if (ir->outputs[i]) 160 ir3_instr_depth(ir->outputs[i]); 161 162 for (i = 0; i < ir->keeps_count; i++) 163 ir3_instr_depth(ir->keeps[i]); 164 165 /* We also need to account for if-condition: */ 166 list_for_each_entry (struct ir3_block, block, &ir->block_list, node) { 167 if (block->condition) 168 ir3_instr_depth(block->condition); 169 } 170 171 /* mark un-used instructions: */ 172 list_for_each_entry (struct ir3_block, block, &ir->block_list, node) { 173 remove_unused_by_block(block); 174 } 175 176 /* note that we can end up with unused indirects, but we should 177 * not end up with unused predicates. 178 */ 179 for (i = 0; i < ir->indirects_count; i++) { 180 struct ir3_instruction *instr = ir->indirects[i]; 181 if (instr->flags & IR3_INSTR_UNUSED) 182 ir->indirects[i] = NULL; 183 } 184 185 /* cleanup unused inputs: */ 186 for (i = 0; i < ir->ninputs; i++) { 187 struct ir3_instruction *in = ir->inputs[i]; 188 if (in && (in->flags & IR3_INSTR_UNUSED)) 189 ir->inputs[i] = NULL; 190 } 191 } 192
