src/panfrost/bifrost/bi_pack.c

   1 /*
   2  * Copyright (C) 2020 Collabora, Ltd.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #include "compiler.h"
  25
  26 /* This file contains the final passes of the compiler. Running after
  27  * scheduling and RA, the IR is now finalized, so we need to emit it to actual
  28  * bits on the wire (as well as fixup branches) */
  29
  30 static uint64_t
  31 bi_pack_header(bi_clause *clause, bi_clause *next)
  32 {
  33         struct bifrost_header header = {
  34                 /* stub */
  35                 .no_end_of_shader = (next != NULL),
  36         };
  37
  38         uint64_t u = 0;
  39         memcpy(&u, &header, sizeof(header));
  40         return u;
  41 }
  42
  43 /* Represents the assignment of ports for a given bundle */
  44
  45 struct bi_registers {
  46         /* Register to assign to each port */
  47         unsigned port[4];
  48
  49         /* Read ports can be disabled */
  50         bool enabled[2];
  51
  52         /* Should we write FMA? what about ADD? If only a single port is
  53          * enabled it is in port 2, else ADD/FMA is 2/3 respectively */
  54         bool write_fma, write_add;
  55
  56         /* Should we read with port 3? */
  57         bool read_port3;
  58
  59         /* Packed uniform/constant */
  60         unsigned uniform_constant;
  61
  62         /* Whether writes are actually for the last instruction */
  63         bool first_instruction;
  64 };
  65
  66 /* Determines the register control field, ignoring the first? flag */
  67
  68 static enum bifrost_reg_control
  69 bi_pack_register_ctrl_lo(struct bi_registers r)
  70 {
  71         if (r.write_fma) {
  72                 if (r.write_add) {
  73                         assert(!r.read_port3);
  74                         return BIFROST_WRITE_ADD_P2_FMA_P3;
  75                 } else {
  76                         if (r.read_port3)
  77                                 return BIFROST_WRITE_FMA_P2_READ_P3;
  78                         else
  79                                 return BIFROST_WRITE_FMA_P2;
  80                 }
  81         } else if (r.write_add) {
  82                 if (r.read_port3)
  83                         return BIFROST_WRITE_ADD_P2_READ_P3;
  84                 else
  85                         return BIFROST_WRITE_ADD_P2;
  86         } else if (r.read_port3)
  87                 return BIFROST_READ_P3;
  88         else
  89                 return BIFROST_REG_NONE;
  90 }
  91
  92 /* Ditto but account for the first? flag this time */
  93
  94 static enum bifrost_reg_control
  95 bi_pack_register_ctrl(struct bi_registers r)
  96 {
  97         enum bifrost_reg_control ctrl = bi_pack_register_ctrl_lo(r);
  98
  99         if (r.first_instruction) {
 100                 if (ctrl == BIFROST_REG_NONE)
 101                         ctrl = BIFROST_FIRST_NONE;
 102                 else
 103                         ctrl |= BIFROST_FIRST_NONE;
 104         }
 105
 106         return ctrl;
 107 }
 108
 109 static uint64_t
 110 bi_pack_registers(struct bi_registers regs)
 111 {
 112         enum bifrost_reg_control ctrl = bi_pack_register_ctrl(regs);
 113         struct bifrost_regs s;
 114         uint64_t packed = 0;
 115
 116         if (regs.enabled[1]) {
 117                 /* Gotta save that bit!~ Required by the 63-x trick */
 118                 assert(regs.port[1] > regs.port[0]);
 119                 assert(regs.enabled[0]);
 120
 121                 /* Do the 63-x trick, see docs/disasm */
 122                 if (regs.port[0] > 31) {
 123                         regs.port[0] = 63 - regs.port[0];
 124                         regs.port[1] = 63 - regs.port[1];
 125                 }
 126
 127                 assert(regs.port[0] <= 31);
 128                 assert(regs.port[1] <= 63);
 129
 130                 s.ctrl = ctrl;
 131                 s.reg1 = regs.port[1];
 132                 s.reg0 = regs.port[0];
 133         } else {
 134                 /* Port 1 disabled, so set to zero and use port 1 for ctrl */
 135                 s.reg1 = ctrl << 2;
 136
 137                 if (regs.enabled[0]) {
 138                         /* Bit 0 upper bit of port 0 */
 139                         s.reg1 |= (regs.port[0] >> 5);
 140
 141                         /* Rest of port 0 in usual spot */
 142                         s.reg0 = (regs.port[0] & 0b11111);
 143                 } else {
 144                         /* Bit 1 set if port 0 also disabled */
 145                         s.reg1 |= (1 << 1);
 146                 }
 147         }
 148
 149         s.reg3 = regs.port[3];
 150         s.reg2 = regs.port[2];
 151         s.uniform_const = regs.uniform_constant;
 152
 153         memcpy(&packed, &s, sizeof(s));
 154         return packed;
 155 }
 156
 157 static unsigned
 158 bi_pack_fma(bi_clause *clause, bi_bundle bundle)
 159 {
 160         /* TODO */
 161         return BIFROST_FMA_NOP;
 162 }
 163
 164 static unsigned
 165 bi_pack_add(bi_clause *clause, bi_bundle bundle)
 166 {
 167         /* TODO */
 168         return BIFROST_ADD_NOP;
 169 }
 170
 171 struct bi_packed_bundle {
 172         uint64_t lo;
 173         uint64_t hi;
 174 };
 175
 176 static struct bi_packed_bundle
 177 bi_pack_bundle(bi_clause *clause, bi_bundle bundle)
 178 {
 179         struct bi_registers regs = {
 180                 .enabled = { true, true },
 181                 .port = { 34, 35, 3, 4 },
 182                 .write_fma = true,
 183                 .write_add = true,
 184                 .first_instruction = true,
 185         };
 186
 187         uint64_t reg = bi_pack_registers(regs);
 188         uint64_t fma = bi_pack_fma(clause, bundle);
 189         uint64_t add = bi_pack_add(clause, bundle);
 190
 191         struct bi_packed_bundle packed = {
 192                 .lo = reg | (fma << 35) | ((add & 0b111111) << 58),
 193                 .hi = add >> 6
 194         };
 195
 196         return packed;
 197 }
 198
 199 static void
 200 bi_pack_clause(bi_context *ctx, bi_clause *clause, bi_clause *next,
 201                 struct util_dynarray *emission)
 202 {
 203         struct bi_packed_bundle ins_1 = bi_pack_bundle(clause, clause->bundles[0]);
 204         assert(clause->bundle_count == 1);
 205
 206         struct bifrost_fmt1 quad_1 = {
 207                 .tag = BIFROST_FMT1_FINAL,
 208                 .header = bi_pack_header(clause, next),
 209                 .ins_1 = ins_1.lo,
 210                 .ins_2 = ins_1.hi & ((1 << 11) - 1),
 211                 .ins_0 = (ins_1.hi >> 11) & 0b111,
 212         };
 213
 214         util_dynarray_append(emission, struct bifrost_fmt1, quad_1);
 215 }
 216
 217 static bi_clause *
 218 bi_next_clause(bi_context *ctx, pan_block *block, bi_clause *clause)
 219 {
 220         /* Try the next clause in this block */
 221         if (clause->link.next != &((bi_block *) block)->clauses)
 222                 return list_first_entry(&(clause->link), bi_clause, link);
 223
 224         /* Try the next block, or the one after that if it's empty, etc .*/
 225         pan_block *next_block = pan_next_block(block);
 226
 227         bi_foreach_block_from(ctx, next_block, block) {
 228                 bi_block *blk = (bi_block *) block;
 229
 230                 if (!list_is_empty(&blk->clauses))
 231                         return list_first_entry(&(blk->clauses), bi_clause, link);
 232         }
 233
 234         return NULL;
 235 }
 236
 237 void
 238 bi_pack(bi_context *ctx, struct util_dynarray *emission)
 239 {
 240         util_dynarray_init(emission, NULL);
 241
 242         bi_foreach_block(ctx, _block) {
 243                 bi_block *block = (bi_block *) _block;
 244
 245                 bi_foreach_clause_in_block(block, clause) {
 246                         bi_clause *next = bi_next_clause(ctx, _block, clause);
 247                         bi_pack_clause(ctx, clause, next, emission);
 248                 }
 249         }
 250 }