src/mesa/drivers/dri/r300/radeon_nqssadce.c

   1 /*
   2  * Copyright (C) 2008 Nicolai Haehnle.
   3  *
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining
   7  * a copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sublicense, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial
  16  * portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  21  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  22  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  */
  27
  28 /**
  29  * @file
  30  *
  31  * "Not-quite SSA" and Dead-Code Elimination.
  32  *
  33  * @note This code uses SWIZZLE_NIL in a source register to indicate that
  34  * the corresponding component is ignored by the corresponding instruction.
  35  */
  36
  37 #include "radeon_nqssadce.h"
  38
  39
  40 /**
  41  * Return the @ref register_state for the given register (or 0 for untracked
  42  * registers, i.e. constants).
  43  */
  44 static struct register_state *get_reg_state(struct nqssadce_state* s, GLuint file, GLuint index)
  45 {
  46         switch(file) {
  47         case PROGRAM_TEMPORARY: return &s->Temps[index];
  48         case PROGRAM_OUTPUT: return &s->Outputs[index];
  49         default: return 0;
  50         }
  51 }
  52
  53
  54 /**
  55  * Left multiplication of a register with a swizzle
  56  *
  57  * @note Works correctly only for X, Y, Z, W swizzles, not for constant swizzles.
  58  */
  59 static struct prog_src_register lmul_swizzle(GLuint swizzle, struct prog_src_register srcreg)
  60 {
  61         struct prog_src_register tmp = srcreg;
  62         int i;
  63         tmp.Swizzle = 0;
  64         tmp.Negate = NEGATE_NONE;
  65         for(i = 0; i < 4; ++i) {
  66                 GLuint swz = GET_SWZ(swizzle, i);
  67                 if (swz < 4) {
  68                         tmp.Swizzle |= GET_SWZ(srcreg.Swizzle, swz) << (i*3);
  69                         tmp.Negate |= GET_BIT(srcreg.Negate, swz) << i;
  70                 } else {
  71                         tmp.Swizzle |= swz << (i*3);
  72                 }
  73         }
  74         return tmp;
  75 }
  76
  77
  78 static struct prog_instruction* track_used_srcreg(struct nqssadce_state* s,
  79         struct prog_instruction *inst, GLint src, GLuint sourced)
  80 {
  81         int i;
  82         GLuint deswz_source = 0;
  83
  84         for(i = 0; i < 4; ++i) {
  85                 if (GET_BIT(sourced, i)) {
  86                         GLuint swz = GET_SWZ(inst->SrcReg[src].Swizzle, i);
  87                         deswz_source |= 1 << swz;
  88                 } else {
  89                         inst->SrcReg[src].Swizzle &= ~(7 << (3*i));
  90                         inst->SrcReg[src].Swizzle |= SWIZZLE_NIL << (3*i);
  91                 }
  92         }
  93
  94         if (!s->Descr->IsNativeSwizzle(inst->Opcode, inst->SrcReg[src])) {
  95                 struct prog_dst_register dstreg = inst->DstReg;
  96                 dstreg.File = PROGRAM_TEMPORARY;
  97                 dstreg.Index = _mesa_find_free_register(s->Program, PROGRAM_TEMPORARY);
  98                 dstreg.WriteMask = sourced;
  99
 100                 s->Descr->BuildSwizzle(s, dstreg, inst->SrcReg[src]);
 101
 102                 inst = s->Program->Instructions + s->IP;
 103                 inst->SrcReg[src].File = PROGRAM_TEMPORARY;
 104                 inst->SrcReg[src].Index = dstreg.Index;
 105                 inst->SrcReg[src].Swizzle = 0;
 106                 inst->SrcReg[src].Negate = NEGATE_NONE;
 107                 inst->SrcReg[src].Abs = 0;
 108                 for(i = 0; i < 4; ++i) {
 109                         if (GET_BIT(sourced, i))
 110                                 inst->SrcReg[src].Swizzle |= i << (3*i);
 111                         else
 112                                 inst->SrcReg[src].Swizzle |= SWIZZLE_NIL << (3*i);
 113                 }
 114                 deswz_source = sourced;
 115         }
 116
 117         struct register_state *regstate = get_reg_state(s, inst->SrcReg[src].File, inst->SrcReg[src].Index);
 118         if (regstate)
 119                 regstate->Sourced |= deswz_source & 0xf;
 120
 121         return inst;
 122 }
 123
 124
 125 static void rewrite_depth_out(struct prog_instruction *inst)
 126 {
 127         if (inst->DstReg.WriteMask & WRITEMASK_Z) {
 128                 inst->DstReg.WriteMask = WRITEMASK_W;
 129         } else {
 130                 inst->DstReg.WriteMask = 0;
 131                 return;
 132         }
 133
 134         switch (inst->Opcode) {
 135         case OPCODE_FRC:
 136         case OPCODE_MOV:
 137                 inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
 138                 break;
 139         case OPCODE_ADD:
 140         case OPCODE_MAX:
 141         case OPCODE_MIN:
 142         case OPCODE_MUL:
 143                 inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
 144                 inst->SrcReg[1] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[1]);
 145                 break;
 146         case OPCODE_CMP:
 147         case OPCODE_MAD:
 148                 inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
 149                 inst->SrcReg[1] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[1]);
 150                 inst->SrcReg[2] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[2]);
 151                 break;
 152         default:
 153                 // Scalar instructions needn't be reswizzled
 154                 break;
 155         }
 156 }
 157
 158 static void unalias_srcregs(struct prog_instruction *inst, GLuint oldindex, GLuint newindex)
 159 {
 160         int nsrc = _mesa_num_inst_src_regs(inst->Opcode);
 161         int i;
 162         for(i = 0; i < nsrc; ++i)
 163                 if (inst->SrcReg[i].File == PROGRAM_TEMPORARY && inst->SrcReg[i].Index == oldindex)
 164                         inst->SrcReg[i].Index = newindex;
 165 }
 166
 167 static void unalias_temporary(struct nqssadce_state* s, GLuint oldindex)
 168 {
 169         GLuint newindex = _mesa_find_free_register(s->Program, PROGRAM_TEMPORARY);
 170         int ip;
 171         for(ip = 0; ip < s->IP; ++ip) {
 172                 struct prog_instruction* inst = s->Program->Instructions + ip;
 173                 if (inst->DstReg.File == PROGRAM_TEMPORARY && inst->DstReg.Index == oldindex)
 174                         inst->DstReg.Index = newindex;
 175                 unalias_srcregs(inst, oldindex, newindex);
 176         }
 177         unalias_srcregs(s->Program->Instructions + s->IP, oldindex, newindex);
 178 }
 179
 180
 181 /**
 182  * Handle one instruction.
 183  */
 184 static void process_instruction(struct nqssadce_state* s)
 185 {
 186         struct prog_instruction *inst = s->Program->Instructions + s->IP;
 187
 188         if (inst->Opcode == OPCODE_END)
 189                 return;
 190
 191         if (inst->Opcode != OPCODE_KIL) {
 192                 if (s->Descr->RewriteDepthOut) {
 193                         if (inst->DstReg.File == PROGRAM_OUTPUT && inst->DstReg.Index == FRAG_RESULT_DEPTH)
 194                                 rewrite_depth_out(inst);
 195                 }
 196
 197                 struct register_state *regstate = get_reg_state(s, inst->DstReg.File, inst->DstReg.Index);
 198                 if (!regstate) {
 199                         _mesa_problem(s->Ctx, "NqssaDce: bad destination register (%i[%i])\n",
 200                                 inst->DstReg.File, inst->DstReg.Index);
 201                         return;
 202                 }
 203
 204                 inst->DstReg.WriteMask &= regstate->Sourced;
 205                 regstate->Sourced &= ~inst->DstReg.WriteMask;
 206
 207                 if (inst->DstReg.WriteMask == 0) {
 208                         _mesa_delete_instructions(s->Program, s->IP, 1);
 209                         return;
 210                 }
 211
 212                 if (inst->DstReg.File == PROGRAM_TEMPORARY && !regstate->Sourced)
 213                         unalias_temporary(s, inst->DstReg.Index);
 214         }
 215
 216         /* Attention: Due to swizzle emulation code, the following
 217          * might change the instruction stream under us, so we have
 218          * to be careful with the inst pointer. */
 219         switch (inst->Opcode) {
 220         case OPCODE_DDX:
 221         case OPCODE_DDY:
 222         case OPCODE_FRC:
 223         case OPCODE_MOV:
 224                 inst = track_used_srcreg(s, inst, 0, inst->DstReg.WriteMask);
 225                 break;
 226         case OPCODE_ADD:
 227         case OPCODE_MAX:
 228         case OPCODE_MIN:
 229         case OPCODE_MUL:
 230                 inst = track_used_srcreg(s, inst, 0, inst->DstReg.WriteMask);
 231                 inst = track_used_srcreg(s, inst, 1, inst->DstReg.WriteMask);
 232                 break;
 233         case OPCODE_CMP:
 234         case OPCODE_MAD:
 235                 inst = track_used_srcreg(s, inst, 0, inst->DstReg.WriteMask);
 236                 inst = track_used_srcreg(s, inst, 1, inst->DstReg.WriteMask);
 237                 inst = track_used_srcreg(s, inst, 2, inst->DstReg.WriteMask);
 238                 break;
 239         case OPCODE_COS:
 240         case OPCODE_EX2:
 241         case OPCODE_LG2:
 242         case OPCODE_RCP:
 243         case OPCODE_RSQ:
 244         case OPCODE_SIN:
 245                 inst = track_used_srcreg(s, inst, 0, 0x1);
 246                 break;
 247         case OPCODE_DP3:
 248                 inst = track_used_srcreg(s, inst, 0, 0x7);
 249                 inst = track_used_srcreg(s, inst, 1, 0x7);
 250                 break;
 251         case OPCODE_DP4:
 252                 inst = track_used_srcreg(s, inst, 0, 0xf);
 253                 inst = track_used_srcreg(s, inst, 1, 0xf);
 254                 break;
 255         case OPCODE_KIL:
 256         case OPCODE_TEX:
 257         case OPCODE_TXB:
 258         case OPCODE_TXP:
 259                 inst = track_used_srcreg(s, inst, 0, 0xf);
 260                 break;
 261         default:
 262                 _mesa_problem(s->Ctx, "NqssaDce: Unknown opcode %d\n", inst->Opcode);
 263                 return;
 264         }
 265 }
 266
 267
 268 void radeonNqssaDce(GLcontext *ctx, struct gl_program *p, struct radeon_nqssadce_descr* descr)
 269 {
 270         struct nqssadce_state s;
 271
 272         _mesa_bzero(&s, sizeof(s));
 273         s.Ctx = ctx;
 274         s.Program = p;
 275         s.Descr = descr;
 276         s.Descr->Init(&s);
 277         s.IP = p->NumInstructions;
 278
 279         while(s.IP > 0) {
 280                 s.IP--;
 281                 process_instruction(&s);
 282         }
 283 }