src/mesa/drivers/dri/i965/brw_vs.c

   1 /*
   2  Copyright (C) Intel Corp.  2006.  All Rights Reserved.
   3  Intel funded Tungsten Graphics to
   4  develop this 3D driver.
   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   * Authors:
  29   *   Keith Whitwell <keithw@vmware.com>
  30   */
  31
  32
  33 #include "main/compiler.h"
  34 #include "brw_context.h"
  35 #include "brw_vs.h"
  36 #include "brw_util.h"
  37 #include "brw_state.h"
  38 #include "program/prog_print.h"
  39 #include "program/prog_parameter.h"
  40
  41 #include "util/ralloc.h"
  42
  43 static inline void assign_vue_slot(struct brw_vue_map *vue_map,
  44                                    int varying)
  45 {
  46    /* Make sure this varying hasn't been assigned a slot already */
  47    assert (vue_map->varying_to_slot[varying] == -1);
  48
  49    vue_map->varying_to_slot[varying] = vue_map->num_slots;
  50    vue_map->slot_to_varying[vue_map->num_slots++] = varying;
  51 }
  52
  53 /**
  54  * Compute the VUE map for vertex shader program.
  55  */
  56 void
  57 brw_compute_vue_map(struct brw_context *brw, struct brw_vue_map *vue_map,
  58                     GLbitfield64 slots_valid)
  59 {
  60    vue_map->slots_valid = slots_valid;
  61    int i;
  62
  63    /* gl_Layer and gl_ViewportIndex don't get their own varying slots -- they
  64     * are stored in the first VUE slot (VARYING_SLOT_PSIZ).
  65     */
  66    slots_valid &= ~(VARYING_BIT_LAYER | VARYING_BIT_VIEWPORT);
  67
  68    /* Make sure that the values we store in vue_map->varying_to_slot and
  69     * vue_map->slot_to_varying won't overflow the signed chars that are used
  70     * to store them.  Note that since vue_map->slot_to_varying sometimes holds
  71     * values equal to BRW_VARYING_SLOT_COUNT, we need to ensure that
  72     * BRW_VARYING_SLOT_COUNT is <= 127, not 128.
  73     */
  74    STATIC_ASSERT(BRW_VARYING_SLOT_COUNT <= 127);
  75
  76    vue_map->num_slots = 0;
  77    for (i = 0; i < BRW_VARYING_SLOT_COUNT; ++i) {
  78       vue_map->varying_to_slot[i] = -1;
  79       vue_map->slot_to_varying[i] = BRW_VARYING_SLOT_COUNT;
  80    }
  81
  82    /* VUE header: format depends on chip generation and whether clipping is
  83     * enabled.
  84     */
  85    if (brw->gen < 6) {
  86       /* There are 8 dwords in VUE header pre-Ironlake:
  87        * dword 0-3 is indices, point width, clip flags.
  88        * dword 4-7 is ndc position
  89        * dword 8-11 is the first vertex data.
  90        *
  91        * On Ironlake the VUE header is nominally 20 dwords, but the hardware
  92        * will accept the same header layout as Gen4 [and should be a bit faster]
  93        */
  94       assign_vue_slot(vue_map, VARYING_SLOT_PSIZ);
  95       assign_vue_slot(vue_map, BRW_VARYING_SLOT_NDC);
  96       assign_vue_slot(vue_map, VARYING_SLOT_POS);
  97    } else {
  98       /* There are 8 or 16 DWs (D0-D15) in VUE header on Sandybridge:
  99        * dword 0-3 of the header is indices, point width, clip flags.
 100        * dword 4-7 is the 4D space position
 101        * dword 8-15 of the vertex header is the user clip distance if
 102        * enabled.
 103        * dword 8-11 or 16-19 is the first vertex element data we fill.
 104        */
 105       assign_vue_slot(vue_map, VARYING_SLOT_PSIZ);
 106       assign_vue_slot(vue_map, VARYING_SLOT_POS);
 107       if (slots_valid & BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0))
 108          assign_vue_slot(vue_map, VARYING_SLOT_CLIP_DIST0);
 109       if (slots_valid & BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1))
 110          assign_vue_slot(vue_map, VARYING_SLOT_CLIP_DIST1);
 111
 112       /* front and back colors need to be consecutive so that we can use
 113        * ATTRIBUTE_SWIZZLE_INPUTATTR_FACING to swizzle them when doing
 114        * two-sided color.
 115        */
 116       if (slots_valid & BITFIELD64_BIT(VARYING_SLOT_COL0))
 117          assign_vue_slot(vue_map, VARYING_SLOT_COL0);
 118       if (slots_valid & BITFIELD64_BIT(VARYING_SLOT_BFC0))
 119          assign_vue_slot(vue_map, VARYING_SLOT_BFC0);
 120       if (slots_valid & BITFIELD64_BIT(VARYING_SLOT_COL1))
 121          assign_vue_slot(vue_map, VARYING_SLOT_COL1);
 122       if (slots_valid & BITFIELD64_BIT(VARYING_SLOT_BFC1))
 123          assign_vue_slot(vue_map, VARYING_SLOT_BFC1);
 124    }
 125
 126    /* The hardware doesn't care about the rest of the vertex outputs, so just
 127     * assign them contiguously.  Don't reassign outputs that already have a
 128     * slot.
 129     *
 130     * We generally don't need to assign a slot for VARYING_SLOT_CLIP_VERTEX,
 131     * since it's encoded as the clip distances by emit_clip_distances().
 132     * However, it may be output by transform feedback, and we'd rather not
 133     * recompute state when TF changes, so we just always include it.
 134     */
 135    for (int i = 0; i < VARYING_SLOT_MAX; ++i) {
 136       if ((slots_valid & BITFIELD64_BIT(i)) &&
 137           vue_map->varying_to_slot[i] == -1) {
 138          assign_vue_slot(vue_map, i);
 139       }
 140    }
 141 }
 142
 143
 144 /**
 145  * Decide which set of clip planes should be used when clipping via
 146  * gl_Position or gl_ClipVertex.
 147  */
 148 gl_clip_plane *brw_select_clip_planes(struct gl_context *ctx)
 149 {
 150    if (ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX]) {
 151       /* There is currently a GLSL vertex shader, so clip according to GLSL
 152        * rules, which means compare gl_ClipVertex (or gl_Position, if
 153        * gl_ClipVertex wasn't assigned) against the eye-coordinate clip planes
 154        * that were stored in EyeUserPlane at the time the clip planes were
 155        * specified.
 156        */
 157       return ctx->Transform.EyeUserPlane;
 158    } else {
 159       /* Either we are using fixed function or an ARB vertex program.  In
 160        * either case the clip planes are going to be compared against
 161        * gl_Position (which is in clip coordinates) so we have to clip using
 162        * _ClipUserPlane, which was transformed into clip coordinates by Mesa
 163        * core.
 164        */
 165       return ctx->Transform._ClipUserPlane;
 166    }
 167 }
 168
 169
 170 bool
 171 brw_vs_prog_data_compare(const void *in_a, const void *in_b)
 172 {
 173    const struct brw_vs_prog_data *a = in_a;
 174    const struct brw_vs_prog_data *b = in_b;
 175
 176    /* Compare the base structure. */
 177    if (!brw_stage_prog_data_compare(&a->base.base, &b->base.base))
 178       return false;
 179
 180    /* Compare the rest of the struct. */
 181    const unsigned offset = sizeof(struct brw_stage_prog_data);
 182    if (memcmp(((char *) a) + offset, ((char *) b) + offset,
 183               sizeof(struct brw_vs_prog_data) - offset)) {
 184       return false;
 185    }
 186
 187    return true;
 188 }
 189
 190 static bool
 191 do_vs_prog(struct brw_context *brw,
 192            struct gl_shader_program *prog,
 193            struct brw_vertex_program *vp,
 194            struct brw_vs_prog_key *key)
 195 {
 196    GLuint program_size;
 197    const GLuint *program;
 198    struct brw_vs_compile c;
 199    struct brw_vs_prog_data prog_data;
 200    struct brw_stage_prog_data *stage_prog_data = &prog_data.base.base;
 201    void *mem_ctx;
 202    int i;
 203    struct gl_shader *vs = NULL;
 204
 205    if (prog)
 206       vs = prog->_LinkedShaders[MESA_SHADER_VERTEX];
 207
 208    memset(&c, 0, sizeof(c));
 209    memcpy(&c.key, key, sizeof(*key));
 210    memset(&prog_data, 0, sizeof(prog_data));
 211
 212    /* Use ALT floating point mode for ARB programs so that 0^0 == 1. */
 213    if (!prog)
 214       stage_prog_data->use_alt_mode = true;
 215
 216    mem_ctx = ralloc_context(NULL);
 217
 218    c.vp = vp;
 219
 220    /* Allocate the references to the uniforms that will end up in the
 221     * prog_data associated with the compiled program, and which will be freed
 222     * by the state cache.
 223     */
 224    int param_count;
 225    if (vs) {
 226       /* We add padding around uniform values below vec4 size, with the worst
 227        * case being a float value that gets blown up to a vec4, so be
 228        * conservative here.
 229        */
 230       param_count = vs->num_uniform_components * 4;
 231
 232    } else {
 233       param_count = vp->program.Base.Parameters->NumParameters * 4;
 234    }
 235    /* vec4_visitor::setup_uniform_clipplane_values() also uploads user clip
 236     * planes as uniforms.
 237     */
 238    param_count += c.key.base.nr_userclip_plane_consts * 4;
 239
 240    stage_prog_data->param =
 241       rzalloc_array(NULL, const gl_constant_value *, param_count);
 242    stage_prog_data->pull_param =
 243       rzalloc_array(NULL, const gl_constant_value *, param_count);
 244    stage_prog_data->nr_params = param_count;
 245
 246    GLbitfield64 outputs_written = vp->program.Base.OutputsWritten;
 247    prog_data.inputs_read = vp->program.Base.InputsRead;
 248
 249    if (c.key.copy_edgeflag) {
 250       outputs_written |= BITFIELD64_BIT(VARYING_SLOT_EDGE);
 251       prog_data.inputs_read |= VERT_BIT_EDGEFLAG;
 252    }
 253
 254    if (brw->gen < 6) {
 255       /* Put dummy slots into the VUE for the SF to put the replaced
 256        * point sprite coords in.  We shouldn't need these dummy slots,
 257        * which take up precious URB space, but it would mean that the SF
 258        * doesn't get nice aligned pairs of input coords into output
 259        * coords, which would be a pain to handle.
 260        */
 261       for (i = 0; i < 8; i++) {
 262          if (c.key.point_coord_replace & (1 << i))
 263             outputs_written |= BITFIELD64_BIT(VARYING_SLOT_TEX0 + i);
 264       }
 265
 266       /* if back colors are written, allocate slots for front colors too */
 267       if (outputs_written & BITFIELD64_BIT(VARYING_SLOT_BFC0))
 268          outputs_written |= BITFIELD64_BIT(VARYING_SLOT_COL0);
 269       if (outputs_written & BITFIELD64_BIT(VARYING_SLOT_BFC1))
 270          outputs_written |= BITFIELD64_BIT(VARYING_SLOT_COL1);
 271    }
 272
 273    /* In order for legacy clipping to work, we need to populate the clip
 274     * distance varying slots whenever clipping is enabled, even if the vertex
 275     * shader doesn't write to gl_ClipDistance.
 276     */
 277    if (c.key.base.userclip_active) {
 278       outputs_written |= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0);
 279       outputs_written |= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1);
 280    }
 281
 282    brw_compute_vue_map(brw, &prog_data.base.vue_map, outputs_written);
 283
 284    if (0) {
 285       _mesa_fprint_program_opt(stderr, &c.vp->program.Base, PROG_PRINT_DEBUG,
 286                                true);
 287    }
 288
 289    /* Emit GEN4 code.
 290     */
 291    program = brw_vs_emit(brw, prog, &c, &prog_data, mem_ctx, &program_size);
 292    if (program == NULL) {
 293       ralloc_free(mem_ctx);
 294       return false;
 295    }
 296
 297    /* Scratch space is used for register spilling */
 298    if (c.base.last_scratch) {
 299       perf_debug("Vertex shader triggered register spilling.  "
 300                  "Try reducing the number of live vec4 values to "
 301                  "improve performance.\n");
 302
 303       prog_data.base.base.total_scratch
 304          = brw_get_scratch_size(c.base.last_scratch*REG_SIZE);
 305
 306       brw_get_scratch_bo(brw, &brw->vs.base.scratch_bo,
 307                          prog_data.base.base.total_scratch *
 308                          brw->max_vs_threads);
 309    }
 310
 311    brw_upload_cache(&brw->cache, BRW_CACHE_VS_PROG,
 312                     &c.key, sizeof(c.key),
 313                     program, program_size,
 314                     &prog_data, sizeof(prog_data),
 315                     &brw->vs.base.prog_offset, &brw->vs.prog_data);
 316    ralloc_free(mem_ctx);
 317
 318    return true;
 319 }
 320
 321 static bool
 322 key_debug(struct brw_context *brw, const char *name, int a, int b)
 323 {
 324    if (a != b) {
 325       perf_debug("  %s %d->%d\n", name, a, b);
 326       return true;
 327    }
 328    return false;
 329 }
 330
 331 void
 332 brw_vs_debug_recompile(struct brw_context *brw,
 333                        struct gl_shader_program *prog,
 334                        const struct brw_vs_prog_key *key)
 335 {
 336    struct brw_cache_item *c = NULL;
 337    const struct brw_vs_prog_key *old_key = NULL;
 338    bool found = false;
 339
 340    perf_debug("Recompiling vertex shader for program %d\n", prog->Name);
 341
 342    for (unsigned int i = 0; i < brw->cache.size; i++) {
 343       for (c = brw->cache.items[i]; c; c = c->next) {
 344          if (c->cache_id == BRW_CACHE_VS_PROG) {
 345             old_key = c->key;
 346
 347             if (old_key->base.program_string_id == key->base.program_string_id)
 348                break;
 349          }
 350       }
 351       if (c)
 352          break;
 353    }
 354
 355    if (!c) {
 356       perf_debug("  Didn't find previous compile in the shader cache for "
 357                  "debug\n");
 358       return;
 359    }
 360
 361    for (unsigned int i = 0; i < VERT_ATTRIB_MAX; i++) {
 362       found |= key_debug(brw, "Vertex attrib w/a flags",
 363                          old_key->gl_attrib_wa_flags[i],
 364                          key->gl_attrib_wa_flags[i]);
 365    }
 366
 367    found |= key_debug(brw, "user clip flags",
 368                       old_key->base.userclip_active, key->base.userclip_active);
 369
 370    found |= key_debug(brw, "user clipping planes as push constants",
 371                       old_key->base.nr_userclip_plane_consts,
 372                       key->base.nr_userclip_plane_consts);
 373
 374    found |= key_debug(brw, "copy edgeflag",
 375                       old_key->copy_edgeflag, key->copy_edgeflag);
 376    found |= key_debug(brw, "PointCoord replace",
 377                       old_key->point_coord_replace, key->point_coord_replace);
 378    found |= key_debug(brw, "vertex color clamping",
 379                       old_key->clamp_vertex_color, key->clamp_vertex_color);
 380
 381    found |= brw_debug_recompile_sampler_key(brw, &old_key->base.tex,
 382                                             &key->base.tex);
 383
 384    if (!found) {
 385       perf_debug("  Something else\n");
 386    }
 387 }
 388
 389
 390 void
 391 brw_setup_vue_key_clip_info(struct brw_context *brw,
 392                             struct brw_vue_prog_key *key,
 393                             bool program_uses_clip_distance)
 394 {
 395    struct gl_context *ctx = &brw->ctx;
 396
 397    key->userclip_active = (ctx->Transform.ClipPlanesEnabled != 0);
 398    if (key->userclip_active && !program_uses_clip_distance) {
 399       key->nr_userclip_plane_consts
 400          = _mesa_logbase2(ctx->Transform.ClipPlanesEnabled) + 1;
 401    }
 402 }
 403
 404 static bool
 405 brw_vs_state_dirty(struct brw_context *brw)
 406 {
 407    return brw_state_dirty(brw,
 408                           _NEW_BUFFERS |
 409                           _NEW_LIGHT |
 410                           _NEW_POINT |
 411                           _NEW_POLYGON |
 412                           _NEW_TEXTURE |
 413                           _NEW_TRANSFORM,
 414                           BRW_NEW_VERTEX_PROGRAM |
 415                           BRW_NEW_VS_ATTRIB_WORKAROUNDS);
 416 }
 417
 418 static void
 419 brw_vs_populate_key(struct brw_context *brw,
 420                     struct brw_vs_prog_key *key)
 421 {
 422    struct gl_context *ctx = &brw->ctx;
 423    /* BRW_NEW_VERTEX_PROGRAM */
 424    struct brw_vertex_program *vp =
 425       (struct brw_vertex_program *)brw->vertex_program;
 426    struct gl_program *prog = (struct gl_program *) brw->vertex_program;
 427    int i;
 428
 429    memset(key, 0, sizeof(*key));
 430
 431    /* Just upload the program verbatim for now.  Always send it all
 432     * the inputs it asks for, whether they are varying or not.
 433     */
 434    key->base.program_string_id = vp->id;
 435    brw_setup_vue_key_clip_info(brw, &key->base,
 436                                vp->program.Base.UsesClipDistanceOut);
 437
 438    /* _NEW_POLYGON */
 439    if (brw->gen < 6) {
 440       key->copy_edgeflag = (ctx->Polygon.FrontMode != GL_FILL ||
 441                             ctx->Polygon.BackMode != GL_FILL);
 442    }
 443
 444    if (prog->OutputsWritten & (VARYING_BIT_COL0 | VARYING_BIT_COL1 |
 445                                VARYING_BIT_BFC0 | VARYING_BIT_BFC1)) {
 446       /* _NEW_LIGHT | _NEW_BUFFERS */
 447       key->clamp_vertex_color = ctx->Light._ClampVertexColor;
 448    }
 449
 450    /* _NEW_POINT */
 451    if (brw->gen < 6 && ctx->Point.PointSprite) {
 452       for (i = 0; i < 8; i++) {
 453          if (ctx->Point.CoordReplace[i])
 454             key->point_coord_replace |= (1 << i);
 455       }
 456    }
 457
 458    /* _NEW_TEXTURE */
 459    brw_populate_sampler_prog_key_data(ctx, prog, brw->vs.base.sampler_count,
 460                                       &key->base.tex);
 461
 462    /* BRW_NEW_VS_ATTRIB_WORKAROUNDS */
 463    memcpy(key->gl_attrib_wa_flags, brw->vb.attrib_wa_flags,
 464           sizeof(brw->vb.attrib_wa_flags));
 465 }
 466
 467 void
 468 brw_upload_vs_prog(struct brw_context *brw)
 469 {
 470    struct gl_context *ctx = &brw->ctx;
 471    struct brw_vs_prog_key key;
 472    /* BRW_NEW_VERTEX_PROGRAM */
 473    struct brw_vertex_program *vp =
 474       (struct brw_vertex_program *)brw->vertex_program;
 475
 476    if (!brw_vs_state_dirty(brw))
 477       return;
 478
 479    brw_vs_populate_key(brw, &key);
 480
 481    if (!brw_search_cache(&brw->cache, BRW_CACHE_VS_PROG,
 482                          &key, sizeof(key),
 483                          &brw->vs.base.prog_offset, &brw->vs.prog_data)) {
 484       bool success =
 485          do_vs_prog(brw, ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX], vp,
 486                     &key);
 487       (void) success;
 488       assert(success);
 489    }
 490    brw->vs.base.prog_data = &brw->vs.prog_data->base.base;
 491
 492    if (memcmp(&brw->vs.prog_data->base.vue_map, &brw->vue_map_geom_out,
 493               sizeof(brw->vue_map_geom_out)) != 0) {
 494       brw->vue_map_vs = brw->vs.prog_data->base.vue_map;
 495       brw->ctx.NewDriverState |= BRW_NEW_VUE_MAP_VS;
 496       if (brw->gen < 6) {
 497          /* No geometry shader support, so the VS VUE map is the VUE map for
 498           * the output of the "geometry" portion of the pipeline.
 499           */
 500          brw->vue_map_geom_out = brw->vue_map_vs;
 501          brw->ctx.NewDriverState |= BRW_NEW_VUE_MAP_GEOM_OUT;
 502       }
 503    }
 504 }
 505
 506 bool
 507 brw_vs_precompile(struct gl_context *ctx,
 508                   struct gl_shader_program *shader_prog,
 509                   struct gl_program *prog)
 510 {
 511    struct brw_context *brw = brw_context(ctx);
 512    struct brw_vs_prog_key key;
 513    uint32_t old_prog_offset = brw->vs.base.prog_offset;
 514    struct brw_vs_prog_data *old_prog_data = brw->vs.prog_data;
 515    bool success;
 516
 517    struct gl_vertex_program *vp = (struct gl_vertex_program *) prog;
 518    struct brw_vertex_program *bvp = brw_vertex_program(vp);
 519
 520    memset(&key, 0, sizeof(key));
 521
 522    brw_vue_setup_prog_key_for_precompile(ctx, &key.base, bvp->id, &vp->Base);
 523    key.clamp_vertex_color =
 524       (prog->OutputsWritten & (VARYING_BIT_COL0 | VARYING_BIT_COL1 |
 525                                VARYING_BIT_BFC0 | VARYING_BIT_BFC1));
 526
 527    success = do_vs_prog(brw, shader_prog, bvp, &key);
 528
 529    brw->vs.base.prog_offset = old_prog_offset;
 530    brw->vs.prog_data = old_prog_data;
 531
 532    return success;
 533 }