src/compiler/nir/nir_builder.h

   1 /*
   2  * Copyright © 2014-2015 Broadcom
   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
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #ifndef NIR_BUILDER_H
  25 #define NIR_BUILDER_H
  26
  27 #include "nir_control_flow.h"
  28
  29 struct exec_list;
  30
  31 typedef struct nir_builder {
  32    nir_cursor cursor;
  33
  34    nir_shader *shader;
  35    nir_function_impl *impl;
  36 } nir_builder;
  37
  38 static inline void
  39 nir_builder_init(nir_builder *build, nir_function_impl *impl)
  40 {
  41    memset(build, 0, sizeof(*build));
  42    build->impl = impl;
  43    build->shader = impl->function->shader;
  44 }
  45
  46 static inline void
  47 nir_builder_init_simple_shader(nir_builder *build, void *mem_ctx,
  48                                gl_shader_stage stage,
  49                                const nir_shader_compiler_options *options)
  50 {
  51    build->shader = nir_shader_create(mem_ctx, stage, options);
  52    nir_function *func = nir_function_create(build->shader, "main");
  53    build->impl = nir_function_impl_create(func);
  54    build->cursor = nir_after_cf_list(&build->impl->body);
  55 }
  56
  57 static inline void
  58 nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
  59 {
  60    nir_instr_insert(build->cursor, instr);
  61
  62    /* Move the cursor forward. */
  63    build->cursor = nir_after_instr(instr);
  64 }
  65
  66 static inline void
  67 nir_builder_cf_insert(nir_builder *build, nir_cf_node *cf)
  68 {
  69    nir_cf_node_insert(build->cursor, cf);
  70 }
  71
  72 static inline nir_ssa_def *
  73 nir_ssa_undef(nir_builder *build, unsigned num_components)
  74 {
  75    nir_ssa_undef_instr *undef =
  76       nir_ssa_undef_instr_create(build->shader, num_components);
  77    if (!undef)
  78       return NULL;
  79
  80    nir_instr_insert(nir_before_block(nir_start_block(build->impl)),
  81                     &undef->instr);
  82
  83    return &undef->def;
  84 }
  85
  86 static inline nir_ssa_def *
  87 nir_build_imm(nir_builder *build, unsigned num_components, nir_const_value value)
  88 {
  89    nir_load_const_instr *load_const =
  90       nir_load_const_instr_create(build->shader, num_components);
  91    if (!load_const)
  92       return NULL;
  93
  94    load_const->value = value;
  95
  96    nir_builder_instr_insert(build, &load_const->instr);
  97
  98    return &load_const->def;
  99 }
 100
 101 static inline nir_ssa_def *
 102 nir_imm_float(nir_builder *build, float x)
 103 {
 104    nir_const_value v;
 105
 106    memset(&v, 0, sizeof(v));
 107    v.f[0] = x;
 108
 109    return nir_build_imm(build, 1, v);
 110 }
 111
 112 static inline nir_ssa_def *
 113 nir_imm_vec4(nir_builder *build, float x, float y, float z, float w)
 114 {
 115    nir_const_value v;
 116
 117    memset(&v, 0, sizeof(v));
 118    v.f[0] = x;
 119    v.f[1] = y;
 120    v.f[2] = z;
 121    v.f[3] = w;
 122
 123    return nir_build_imm(build, 4, v);
 124 }
 125
 126 static inline nir_ssa_def *
 127 nir_imm_int(nir_builder *build, int x)
 128 {
 129    nir_const_value v;
 130
 131    memset(&v, 0, sizeof(v));
 132    v.i[0] = x;
 133
 134    return nir_build_imm(build, 1, v);
 135 }
 136
 137 static inline nir_ssa_def *
 138 nir_imm_ivec4(nir_builder *build, int x, int y, int z, int w)
 139 {
 140    nir_const_value v;
 141
 142    memset(&v, 0, sizeof(v));
 143    v.i[0] = x;
 144    v.i[1] = y;
 145    v.i[2] = z;
 146    v.i[3] = w;
 147
 148    return nir_build_imm(build, 4, v);
 149 }
 150
 151 static inline nir_ssa_def *
 152 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
 153               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
 154 {
 155    const nir_op_info *op_info = &nir_op_infos[op];
 156    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
 157    if (!instr)
 158       return NULL;
 159
 160    instr->src[0].src = nir_src_for_ssa(src0);
 161    if (src1)
 162       instr->src[1].src = nir_src_for_ssa(src1);
 163    if (src2)
 164       instr->src[2].src = nir_src_for_ssa(src2);
 165    if (src3)
 166       instr->src[3].src = nir_src_for_ssa(src3);
 167
 168    /* Guess the number of components the destination temporary should have
 169     * based on our input sizes, if it's not fixed for the op.
 170     */
 171    unsigned num_components = op_info->output_size;
 172    if (num_components == 0) {
 173       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 174          if (op_info->input_sizes[i] == 0)
 175             num_components = MAX2(num_components,
 176                                   instr->src[i].src.ssa->num_components);
 177       }
 178    }
 179    assert(num_components != 0);
 180
 181    /* Make sure we don't swizzle from outside of our source vector (like if a
 182     * scalar value was passed into a multiply with a vector).
 183     */
 184    for (unsigned i = 0; i < op_info->num_inputs; i++) {
 185       for (unsigned j = instr->src[i].src.ssa->num_components; j < 4; j++) {
 186          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
 187       }
 188    }
 189
 190    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components, NULL);
 191    instr->dest.write_mask = (1 << num_components) - 1;
 192
 193    nir_builder_instr_insert(build, &instr->instr);
 194
 195    return &instr->dest.dest.ssa;
 196 }
 197
 198 #define ALU1(op)                                                          \
 199 static inline nir_ssa_def *                                               \
 200 nir_##op(nir_builder *build, nir_ssa_def *src0)                           \
 201 {                                                                         \
 202    return nir_build_alu(build, nir_op_##op, src0, NULL, NULL, NULL);      \
 203 }
 204
 205 #define ALU2(op)                                                          \
 206 static inline nir_ssa_def *                                               \
 207 nir_##op(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)        \
 208 {                                                                         \
 209    return nir_build_alu(build, nir_op_##op, src0, src1, NULL, NULL);      \
 210 }
 211
 212 #define ALU3(op)                                                          \
 213 static inline nir_ssa_def *                                               \
 214 nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 215          nir_ssa_def *src1, nir_ssa_def *src2)                            \
 216 {                                                                         \
 217    return nir_build_alu(build, nir_op_##op, src0, src1, src2, NULL);      \
 218 }
 219
 220 #define ALU4(op)                                                          \
 221 static inline nir_ssa_def *                                               \
 222 nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 223          nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)         \
 224 {                                                                         \
 225    return nir_build_alu(build, nir_op_##op, src0, src1, src2, src3);      \
 226 }
 227
 228 #include "nir_builder_opcodes.h"
 229
 230 static inline nir_ssa_def *
 231 nir_vec(nir_builder *build, nir_ssa_def **comp, unsigned num_components)
 232 {
 233    switch (num_components) {
 234    case 4:
 235       return nir_vec4(build, comp[0], comp[1], comp[2], comp[3]);
 236    case 3:
 237       return nir_vec3(build, comp[0], comp[1], comp[2]);
 238    case 2:
 239       return nir_vec2(build, comp[0], comp[1]);
 240    case 1:
 241       return comp[0];
 242    default:
 243       unreachable("bad component count");
 244       return NULL;
 245    }
 246 }
 247
 248 /**
 249  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
 250  */
 251 static inline nir_ssa_def *
 252 nir_fmov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 253 {
 254    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_fmov);
 255    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components, NULL);
 256    mov->dest.write_mask = (1 << num_components) - 1;
 257    mov->src[0] = src;
 258    nir_builder_instr_insert(build, &mov->instr);
 259
 260    return &mov->dest.dest.ssa;
 261 }
 262
 263 static inline nir_ssa_def *
 264 nir_imov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 265 {
 266    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_imov);
 267    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components, NULL);
 268    mov->dest.write_mask = (1 << num_components) - 1;
 269    mov->src[0] = src;
 270    nir_builder_instr_insert(build, &mov->instr);
 271
 272    return &mov->dest.dest.ssa;
 273 }
 274
 275 /**
 276  * Construct an fmov or imov that reswizzles the source's components.
 277  */
 278 static inline nir_ssa_def *
 279 nir_swizzle(nir_builder *build, nir_ssa_def *src, unsigned swiz[4],
 280             unsigned num_components, bool use_fmov)
 281 {
 282    nir_alu_src alu_src = { NIR_SRC_INIT };
 283    alu_src.src = nir_src_for_ssa(src);
 284    for (unsigned i = 0; i < num_components; i++)
 285       alu_src.swizzle[i] = swiz[i];
 286
 287    return use_fmov ? nir_fmov_alu(build, alu_src, num_components) :
 288                      nir_imov_alu(build, alu_src, num_components);
 289 }
 290
 291 /* Selects the right fdot given the number of components in each source. */
 292 static inline nir_ssa_def *
 293 nir_fdot(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)
 294 {
 295    assert(src0->num_components == src1->num_components);
 296    switch (src0->num_components) {
 297    case 1: return nir_fmul(build, src0, src1);
 298    case 2: return nir_fdot2(build, src0, src1);
 299    case 3: return nir_fdot3(build, src0, src1);
 300    case 4: return nir_fdot4(build, src0, src1);
 301    default:
 302       unreachable("bad component size");
 303    }
 304
 305    return NULL;
 306 }
 307
 308 static inline nir_ssa_def *
 309 nir_channel(nir_builder *b, nir_ssa_def *def, unsigned c)
 310 {
 311    unsigned swizzle[4] = {c, c, c, c};
 312    return nir_swizzle(b, def, swizzle, 1, false);
 313 }
 314
 315 /**
 316  * Turns a nir_src into a nir_ssa_def * so it can be passed to
 317  * nir_build_alu()-based builder calls.
 318  *
 319  * See nir_ssa_for_alu_src() for alu instructions.
 320  */
 321 static inline nir_ssa_def *
 322 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
 323 {
 324    if (src.is_ssa && src.ssa->num_components == num_components)
 325       return src.ssa;
 326
 327    nir_alu_src alu = { NIR_SRC_INIT };
 328    alu.src = src;
 329    for (int j = 0; j < 4; j++)
 330       alu.swizzle[j] = j;
 331
 332    return nir_imov_alu(build, alu, num_components);
 333 }
 334
 335 /**
 336  * Similar to nir_ssa_for_src(), but for alu src's, respecting the
 337  * nir_alu_src's swizzle.
 338  */
 339 static inline nir_ssa_def *
 340 nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr *instr, unsigned srcn)
 341 {
 342    static uint8_t trivial_swizzle[4] = { 0, 1, 2, 3 };
 343    nir_alu_src *src = &instr->src[srcn];
 344    unsigned num_components = nir_ssa_alu_instr_src_components(instr, srcn);
 345
 346    if (src->src.is_ssa && (src->src.ssa->num_components == num_components) &&
 347        !src->abs && !src->negate &&
 348        (memcmp(src->swizzle, trivial_swizzle, num_components) == 0))
 349       return src->src.ssa;
 350
 351    return nir_imov_alu(build, *src, num_components);
 352 }
 353
 354 static inline nir_ssa_def *
 355 nir_load_var(nir_builder *build, nir_variable *var)
 356 {
 357    const unsigned num_components = glsl_get_vector_elements(var->type);
 358
 359    nir_intrinsic_instr *load =
 360       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_var);
 361    load->num_components = num_components;
 362    load->variables[0] = nir_deref_var_create(load, var);
 363    nir_ssa_dest_init(&load->instr, &load->dest, num_components, NULL);
 364    nir_builder_instr_insert(build, &load->instr);
 365    return &load->dest.ssa;
 366 }
 367
 368 static inline void
 369 nir_store_var(nir_builder *build, nir_variable *var, nir_ssa_def *value,
 370               unsigned writemask)
 371 {
 372    const unsigned num_components = glsl_get_vector_elements(var->type);
 373
 374    nir_intrinsic_instr *store =
 375       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_var);
 376    store->num_components = num_components;
 377    nir_intrinsic_set_write_mask(store, writemask);
 378    store->variables[0] = nir_deref_var_create(store, var);
 379    store->src[0] = nir_src_for_ssa(value);
 380    nir_builder_instr_insert(build, &store->instr);
 381 }
 382
 383 static inline void
 384 nir_store_deref_var(nir_builder *build, nir_deref_var *deref,
 385                     nir_ssa_def *value, unsigned writemask)
 386 {
 387    const unsigned num_components =
 388       glsl_get_vector_elements(nir_deref_tail(&deref->deref)->type);
 389
 390    nir_intrinsic_instr *store =
 391       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_var);
 392    store->num_components = num_components;
 393    store->const_index[0] = writemask & ((1 << num_components) - 1);
 394    store->variables[0] = nir_deref_as_var(nir_copy_deref(store, &deref->deref));
 395    store->src[0] = nir_src_for_ssa(value);
 396    nir_builder_instr_insert(build, &store->instr);
 397 }
 398
 399 static inline void
 400 nir_copy_deref_var(nir_builder *build, nir_deref_var *dest, nir_deref_var *src)
 401 {
 402    assert(nir_deref_tail(&dest->deref)->type ==
 403           nir_deref_tail(&src->deref)->type);
 404
 405    nir_intrinsic_instr *copy =
 406       nir_intrinsic_instr_create(build->shader, nir_intrinsic_copy_var);
 407    copy->variables[0] = nir_deref_as_var(nir_copy_deref(copy, &dest->deref));
 408    copy->variables[1] = nir_deref_as_var(nir_copy_deref(copy, &src->deref));
 409    nir_builder_instr_insert(build, &copy->instr);
 410 }
 411
 412 static inline void
 413 nir_copy_var(nir_builder *build, nir_variable *dest, nir_variable *src)
 414 {
 415    nir_intrinsic_instr *copy =
 416       nir_intrinsic_instr_create(build->shader, nir_intrinsic_copy_var);
 417    copy->variables[0] = nir_deref_var_create(copy, dest);
 418    copy->variables[1] = nir_deref_var_create(copy, src);
 419    nir_builder_instr_insert(build, &copy->instr);
 420 }
 421
 422 static inline nir_ssa_def *
 423 nir_load_system_value(nir_builder *build, nir_intrinsic_op op, int index)
 424 {
 425    nir_intrinsic_instr *load = nir_intrinsic_instr_create(build->shader, op);
 426    load->num_components = nir_intrinsic_infos[op].dest_components;
 427    load->const_index[0] = index;
 428    nir_ssa_dest_init(&load->instr, &load->dest,
 429                      nir_intrinsic_infos[op].dest_components, NULL);
 430    nir_builder_instr_insert(build, &load->instr);
 431    return &load->dest.ssa;
 432 }
 433
 434 static inline void
 435 nir_jump(nir_builder *build, nir_jump_type jump_type)
 436 {
 437    nir_jump_instr *jump = nir_jump_instr_create(build->shader, jump_type);
 438    nir_builder_instr_insert(build, &jump->instr);
 439 }
 440
 441 #endif /* NIR_BUILDER_H */