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_build_imm(nir_builder *build, unsigned num_components, nir_const_value value)
  74 {
  75    nir_load_const_instr *load_const =
  76       nir_load_const_instr_create(build->shader, num_components);
  77    if (!load_const)
  78       return NULL;
  79
  80    load_const->value = value;
  81
  82    nir_builder_instr_insert(build, &load_const->instr);
  83
  84    return &load_const->def;
  85 }
  86
  87 static inline nir_ssa_def *
  88 nir_imm_float(nir_builder *build, float x)
  89 {
  90    nir_const_value v;
  91
  92    memset(&v, 0, sizeof(v));
  93    v.f32[0] = x;
  94
  95    return nir_build_imm(build, 1, v);
  96 }
  97
  98 static inline nir_ssa_def *
  99 nir_imm_vec4(nir_builder *build, float x, float y, float z, float w)
 100 {
 101    nir_const_value v;
 102
 103    memset(&v, 0, sizeof(v));
 104    v.f32[0] = x;
 105    v.f32[1] = y;
 106    v.f32[2] = z;
 107    v.f32[3] = w;
 108
 109    return nir_build_imm(build, 4, v);
 110 }
 111
 112 static inline nir_ssa_def *
 113 nir_imm_int(nir_builder *build, int x)
 114 {
 115    nir_const_value v;
 116
 117    memset(&v, 0, sizeof(v));
 118    v.i32[0] = x;
 119
 120    return nir_build_imm(build, 1, v);
 121 }
 122
 123 static inline nir_ssa_def *
 124 nir_imm_ivec4(nir_builder *build, int x, int y, int z, int w)
 125 {
 126    nir_const_value v;
 127
 128    memset(&v, 0, sizeof(v));
 129    v.i32[0] = x;
 130    v.i32[1] = y;
 131    v.i32[2] = z;
 132    v.i32[3] = w;
 133
 134    return nir_build_imm(build, 4, v);
 135 }
 136
 137 static inline nir_ssa_def *
 138 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
 139               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
 140 {
 141    const nir_op_info *op_info = &nir_op_infos[op];
 142    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
 143    if (!instr)
 144       return NULL;
 145
 146    instr->src[0].src = nir_src_for_ssa(src0);
 147    if (src1)
 148       instr->src[1].src = nir_src_for_ssa(src1);
 149    if (src2)
 150       instr->src[2].src = nir_src_for_ssa(src2);
 151    if (src3)
 152       instr->src[3].src = nir_src_for_ssa(src3);
 153
 154    /* Guess the number of components the destination temporary should have
 155     * based on our input sizes, if it's not fixed for the op.
 156     */
 157    unsigned num_components = op_info->output_size;
 158    if (num_components == 0) {
 159       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 160          if (op_info->input_sizes[i] == 0)
 161             num_components = MAX2(num_components,
 162                                   instr->src[i].src.ssa->num_components);
 163       }
 164    }
 165    assert(num_components != 0);
 166
 167    /* Make sure we don't swizzle from outside of our source vector (like if a
 168     * scalar value was passed into a multiply with a vector).
 169     */
 170    for (unsigned i = 0; i < op_info->num_inputs; i++) {
 171       for (unsigned j = instr->src[i].src.ssa->num_components; j < 4; j++) {
 172          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
 173       }
 174    }
 175
 176    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components, NULL);
 177    instr->dest.write_mask = (1 << num_components) - 1;
 178
 179    nir_builder_instr_insert(build, &instr->instr);
 180
 181    return &instr->dest.dest.ssa;
 182 }
 183
 184 #define ALU1(op)                                                          \
 185 static inline nir_ssa_def *                                               \
 186 nir_##op(nir_builder *build, nir_ssa_def *src0)                           \
 187 {                                                                         \
 188    return nir_build_alu(build, nir_op_##op, src0, NULL, NULL, NULL);      \
 189 }
 190
 191 #define ALU2(op)                                                          \
 192 static inline nir_ssa_def *                                               \
 193 nir_##op(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)        \
 194 {                                                                         \
 195    return nir_build_alu(build, nir_op_##op, src0, src1, NULL, NULL);      \
 196 }
 197
 198 #define ALU3(op)                                                          \
 199 static inline nir_ssa_def *                                               \
 200 nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 201          nir_ssa_def *src1, nir_ssa_def *src2)                            \
 202 {                                                                         \
 203    return nir_build_alu(build, nir_op_##op, src0, src1, src2, NULL);      \
 204 }
 205
 206 #define ALU4(op)                                                          \
 207 static inline nir_ssa_def *                                               \
 208 nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 209          nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)         \
 210 {                                                                         \
 211    return nir_build_alu(build, nir_op_##op, src0, src1, src2, src3);      \
 212 }
 213
 214 #include "nir_builder_opcodes.h"
 215
 216 static inline nir_ssa_def *
 217 nir_vec(nir_builder *build, nir_ssa_def **comp, unsigned num_components)
 218 {
 219    switch (num_components) {
 220    case 4:
 221       return nir_vec4(build, comp[0], comp[1], comp[2], comp[3]);
 222    case 3:
 223       return nir_vec3(build, comp[0], comp[1], comp[2]);
 224    case 2:
 225       return nir_vec2(build, comp[0], comp[1]);
 226    case 1:
 227       return comp[0];
 228    default:
 229       unreachable("bad component count");
 230       return NULL;
 231    }
 232 }
 233
 234 /**
 235  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
 236  */
 237 static inline nir_ssa_def *
 238 nir_fmov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 239 {
 240    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_fmov);
 241    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components, NULL);
 242    mov->dest.write_mask = (1 << num_components) - 1;
 243    mov->src[0] = src;
 244    nir_builder_instr_insert(build, &mov->instr);
 245
 246    return &mov->dest.dest.ssa;
 247 }
 248
 249 static inline nir_ssa_def *
 250 nir_imov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 251 {
 252    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_imov);
 253    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components, NULL);
 254    mov->dest.write_mask = (1 << num_components) - 1;
 255    mov->src[0] = src;
 256    nir_builder_instr_insert(build, &mov->instr);
 257
 258    return &mov->dest.dest.ssa;
 259 }
 260
 261 /**
 262  * Construct an fmov or imov that reswizzles the source's components.
 263  */
 264 static inline nir_ssa_def *
 265 nir_swizzle(nir_builder *build, nir_ssa_def *src, unsigned swiz[4],
 266             unsigned num_components, bool use_fmov)
 267 {
 268    nir_alu_src alu_src = { NIR_SRC_INIT };
 269    alu_src.src = nir_src_for_ssa(src);
 270    for (unsigned i = 0; i < num_components; i++)
 271       alu_src.swizzle[i] = swiz[i];
 272
 273    return use_fmov ? nir_fmov_alu(build, alu_src, num_components) :
 274                      nir_imov_alu(build, alu_src, num_components);
 275 }
 276
 277 static inline nir_ssa_def *
 278 nir_channel(nir_builder *b, nir_ssa_def *def, unsigned c)
 279 {
 280    unsigned swizzle[4] = {c, c, c, c};
 281    return nir_swizzle(b, def, swizzle, 1, false);
 282 }
 283
 284 /**
 285  * Turns a nir_src into a nir_ssa_def * so it can be passed to
 286  * nir_build_alu()-based builder calls.
 287  *
 288  * See nir_ssa_for_alu_src() for alu instructions.
 289  */
 290 static inline nir_ssa_def *
 291 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
 292 {
 293    if (src.is_ssa && src.ssa->num_components == num_components)
 294       return src.ssa;
 295
 296    nir_alu_src alu = { NIR_SRC_INIT };
 297    alu.src = src;
 298    for (int j = 0; j < 4; j++)
 299       alu.swizzle[j] = j;
 300
 301    return nir_imov_alu(build, alu, num_components);
 302 }
 303
 304 /**
 305  * Similar to nir_ssa_for_src(), but for alu src's, respecting the
 306  * nir_alu_src's swizzle.
 307  */
 308 static inline nir_ssa_def *
 309 nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr *instr, unsigned srcn)
 310 {
 311    static uint8_t trivial_swizzle[4] = { 0, 1, 2, 3 };
 312    nir_alu_src *src = &instr->src[srcn];
 313    unsigned num_components = nir_ssa_alu_instr_src_components(instr, srcn);
 314
 315    if (src->src.is_ssa && (src->src.ssa->num_components == num_components) &&
 316        !src->abs && !src->negate &&
 317        (memcmp(src->swizzle, trivial_swizzle, num_components) == 0))
 318       return src->src.ssa;
 319
 320    return nir_imov_alu(build, *src, num_components);
 321 }
 322
 323 static inline nir_ssa_def *
 324 nir_load_var(nir_builder *build, nir_variable *var)
 325 {
 326    const unsigned num_components = glsl_get_vector_elements(var->type);
 327
 328    nir_intrinsic_instr *load =
 329       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_var);
 330    load->num_components = num_components;
 331    load->variables[0] = nir_deref_var_create(load, var);
 332    nir_ssa_dest_init(&load->instr, &load->dest, num_components, NULL);
 333    nir_builder_instr_insert(build, &load->instr);
 334    return &load->dest.ssa;
 335 }
 336
 337 static inline void
 338 nir_store_var(nir_builder *build, nir_variable *var, nir_ssa_def *value,
 339               unsigned writemask)
 340 {
 341    const unsigned num_components = glsl_get_vector_elements(var->type);
 342
 343    nir_intrinsic_instr *store =
 344       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_var);
 345    store->num_components = num_components;
 346    nir_intrinsic_set_write_mask(store, writemask);
 347    store->variables[0] = nir_deref_var_create(store, var);
 348    store->src[0] = nir_src_for_ssa(value);
 349    nir_builder_instr_insert(build, &store->instr);
 350 }
 351
 352 static inline nir_ssa_def *
 353 nir_load_system_value(nir_builder *build, nir_intrinsic_op op, int index)
 354 {
 355    nir_intrinsic_instr *load = nir_intrinsic_instr_create(build->shader, op);
 356    load->num_components = nir_intrinsic_infos[op].dest_components;
 357    load->const_index[0] = index;
 358    nir_ssa_dest_init(&load->instr, &load->dest,
 359                      nir_intrinsic_infos[op].dest_components, NULL);
 360    nir_builder_instr_insert(build, &load->instr);
 361    return &load->dest.ssa;
 362 }
 363
 364 #endif /* NIR_BUILDER_H */