src/glsl/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 struct exec_list;
  28
  29 typedef struct nir_builder {
  30    struct exec_list *cf_node_list;
  31    nir_instr *before_instr;
  32    nir_instr *after_instr;
  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->overload->function->shader;
  44 }
  45
  46 static inline void
  47 nir_builder_insert_after_cf_list(nir_builder *build,
  48                                  struct exec_list *cf_node_list)
  49 {
  50    build->cf_node_list = cf_node_list;
  51    build->before_instr = NULL;
  52    build->after_instr = NULL;
  53 }
  54
  55 static inline void
  56 nir_builder_insert_before_instr(nir_builder *build, nir_instr *before_instr)
  57 {
  58    build->cf_node_list = NULL;
  59    build->before_instr = before_instr;
  60    build->after_instr = NULL;
  61 }
  62
  63 static inline void
  64 nir_builder_insert_after_instr(nir_builder *build, nir_instr *after_instr)
  65 {
  66    build->cf_node_list = NULL;
  67    build->before_instr = NULL;
  68    build->after_instr = after_instr;
  69 }
  70
  71 static inline void
  72 nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
  73 {
  74    if (build->cf_node_list) {
  75       nir_instr_insert_after_cf_list(build->cf_node_list, instr);
  76    } else if (build->before_instr) {
  77       nir_instr_insert_before(build->before_instr, instr);
  78    } else {
  79       assert(build->after_instr);
  80       nir_instr_insert_after(build->after_instr, instr);
  81       build->after_instr = instr;
  82    }
  83 }
  84
  85 static inline nir_ssa_def *
  86 nir_build_imm(nir_builder *build, unsigned num_components, nir_const_value value)
  87 {
  88    nir_load_const_instr *load_const =
  89       nir_load_const_instr_create(build->shader, num_components);
  90    if (!load_const)
  91       return NULL;
  92
  93    load_const->value = value;
  94
  95    nir_builder_instr_insert(build, &load_const->instr);
  96
  97    return &load_const->def;
  98 }
  99
 100 static inline nir_ssa_def *
 101 nir_imm_float(nir_builder *build, float x)
 102 {
 103    nir_const_value v = { { .f = {x, 0, 0, 0} } };
 104    return nir_build_imm(build, 1, v);
 105 }
 106
 107 static inline nir_ssa_def *
 108 nir_imm_vec4(nir_builder *build, float x, float y, float z, float w)
 109 {
 110    nir_const_value v = { { .f = {x, y, z, w} } };
 111    return nir_build_imm(build, 4, v);
 112 }
 113
 114 static inline nir_ssa_def *
 115 nir_imm_int(nir_builder *build, int x)
 116 {
 117    nir_const_value v = { { .i = {x, 0, 0, 0} } };
 118    return nir_build_imm(build, 1, v);
 119 }
 120
 121 static inline nir_ssa_def *
 122 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
 123               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
 124 {
 125    const nir_op_info *op_info = &nir_op_infos[op];
 126    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
 127    if (!instr)
 128       return NULL;
 129
 130    instr->src[0].src = nir_src_for_ssa(src0);
 131    if (src1)
 132       instr->src[1].src = nir_src_for_ssa(src1);
 133    if (src2)
 134       instr->src[2].src = nir_src_for_ssa(src2);
 135    if (src3)
 136       instr->src[3].src = nir_src_for_ssa(src3);
 137
 138    /* Guess the number of components the destination temporary should have
 139     * based on our input sizes, if it's not fixed for the op.
 140     */
 141    unsigned num_components = op_info->output_size;
 142    if (num_components == 0) {
 143       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 144          if (op_info->input_sizes[i] == 0)
 145             num_components = MAX2(num_components,
 146                                   instr->src[i].src.ssa->num_components);
 147       }
 148    }
 149    assert(num_components != 0);
 150
 151    /* Make sure we don't swizzle from outside of our source vector (like if a
 152     * scalar value was passed into a multiply with a vector).
 153     */
 154    for (unsigned i = 0; i < op_info->num_inputs; i++) {
 155       for (unsigned j = instr->src[i].src.ssa->num_components; j < 4; j++) {
 156          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
 157       }
 158    }
 159
 160    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components, NULL);
 161    instr->dest.write_mask = (1 << num_components) - 1;
 162
 163    nir_builder_instr_insert(build, &instr->instr);
 164
 165    return &instr->dest.dest.ssa;
 166 }
 167
 168 #define ALU1(op)                                                          \
 169 static inline nir_ssa_def *                                               \
 170 nir_##op(nir_builder *build, nir_ssa_def *src0)                           \
 171 {                                                                         \
 172    return nir_build_alu(build, nir_op_##op, src0, NULL, NULL, NULL);      \
 173 }
 174
 175 #define ALU2(op)                                                          \
 176 static inline nir_ssa_def *                                               \
 177 nir_##op(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)        \
 178 {                                                                         \
 179    return nir_build_alu(build, nir_op_##op, src0, src1, NULL, NULL);      \
 180 }
 181
 182 #define ALU3(op)                                                          \
 183 static inline nir_ssa_def *                                               \
 184 nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 185          nir_ssa_def *src1, nir_ssa_def *src2)                            \
 186 {                                                                         \
 187    return nir_build_alu(build, nir_op_##op, src0, src1, src2, NULL);      \
 188 }
 189
 190 #define ALU4(op)                                                          \
 191 static inline nir_ssa_def *                                               \
 192 nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 193          nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)         \
 194 {                                                                         \
 195    return nir_build_alu(build, nir_op_##op, src0, src1, src2, src3);      \
 196 }
 197
 198 #include "nir_builder_opcodes.h"
 199
 200 /**
 201  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
 202  */
 203 static inline nir_ssa_def *
 204 nir_fmov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 205 {
 206    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_fmov);
 207    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components, NULL);
 208    mov->dest.write_mask = (1 << num_components) - 1;
 209    mov->src[0] = src;
 210    nir_builder_instr_insert(build, &mov->instr);
 211
 212    return &mov->dest.dest.ssa;
 213 }
 214
 215 static inline nir_ssa_def *
 216 nir_imov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 217 {
 218    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_imov);
 219    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components, NULL);
 220    mov->dest.write_mask = (1 << num_components) - 1;
 221    mov->src[0] = src;
 222    nir_builder_instr_insert(build, &mov->instr);
 223
 224    return &mov->dest.dest.ssa;
 225 }
 226
 227 /**
 228  * Construct an fmov or imov that reswizzles the source's components.
 229  */
 230 static inline nir_ssa_def *
 231 nir_swizzle(nir_builder *build, nir_ssa_def *src, unsigned swiz[4],
 232             unsigned num_components, bool use_fmov)
 233 {
 234    nir_alu_src alu_src = { NIR_SRC_INIT };
 235    alu_src.src = nir_src_for_ssa(src);
 236    for (int i = 0; i < 4; i++)
 237       alu_src.swizzle[i] = swiz[i];
 238
 239    return use_fmov ? nir_fmov_alu(build, alu_src, num_components) :
 240                      nir_imov_alu(build, alu_src, num_components);
 241 }
 242
 243 /* Selects the right fdot given the number of components in each source. */
 244 static inline nir_ssa_def *
 245 nir_fdot(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)
 246 {
 247    assert(src0->num_components == src1->num_components);
 248    switch (src0->num_components) {
 249    case 1: return nir_fmul(build, src0, src1);
 250    case 2: return nir_fdot2(build, src0, src1);
 251    case 3: return nir_fdot3(build, src0, src1);
 252    case 4: return nir_fdot4(build, src0, src1);
 253    default:
 254       unreachable("bad component size");
 255    }
 256
 257    return NULL;
 258 }
 259
 260 /**
 261  * Turns a nir_src into a nir_ssa_def * so it can be passed to
 262  * nir_build_alu()-based builder calls.
 263  */
 264 static inline nir_ssa_def *
 265 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
 266 {
 267    if (src.is_ssa && src.ssa->num_components == num_components)
 268       return src.ssa;
 269
 270    nir_alu_src alu = { NIR_SRC_INIT };
 271    alu.src = src;
 272    for (int j = 0; j < 4; j++)
 273       alu.swizzle[j] = j;
 274
 275    return nir_imov_alu(build, alu, num_components);
 276 }
 277
 278 #endif /* NIR_BUILDER_H */