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