src/compiler/nir/nir_builtin_builder.c

   1 /*
   2  * Copyright © 2018 Red Hat Inc.
   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 #include "nir.h"
  25 #include "nir_builtin_builder.h"
  26
  27 nir_ssa_def*
  28 nir_cross(nir_builder *b, nir_ssa_def *x, nir_ssa_def *y)
  29 {
  30    unsigned yzx[3] = { 1, 2, 0 };
  31    unsigned zxy[3] = { 2, 0, 1 };
  32
  33    return nir_fsub(b, nir_fmul(b, nir_swizzle(b, x, yzx, 3, true),
  34                                   nir_swizzle(b, y, zxy, 3, true)),
  35                       nir_fmul(b, nir_swizzle(b, x, zxy, 3, true),
  36                                   nir_swizzle(b, y, yzx, 3, true)));
  37 }
  38
  39 nir_ssa_def*
  40 nir_fast_length(nir_builder *b, nir_ssa_def *vec)
  41 {
  42    switch (vec->num_components) {
  43    case 1: return nir_fsqrt(b, nir_fmul(b, vec, vec));
  44    case 2: return nir_fsqrt(b, nir_fdot2(b, vec, vec));
  45    case 3: return nir_fsqrt(b, nir_fdot3(b, vec, vec));
  46    case 4: return nir_fsqrt(b, nir_fdot4(b, vec, vec));
  47    default:
  48       unreachable("Invalid number of components");
  49    }
  50 }
  51
  52 nir_ssa_def*
  53 nir_smoothstep(nir_builder *b, nir_ssa_def *edge0, nir_ssa_def *edge1, nir_ssa_def *x)
  54 {
  55    nir_ssa_def *f2 = nir_imm_floatN_t(b, 2.0, x->bit_size);
  56    nir_ssa_def *f3 = nir_imm_floatN_t(b, 3.0, x->bit_size);
  57
  58    /* t = clamp((x - edge0) / (edge1 - edge0), 0, 1) */
  59    nir_ssa_def *t =
  60       nir_fsat(b, nir_fdiv(b, nir_fsub(b, x, edge0),
  61                               nir_fsub(b, edge1, edge0)));
  62
  63    /* result = t * t * (3 - 2 * t) */
  64    return nir_fmul(b, t, nir_fmul(b, t, nir_fsub(b, f3, nir_fmul(b, f2, t))));
  65 }