src/vulkan/anv_nir_lower_push_constants.c

   1 /*
   2  * Copyright © 2015 Intel Corporation
   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 "anv_nir.h"
  25
  26 struct lower_push_constants_state {
  27    nir_shader *shader;
  28    bool is_scalar;
  29 };
  30
  31 static bool
  32 lower_push_constants_block(nir_block *block, void *void_state)
  33 {
  34    struct lower_push_constants_state *state = void_state;
  35
  36    nir_foreach_instr(block, instr) {
  37       if (instr->type != nir_instr_type_intrinsic)
  38          continue;
  39
  40       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
  41
  42       /* TODO: Handle indirect push constants */
  43       if (intrin->intrinsic != nir_intrinsic_load_push_constant)
  44          continue;
  45
  46       assert(intrin->const_index[0] % 4 == 0);
  47       unsigned dword_offset = intrin->const_index[0] / 4;
  48
  49       /* We just turn them into uniform loads with the appropreate offset */
  50       intrin->intrinsic = nir_intrinsic_load_uniform;
  51       intrin->const_index[0] = 0;
  52       if (state->is_scalar) {
  53          intrin->const_index[1] = dword_offset;
  54       } else {
  55          unsigned shift = dword_offset % 4;
  56          /* Can't cross the vec4 boundary */
  57          assert(shift + intrin->num_components <= 4);
  58
  59          /* vec4 shifts are in units of vec4's */
  60          intrin->const_index[1] = dword_offset / 4;
  61
  62          if (shift) {
  63             /* If there's a non-zero shift then we need to load a whole vec4
  64              * and use a move to swizzle it into place.
  65              */
  66             assert(intrin->dest.is_ssa);
  67             nir_alu_instr *mov = nir_alu_instr_create(state->shader,
  68                                                       nir_op_imov);
  69             mov->src[0].src = nir_src_for_ssa(&intrin->dest.ssa);
  70             for (unsigned i = 0; i < intrin->num_components; i++)
  71                mov->src[0].swizzle[i] = i + shift;
  72             mov->dest.write_mask = (1 << intrin->num_components) - 1;
  73             nir_ssa_dest_init(&mov->instr, &mov->dest.dest,
  74                               intrin->num_components, NULL);
  75
  76             nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
  77                                      nir_src_for_ssa(&mov->dest.dest.ssa));
  78             nir_instr_insert_after(&intrin->instr, &mov->instr);
  79
  80             /* Stomp the number of components to 4 */
  81             intrin->num_components = 4;
  82             intrin->dest.ssa.num_components = 4;
  83          }
  84       }
  85    }
  86
  87    return true;
  88 }
  89
  90 void
  91 anv_nir_lower_push_constants(nir_shader *shader, bool is_scalar)
  92 {
  93    struct lower_push_constants_state state = {
  94       .shader = shader,
  95       .is_scalar = is_scalar,
  96    };
  97
  98    nir_foreach_overload(shader, overload) {
  99       if (overload->impl)
 100          nir_foreach_block(overload->impl, lower_push_constants_block, &state);
 101    }
 102
 103    assert(shader->num_uniforms % 4 == 0);
 104    if (is_scalar)
 105       shader->num_uniforms /= 4;
 106    else
 107       shader->num_uniforms = DIV_ROUND_UP(shader->num_uniforms, 16);
 108 }