src/broadcom/compiler/v3d_nir_lower_io.c

   1 /*
   2  * Copyright © 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 #include "compiler/v3d_compiler.h"
  25 #include "compiler/nir/nir_builder.h"
  26
  27 /**
  28  * Walks the NIR generated by TGSI-to-NIR or GLSL-to-NIR to lower its io
  29  * intrinsics into something amenable to the V3D architecture.
  30  *
  31  * After moving more and more logic to NIR, all that's left here is fixing up
  32  * addressing on uniform loads.  FS input and VS output scalarization is
  33  * handled by nir_lower_io_to_scalar().
  34  */
  35
  36 /* Convert the uniform offset to bytes.  If it happens to be a constant,
  37  * constant-folding will clean up the shift for us.
  38  */
  39 static void
  40 v3d_nir_lower_uniform(struct v3d_compile *c, nir_builder *b,
  41                       nir_intrinsic_instr *intr)
  42 {
  43         b->cursor = nir_before_instr(&intr->instr);
  44
  45         nir_intrinsic_set_base(intr, nir_intrinsic_base(intr) * 16);
  46
  47         nir_instr_rewrite_src(&intr->instr,
  48                               &intr->src[0],
  49                               nir_src_for_ssa(nir_ishl(b, intr->src[0].ssa,
  50                                                        nir_imm_int(b, 4))));
  51 }
  52
  53 static void
  54 v3d_nir_lower_io_instr(struct v3d_compile *c, nir_builder *b,
  55                        struct nir_instr *instr)
  56 {
  57         if (instr->type != nir_instr_type_intrinsic)
  58                 return;
  59         nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
  60
  61         switch (intr->intrinsic) {
  62         case nir_intrinsic_load_uniform:
  63                 v3d_nir_lower_uniform(c, b, intr);
  64                 break;
  65
  66         default:
  67                 break;
  68         }
  69 }
  70
  71 static bool
  72 v3d_nir_lower_io_impl(struct v3d_compile *c, nir_function_impl *impl)
  73 {
  74         nir_builder b;
  75         nir_builder_init(&b, impl);
  76
  77         nir_foreach_block(block, impl) {
  78                 nir_foreach_instr_safe(instr, block)
  79                         v3d_nir_lower_io_instr(c, &b, instr);
  80         }
  81
  82         nir_metadata_preserve(impl, nir_metadata_block_index |
  83                               nir_metadata_dominance);
  84
  85         return true;
  86 }
  87
  88 void
  89 v3d_nir_lower_io(nir_shader *s, struct v3d_compile *c)
  90 {
  91         nir_foreach_function(function, s) {
  92                 if (function->impl)
  93                         v3d_nir_lower_io_impl(c, function->impl);
  94         }
  95 }