1/*
2 * Copyright (C) 2020 Collabora, Ltd.
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 * Authors (Collabora):
24 *   Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
25 */
26
27/* Fuses f2f16 modifiers into loads */
28
29#include "compiler/nir/nir.h"
30#include "compiler/nir/nir_builder.h"
31#include "panfrost/util/pan_ir.h"
32
33bool nir_fuse_io_16(nir_shader *shader);
34
35static bool
36nir_src_is_f2fmp(nir_src *use)
37{
38   nir_instr *parent = use->parent_instr;
39
40   if (parent->type != nir_instr_type_alu)
41      return false;
42
43   nir_alu_instr *alu = nir_instr_as_alu(parent);
44   return (alu->op == nir_op_f2fmp);
45}
46
47bool
48nir_fuse_io_16(nir_shader *shader)
49{
50   bool progress = false;
51
52   nir_foreach_function(function, shader) {
53      if (!function->impl) continue;
54
55      nir_builder b;
56      nir_builder_init(&b, function->impl);
57
58      nir_foreach_block(block, function->impl) {
59         nir_foreach_instr_safe(instr, block) {
60            if (instr->type != nir_instr_type_intrinsic) continue;
61
62            nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
63
64            if (intr->intrinsic != nir_intrinsic_load_interpolated_input)
65                    continue;
66
67            if (nir_dest_bit_size(intr->dest) != 32)
68                    continue;
69
70            /* We swizzle at a 32-bit level so need a multiple of 2. We could
71             * do a bit better and handle even components though */
72            if (nir_intrinsic_component(intr))
73               continue;
74
75            if (!intr->dest.is_ssa)
76               continue;
77
78            if (!list_is_empty(&intr->dest.ssa.if_uses))
79               return false;
80
81            bool valid = true;
82
83            nir_foreach_use(src, &intr->dest.ssa)
84               valid &= nir_src_is_f2fmp(src);
85
86            if (!valid)
87               continue;
88
89            intr->dest.ssa.bit_size = 16;
90
91            nir_builder b;
92            nir_builder_init(&b, function->impl);
93            b.cursor = nir_after_instr(instr);
94
95            /* The f2f32(f2fmp(x)) will cancel by opt_algebraic */
96            nir_ssa_def *conv = nir_f2f32(&b, &intr->dest.ssa);
97            nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, conv,
98                                           conv->parent_instr);
99
100            progress |= true;
101         }
102      }
103
104      nir_metadata_preserve(function->impl, nir_metadata_block_index | nir_metadata_dominance);
105
106   }
107
108   return progress;
109}
110