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 * Currently, it splits VS inputs and uniforms into scalars, drops any 32 * non-position outputs in coordinate shaders, and fixes up the addressing on 33 * indirect uniform loads. FS input and VS output scalarization is handled by 34 * nir_lower_io_to_scalar(). 35 */ 36 37 static void 38 replace_intrinsic_with_vec(nir_builder *b, nir_intrinsic_instr *intr, 39 nir_ssa_def **comps) 40 { 41 42 /* Batch things back together into a vector. This will get split by 43 * the later ALU scalarization pass. 44 */ 45 nir_ssa_def *vec = nir_vec(b, comps, intr->num_components); 46 47 /* Replace the old intrinsic with a reference to our reconstructed 48 * vector. 49 */ 50 nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(vec)); 51 nir_instr_remove(&intr->instr); 52 } 53 54 static void 55 v3d_nir_lower_output(struct v3d_compile *c, nir_builder *b, 56 nir_intrinsic_instr *intr) 57 { 58 nir_variable *output_var = NULL; 59 nir_foreach_variable(var, &c->s->outputs) { 60 if (var->data.driver_location == nir_intrinsic_base(intr)) { 61 output_var = var; 62 break; 63 } 64 } 65 assert(output_var); 66 67 if (c->vs_key) { 68 int slot = output_var->data.location; 69 bool used = false; 70 71 switch (slot) { 72 case VARYING_SLOT_PSIZ: 73 case VARYING_SLOT_POS: 74 used = true; 75 break; 76 77 default: 78 for (int i = 0; i < c->vs_key->num_fs_inputs; i++) { 79 if (v3d_slot_get_slot(c->vs_key->fs_inputs[i]) == slot) { 80 used = true; 81 break; 82 } 83 } 84 break; 85 } 86 87 if (!used) 88 nir_instr_remove(&intr->instr); 89 } 90 } 91 92 static void 93 v3d_nir_lower_uniform(struct v3d_compile *c, nir_builder *b, 94 nir_intrinsic_instr *intr) 95 { 96 b->cursor = nir_before_instr(&intr->instr); 97 98 /* Generate scalar loads equivalent to the original vector. */ 99 nir_ssa_def *dests[4]; 100 for (unsigned i = 0; i < intr->num_components; i++) { 101 nir_intrinsic_instr *intr_comp = 102 nir_intrinsic_instr_create(c->s, intr->intrinsic); 103 intr_comp->num_components = 1; 104 nir_ssa_dest_init(&intr_comp->instr, &intr_comp->dest, 1, 32, NULL); 105 106 /* Convert the uniform offset to bytes. If it happens 107 * to be a constant, constant-folding will clean up 108 * the shift for us. 109 */ 110 nir_intrinsic_set_base(intr_comp, 111 nir_intrinsic_base(intr) * 16 + 112 i * 4); 113 114 intr_comp->src[0] = 115 nir_src_for_ssa(nir_ishl(b, intr->src[0].ssa, 116 nir_imm_int(b, 4))); 117 118 dests[i] = &intr_comp->dest.ssa; 119 120 nir_builder_instr_insert(b, &intr_comp->instr); 121 } 122 123 replace_intrinsic_with_vec(b, intr, dests); 124 } 125 126 static void 127 v3d_nir_lower_io_instr(struct v3d_compile *c, nir_builder *b, 128 struct nir_instr *instr) 129 { 130 if (instr->type != nir_instr_type_intrinsic) 131 return; 132 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); 133 134 switch (intr->intrinsic) { 135 case nir_intrinsic_load_input: 136 break; 137 138 case nir_intrinsic_store_output: 139 v3d_nir_lower_output(c, b, intr); 140 break; 141 142 case nir_intrinsic_load_uniform: 143 v3d_nir_lower_uniform(c, b, intr); 144 break; 145 146 case nir_intrinsic_load_user_clip_plane: 147 default: 148 break; 149 } 150 } 151 152 static bool 153 v3d_nir_lower_io_impl(struct v3d_compile *c, nir_function_impl *impl) 154 { 155 nir_builder b; 156 nir_builder_init(&b, impl); 157 158 nir_foreach_block(block, impl) { 159 nir_foreach_instr_safe(instr, block) 160 v3d_nir_lower_io_instr(c, &b, instr); 161 } 162 163 nir_metadata_preserve(impl, nir_metadata_block_index | 164 nir_metadata_dominance); 165 166 return true; 167 } 168 169 void 170 v3d_nir_lower_io(nir_shader *s, struct v3d_compile *c) 171 { 172 nir_foreach_function(function, s) { 173 if (function->impl) 174 v3d_nir_lower_io_impl(c, function->impl); 175 } 176 } 177
