src/gallium/auxiliary/tgsi/tgsi_emulate.c

   1 /*
   2  * Copyright (C) 2015 Advanced Micro Devices, Inc.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  *
  24  */
  25
  26 #include "tgsi/tgsi_transform.h"
  27 #include "tgsi/tgsi_scan.h"
  28 #include "tgsi/tgsi_dump.h"
  29 #include "util/u_debug.h"
  30
  31 #include "tgsi_emulate.h"
  32
  33 struct tgsi_emulation_context {
  34    struct tgsi_transform_context base;
  35    struct tgsi_shader_info info;
  36    unsigned flags;
  37    bool first_instruction_emitted;
  38 };
  39
  40 static inline struct tgsi_emulation_context *
  41 tgsi_emulation_context(struct tgsi_transform_context *tctx)
  42 {
  43    return (struct tgsi_emulation_context *)tctx;
  44 }
  45
  46 static void
  47 transform_decl(struct tgsi_transform_context *tctx,
  48                struct tgsi_full_declaration *decl)
  49 {
  50    struct tgsi_emulation_context *ctx = tgsi_emulation_context(tctx);
  51
  52    if (ctx->flags & TGSI_EMU_FORCE_PERSAMPLE_INTERP &&
  53        decl->Declaration.File == TGSI_FILE_INPUT) {
  54       assert(decl->Declaration.Interpolate);
  55       decl->Interp.Location = TGSI_INTERPOLATE_LOC_SAMPLE;
  56    }
  57
  58    tctx->emit_declaration(tctx, decl);
  59 }
  60
  61 static void
  62 passthrough_edgeflag(struct tgsi_transform_context *tctx)
  63 {
  64    struct tgsi_emulation_context *ctx = tgsi_emulation_context(tctx);
  65    struct tgsi_full_declaration decl;
  66    struct tgsi_full_instruction new_inst;
  67
  68    /* Input */
  69    decl = tgsi_default_full_declaration();
  70    decl.Declaration.File = TGSI_FILE_INPUT;
  71    decl.Range.First = decl.Range.Last = ctx->info.num_inputs;
  72    tctx->emit_declaration(tctx, &decl);
  73
  74    /* Output */
  75    decl = tgsi_default_full_declaration();
  76    decl.Declaration.File = TGSI_FILE_OUTPUT;
  77    decl.Declaration.Semantic = true;
  78    decl.Range.First = decl.Range.Last = ctx->info.num_outputs;
  79    decl.Semantic.Name = TGSI_SEMANTIC_EDGEFLAG;
  80    decl.Semantic.Index = 0;
  81    tctx->emit_declaration(tctx, &decl);
  82
  83    /* MOV */
  84    new_inst = tgsi_default_full_instruction();
  85    new_inst.Instruction.Opcode = TGSI_OPCODE_MOV;
  86
  87    new_inst.Instruction.NumDstRegs = 1;
  88    new_inst.Dst[0].Register.File  = TGSI_FILE_OUTPUT;
  89    new_inst.Dst[0].Register.Index = ctx->info.num_outputs;
  90    new_inst.Dst[0].Register.WriteMask = TGSI_WRITEMASK_XYZW;
  91
  92    new_inst.Instruction.NumSrcRegs = 1;
  93    new_inst.Src[0].Register.File  = TGSI_FILE_INPUT;
  94    new_inst.Src[0].Register.Index = ctx->info.num_inputs;
  95    new_inst.Src[0].Register.SwizzleX = TGSI_SWIZZLE_X;
  96    new_inst.Src[0].Register.SwizzleY = TGSI_SWIZZLE_X;
  97    new_inst.Src[0].Register.SwizzleZ = TGSI_SWIZZLE_X;
  98    new_inst.Src[0].Register.SwizzleW = TGSI_SWIZZLE_X;
  99
 100    tctx->emit_instruction(tctx, &new_inst);
 101 }
 102
 103 static void
 104 transform_instr(struct tgsi_transform_context *tctx,
 105                 struct tgsi_full_instruction *inst)
 106 {
 107    struct tgsi_emulation_context *ctx = tgsi_emulation_context(tctx);
 108
 109    /* Pass through edgeflags. */
 110    if (!ctx->first_instruction_emitted) {
 111       ctx->first_instruction_emitted = true;
 112
 113       if (ctx->flags & TGSI_EMU_PASSTHROUGH_EDGEFLAG)
 114          passthrough_edgeflag(tctx);
 115    }
 116
 117    /* Clamp color outputs. */
 118    if (ctx->flags & TGSI_EMU_CLAMP_COLOR_OUTPUTS) {
 119       int i;
 120       for (i = 0; i < inst->Instruction.NumDstRegs; i++) {
 121          unsigned semantic;
 122
 123          if (inst->Dst[i].Register.File != TGSI_FILE_OUTPUT ||
 124              inst->Dst[i].Register.Indirect)
 125             continue;
 126
 127          semantic =
 128             ctx->info.output_semantic_name[inst->Dst[i].Register.Index];
 129
 130          if (semantic == TGSI_SEMANTIC_COLOR ||
 131              semantic == TGSI_SEMANTIC_BCOLOR)
 132             inst->Instruction.Saturate = true;
 133       }
 134    }
 135
 136    tctx->emit_instruction(tctx, inst);
 137 }
 138
 139 const struct tgsi_token *
 140 tgsi_emulate(const struct tgsi_token *tokens, unsigned flags)
 141 {
 142    struct tgsi_emulation_context ctx;
 143    struct tgsi_token *newtoks;
 144    int newlen;
 145
 146    if (!(flags & (TGSI_EMU_CLAMP_COLOR_OUTPUTS |
 147                   TGSI_EMU_PASSTHROUGH_EDGEFLAG |
 148                   TGSI_EMU_FORCE_PERSAMPLE_INTERP)))
 149       return NULL;
 150
 151    memset(&ctx, 0, sizeof(ctx));
 152    ctx.flags = flags;
 153    tgsi_scan_shader(tokens, &ctx.info);
 154
 155    if (flags & TGSI_EMU_FORCE_PERSAMPLE_INTERP)
 156       ctx.base.transform_declaration = transform_decl;
 157
 158    if (flags & (TGSI_EMU_CLAMP_COLOR_OUTPUTS |
 159                 TGSI_EMU_PASSTHROUGH_EDGEFLAG))
 160       ctx.base.transform_instruction = transform_instr;
 161
 162    newlen = tgsi_num_tokens(tokens) + 20;
 163    newtoks = tgsi_alloc_tokens(newlen);
 164    if (!newtoks)
 165       return NULL;
 166
 167    tgsi_transform_shader(tokens, newtoks, newlen, &ctx.base);
 168    return newtoks;
 169 }