gallivm: More detailed analysis of tgsi shaders.

To allow more optimizations, in particular for direct textures.

4 files changed, 559 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/Makefile b/src/gallium/auxiliary/Makefile
index 02af4d9280a..abd33f6eef1 100644
--- a/src/gallium/auxiliary/Makefile
+++ b/src/gallium/auxiliary/Makefile
@@ -176,6 +176,7 @@ GALLIVM_SOURCES = \
         gallivm/lp_bld_struct.c \
         gallivm/lp_bld_swizzle.c \
         gallivm/lp_bld_tgsi_aos.c \
+        gallivm/lp_bld_tgsi_info.c \
         gallivm/lp_bld_tgsi_soa.c \
         gallivm/lp_bld_type.c \
         draw/draw_llvm.c \
diff --git a/src/gallium/auxiliary/SConscript b/src/gallium/auxiliary/SConscript
index 48547c4b2c6..94cd74424a0 100644
--- a/src/gallium/auxiliary/SConscript
+++ b/src/gallium/auxiliary/SConscript
@@ -227,6 +227,7 @@ if env['llvm']:
     'gallivm/lp_bld_struct.c',
     'gallivm/lp_bld_swizzle.c',
     'gallivm/lp_bld_tgsi_aos.c',
+    'gallivm/lp_bld_tgsi_info.c',
     'gallivm/lp_bld_tgsi_soa.c',
     'gallivm/lp_bld_type.c',
     'draw/draw_llvm.c',
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
index 97318b3456c..0173bc4a7fc 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
@@ -36,6 +36,9 @@
 #define LP_BLD_TGSI_H
 
 #include "gallivm/lp_bld.h"
+#include "pipe/p_compiler.h"
+#include "pipe/p_state.h"
+#include "tgsi/tgsi_scan.h"
 
 
 struct tgsi_token;
@@ -55,6 +58,75 @@ enum lp_build_tex_modifier {
 
 
 /**
+ * Describe a channel of a register.
+ *
+ * The value can be a:
+ * - immediate value (i.e. derived from a IMM register)
+ * - CONST[n].x/y/z/w
+ * - IN[n].x/y/z/w
+ * - undetermined (when .file == TGSI_FILE_NULL)
+ *
+ * This is one of the analysis results, and is used to described
+ * the output color in terms of inputs.
+ */
+struct lp_tgsi_channel_info
+{
+   unsigned file:4; /* TGSI_FILE_* */
+   unsigned swizzle:3; /* PIPE_SWIZZLE_x */
+   union {
+      uint32_t index;
+      float value; /* for TGSI_FILE_IMMEDIATE */
+   };
+};
+
+
+/**
+ * Describe a texture sampler interpolator.
+ *
+ * The interpolation is described in terms of regular inputs.
+ */
+struct lp_tgsi_texture_info
+{
+   struct lp_tgsi_channel_info coord[4];
+   unsigned target:8; /* TGSI_TEXTURE_* */
+   unsigned unit:8;  /* Sampler unit */
+   unsigned modifier:8; /* LP_BLD_TEX_MODIFIER_* */
+};
+
+
+struct lp_tgsi_info
+{
+   struct tgsi_shader_info base;
+
+   /*
+    * Whether any of the texture opcodes access a register file other than
+    * TGSI_FILE_INPUT.
+    *
+    * We could also handle TGSI_FILE_CONST/IMMEDIATE here, but there is little
+    * benefit.
+    */
+   unsigned indirect_textures:1;
+
+   /*
+    * Texture opcode description. Aimed at detecting and described direct
+    * texture opcodes.
+    */
+   unsigned num_texs;
+   struct lp_tgsi_texture_info tex[PIPE_MAX_SAMPLERS];
+
+   /*
+    * Output description. Aimed at detecting and describing simple blit
+    * shaders.
+    */
+   struct lp_tgsi_channel_info output[PIPE_MAX_SHADER_OUTPUTS][4];
+
+   /*
+    * Shortcut pointers into the above (for fragment shaders).
+    */
+   const struct lp_tgsi_channel_info *cbuf[PIPE_MAX_COLOR_BUFS];
+};
+
+/**
  * Sampler code generation interface.
  *
  * Although texture sampling is a requirement for TGSI translation, it is
@@ -97,6 +169,11 @@ struct lp_build_sampler_aos
 
 
 void
+lp_build_tgsi_info(const struct tgsi_token *tokens,
+                   struct lp_tgsi_info *info);
+
+
+void
 lp_build_tgsi_soa(LLVMBuilderRef builder,
                   const struct tgsi_token *tokens,
                   struct lp_type type,
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_info.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_info.c
new file mode 100644
index 00000000000..eab72b8eb7d
--- /dev/null
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_info.c
@@ -0,0 +1,480 @@
+/**************************************************************************
+ *
+ * Copyright 2010 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ **************************************************************************/
+
+
+#include "util/u_memory.h"
+#include "util/u_math.h"
+#include "tgsi/tgsi_parse.h"
+#include "tgsi/tgsi_text.h"
+#include "tgsi/tgsi_util.h"
+#include "tgsi/tgsi_dump.h"
+#include "lp_bld_debug.h"
+#include "lp_bld_tgsi.h"
+
+
+/**
+ * Analysis context.
+ *
+ * This is where we keep store the value of each channel of the IMM/TEMP/OUT
+ * register values, as we walk the shader.
+ */
+struct analysis_context
+{
+   struct lp_tgsi_info *info;
+
+   unsigned num_imms;
+   float imm[32][4];
+
+   struct lp_tgsi_channel_info temp[32][4];
+};
+
+
+/**
+ * Describe the specified channel of the src register.
+ */
+static void
+analyse_src(struct analysis_context *ctx,
+            struct lp_tgsi_channel_info *chan_info,
+            const struct tgsi_src_register *src,
+            unsigned chan)
+{
+   chan_info->file = TGSI_FILE_NULL;
+   if (!src->Indirect && !src->Absolute && !src->Negate) {
+      unsigned swizzle = tgsi_util_get_src_register_swizzle(src, chan);
+      if (src->File == TGSI_FILE_TEMPORARY) {
+         if (src->Index < Elements(ctx->temp)) {
+            *chan_info = ctx->temp[src->Index][swizzle];
+         }
+      } else {
+         chan_info->file = src->File;
+         if (src->File == TGSI_FILE_IMMEDIATE) {
+            assert(src->Index < Elements(ctx->imm));
+            if (src->Index < Elements(ctx->imm)) {
+               chan_info->value = ctx->imm[src->Index][swizzle];
+            }
+         } else {
+            chan_info->index = src->Index;
+            chan_info->swizzle = swizzle;
+         }
+      }
+   }
+}
+
+
+/**
+ * Whether this register channel refers to a specific immediate value.
+ */
+static boolean
+is_immediate(const struct lp_tgsi_channel_info *chan_info, float value)
+{
+   return chan_info->file == TGSI_FILE_IMMEDIATE &&
+          chan_info->value == value;
+}
+
+
+static void
+analyse_tex(struct analysis_context *ctx,
+            const struct tgsi_full_instruction *inst,
+            enum lp_build_tex_modifier modifier)
+{
+   struct lp_tgsi_info *info = ctx->info;
+   unsigned chan;
+
+   if (info->num_texs < Elements(info->tex)) {
+      struct lp_tgsi_texture_info *tex_info = &info->tex[info->num_texs];
+      bool indirect = FALSE;
+      unsigned readmask = 0;
+
+      tex_info->target = inst->Texture.Texture;
+      switch (inst->Texture.Texture) {
+      case TGSI_TEXTURE_1D:
+         readmask = TGSI_WRITEMASK_X;
+         break;
+      case TGSI_TEXTURE_2D:
+      case TGSI_TEXTURE_RECT:
+         readmask = TGSI_WRITEMASK_XY;
+         break;
+      case TGSI_TEXTURE_SHADOW1D:
+      case TGSI_TEXTURE_SHADOW2D:
+      case TGSI_TEXTURE_SHADOWRECT:
+      case TGSI_TEXTURE_3D:
+      case TGSI_TEXTURE_CUBE:
+         readmask = TGSI_WRITEMASK_XYZ;
+         break;
+      default:
+         assert(0);
+         return;
+      }
+
+      if (modifier == LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV) {
+         /* We don't track explicit derivatives, although we could */
+         indirect = TRUE;
+         tex_info->unit = inst->Src[3].Register.Index;
+      }  else {
+         if (modifier == LP_BLD_TEX_MODIFIER_PROJECTED ||
+             modifier == LP_BLD_TEX_MODIFIER_LOD_BIAS ||
+             modifier == LP_BLD_TEX_MODIFIER_EXPLICIT_LOD) {
+            readmask |= TGSI_WRITEMASK_W;
+         }
+         tex_info->unit = inst->Src[1].Register.Index;
+      }
+
+      for (chan = 0; chan < 4; ++chan) {
+         struct lp_tgsi_channel_info *chan_info = &tex_info->coord[chan];
+         if (readmask & (1 << chan)) {
+            analyse_src(ctx, chan_info, &inst->Src[0].Register, chan);
+            if (chan_info->file != TGSI_FILE_INPUT) {
+               indirect = TRUE;
+            }
+         } else {
+            memset(chan_info, 0, sizeof *chan_info);
+         }
+      }
+
+      if (indirect) {
+         info->indirect_textures = TRUE;
+      }
+
+      ++info->num_texs;
+   } else {
+      info->indirect_textures = TRUE;
+   }
+}
+
+
+/**
+ * Process an instruction, and update the register values accordingly.
+ */
+static void
+analyse_instruction(struct analysis_context *ctx,
+                    struct tgsi_full_instruction *inst)
+{
+   struct lp_tgsi_info *info = ctx->info;
+   struct lp_tgsi_channel_info (*regs)[4];
+   unsigned max_regs;
+   unsigned i;
+   unsigned index;
+   unsigned chan;
+
+   for (i = 0; i < inst->Instruction.NumDstRegs; ++i) {
+      const struct tgsi_dst_register *dst = &inst->Dst[i].Register;
+
+      /*
+       * Get the lp_tgsi_channel_info array corresponding to the destination
+       * register file.
+       */
+
+      if (dst->File == TGSI_FILE_TEMPORARY) {
+         regs = ctx->temp;
+         max_regs = Elements(ctx->temp);
+      } else if (dst->File == TGSI_FILE_OUTPUT) {
+         regs = info->output;
+         max_regs = Elements(info->output);
+      } else if (dst->File == TGSI_FILE_ADDRESS ||
+                 dst->File == TGSI_FILE_PREDICATE) {
+         continue;
+      } else {
+         assert(0);
+         continue;
+      }
+
+      /*
+       * Detect direct TEX instructions
+       */
+
+      switch (inst->Instruction.Opcode) {
+      case TGSI_OPCODE_TEX:
+         analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_NONE);
+         break;
+      case TGSI_OPCODE_TXD:
+         analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV);
+         break;
+      case TGSI_OPCODE_TXB:
+         analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_LOD_BIAS);
+         break;
+      case TGSI_OPCODE_TXL:
+         analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_EXPLICIT_LOD);
+         break;
+      case TGSI_OPCODE_TXP:
+         analyse_tex(ctx, inst, LP_BLD_TEX_MODIFIER_PROJECTED);
+         break;
+      default:
+         break;
+      }
+
+      /*
+       * Keep track of assignments and writes
+       */
+
+      if (dst->Indirect) {
+         /*
+          * It could be any register index so clear all register indices.
+          */
+
+         for (chan = 0; chan < 4; ++chan) {
+            if (dst->WriteMask & (1 << chan)) {
+               for (index = 0; index < max_regs; ++index) {
+                  regs[index][chan].file = TGSI_FILE_NULL;
+               }
+            }
+         }
+      } else if (dst->Index < max_regs) {
+         /*
+          * Update this destination register value.
+          */
+
+         struct lp_tgsi_channel_info res[4];
+
+         memset(res, 0, sizeof res);
+
+         if (!inst->Instruction.Predicate &&
+             !inst->Instruction.Saturate) {
+            for (chan = 0; chan < 4; ++chan) {
+               if (dst->WriteMask & (1 << chan)) {
+                  if (inst->Instruction.Opcode == TGSI_OPCODE_MOV) {
+                     analyse_src(ctx, &res[chan],
+                                 &inst->Src[0].Register, chan);
+                  } else if (inst->Instruction.Opcode == TGSI_OPCODE_MUL) {
+                     /*
+                      * Propagate values across 1.0 and 0.0 multiplications.
+                      */
+
+                     struct lp_tgsi_channel_info src0;
+                     struct lp_tgsi_channel_info src1;
+
+                     analyse_src(ctx, &src0, &inst->Src[0].Register, chan);
+                     analyse_src(ctx, &src1, &inst->Src[1].Register, chan);
+
+                     if (is_immediate(&src0, 0.0f)) {
+                        res[chan] = src0;
+                     } else if (is_immediate(&src1, 0.0f)) {
+                        res[chan] = src1;
+                     } else if (is_immediate(&src0, 1.0f)) {
+                        res[chan] = src1;
+                     } else if (is_immediate(&src1, 1.0f)) {
+                        res[chan] = src0;
+                     }
+                  }
+               }
+            }
+         }
+
+         for (chan = 0; chan < 4; ++chan) {
+            if (dst->WriteMask & (1 << chan)) {
+               regs[dst->Index][chan] = res[chan];
+            }
+         }
+      }
+   }
+
+   /*
+    * Clear all temporaries information in presence of a control flow opcode.
+    */
+
+   switch (inst->Instruction.Opcode) {
+   case TGSI_OPCODE_IF:
+   case TGSI_OPCODE_IFC:
+   case TGSI_OPCODE_ELSE:
+   case TGSI_OPCODE_ENDIF:
+   case TGSI_OPCODE_BGNLOOP:
+   case TGSI_OPCODE_BRK:
+   case TGSI_OPCODE_BREAKC:
+   case TGSI_OPCODE_CONT:
+   case TGSI_OPCODE_ENDLOOP:
+   case TGSI_OPCODE_CALLNZ:
+   case TGSI_OPCODE_CAL:
+   case TGSI_OPCODE_BGNSUB:
+   case TGSI_OPCODE_ENDSUB:
+   case TGSI_OPCODE_SWITCH:
+   case TGSI_OPCODE_CASE:
+   case TGSI_OPCODE_DEFAULT:
+   case TGSI_OPCODE_ENDSWITCH:
+   case TGSI_OPCODE_RET:
+   case TGSI_OPCODE_END:
+      /* XXX: Are there more cases? */
+      memset(&ctx->temp, 0, sizeof ctx->temp);
+      memset(&info->output, 0, sizeof info->output);
+   default:
+      break;
+   }
+}
+
+
+static INLINE void
+dump_info(const struct tgsi_token *tokens,
+          struct lp_tgsi_info *info)
+{
+   unsigned index;
+   unsigned chan;
+
+   tgsi_dump(tokens, 0);
+
+   for (index = 0; index < info->num_texs; ++index) {
+      const struct lp_tgsi_texture_info *tex_info = &info->tex[index];
+      debug_printf("TEX[%u] =", index);
+      for (chan = 0; chan < 4; ++chan) {
+         const struct lp_tgsi_channel_info *chan_info =
+               &tex_info->coord[chan];
+         if (chan_info->file != TGSI_FILE_NULL) {
+            debug_printf(" %s[%u].%c",
+                         tgsi_file_names[chan_info->file],
+                         chan_info->index,
+                         "xyzw01"[chan_info->swizzle]);
+         } else {
+            debug_printf(" _");
+         }
+      }
+      debug_printf(", SAMP[%u], %s\n",
+                   tex_info->unit,
+                   tgsi_texture_names[tex_info->target]);
+   }
+
+   for (index = 0; index < PIPE_MAX_SHADER_OUTPUTS; ++index) {
+      for (chan = 0; chan < 4; ++chan) {
+         const struct lp_tgsi_channel_info *chan_info =
+               &info->output[index][chan];
+         if (chan_info->file != TGSI_FILE_NULL) {
+            debug_printf("OUT[%u].%c = ", index, "xyzw"[chan]);
+            if (chan_info->file == TGSI_FILE_IMMEDIATE) {
+               debug_printf("%f", chan_info->value);
+            } else {
+               const char *file_name;
+               switch (chan_info->file) {
+               case TGSI_FILE_CONSTANT:
+                  file_name = "CONST";
+                  break;
+               case TGSI_FILE_INPUT:
+                  file_name = "IN";
+                  break;
+               default:
+                  file_name = "???";
+                  break;
+               }
+               debug_printf("%s[%u].%c",
+                            file_name,
+                            chan_info->index,
+                            "xyzw01"[chan_info->swizzle]);
+            }
+            debug_printf("\n");
+         }
+      }
+   }
+}
+
+
+/**
+ * Detect any direct relationship between the output color
+ */
+void
+lp_build_tgsi_info(const struct tgsi_token *tokens,
+                   struct lp_tgsi_info *info)
+{
+   struct tgsi_parse_context parse;
+   struct analysis_context ctx;
+   unsigned index;
+   unsigned chan;
+
+   memset(info, 0, sizeof *info);
+
+   tgsi_scan_shader(tokens, &info->base);
+
+   memset(&ctx, 0, sizeof ctx);
+   ctx.info = info;
+
+   tgsi_parse_init(&parse, tokens);
+
+   while (!tgsi_parse_end_of_tokens(&parse)) {
+      tgsi_parse_token(&parse);
+
+      switch (parse.FullToken.Token.Type) {
+      case TGSI_TOKEN_TYPE_DECLARATION:
+         break;
+
+      case TGSI_TOKEN_TYPE_INSTRUCTION:
+         {
+            struct tgsi_full_instruction *inst =
+                  &parse.FullToken.FullInstruction;
+
+            if (inst->Instruction.Opcode == TGSI_OPCODE_END ||
+                inst->Instruction.Opcode == TGSI_OPCODE_BGNSUB) {
+               /* We reached the end of main function body. */
+               goto finished;
+            }
+
+            analyse_instruction(&ctx, inst);
+         }
+         break;
+
+      case TGSI_TOKEN_TYPE_IMMEDIATE:
+         {
+            const unsigned size =
+                  parse.FullToken.FullImmediate.Immediate.NrTokens - 1;
+            assert(size <= 4);
+            if (ctx.num_imms < Elements(ctx.imm)) {
+               for (chan = 0; chan < size; ++chan) {
+                  ctx.imm[ctx.num_imms][chan] =
+                        parse.FullToken.FullImmediate.u[chan].Float;
+               }
+               ++ctx.num_imms;
+            }
+         }
+         break;
+
+      case TGSI_TOKEN_TYPE_PROPERTY:
+         break;
+
+      default:
+         assert(0);
+      }
+   }
+finished:
+
+   tgsi_parse_free(&parse);
+
+
+   /*
+    * Link the output color values.
+    */
+
+   for (index = 0; index < PIPE_MAX_COLOR_BUFS; ++index) {
+      const struct lp_tgsi_channel_info null_output[4];
+      info->cbuf[index] = null_output;
+   }
+
+   for (index = 0; index < info->base.num_outputs; ++index) {
+      unsigned semantic_name = info->base.output_semantic_name[index];
+      unsigned semantic_index = info->base.output_semantic_index[index];
+      if (semantic_name == TGSI_SEMANTIC_COLOR &&
+          semantic_index < PIPE_MAX_COLOR_BUFS) {
+         info->cbuf[semantic_index] = info->output[index];
+      }
+   }
+
+   if (gallivm_debug & GALLIVM_DEBUG_TGSI) {
+      dump_info(tokens, info);
+   }
+}