Comments about texture instructions and the src regs

2 files changed, 22 insertions, 11 deletions

diff --git a/src/mesa/pipe/tgsi/exec/tgsi_exec.c b/src/mesa/pipe/tgsi/exec/tgsi_exec.c
index f577f004d71..d98f46cc0db 100644
--- a/src/mesa/pipe/tgsi/exec/tgsi_exec.c
+++ b/src/mesa/pipe/tgsi/exec/tgsi_exec.c
@@ -1996,15 +1996,15 @@ exec_instruction(
 
    case TGSI_OPCODE_TEX:
       /* simple texture lookup */
-      /* src[0] is the texcoord */
-      /* src[1] is the sampler unit */
+      /* src[0] = texcoord */
+      /* src[1] = sampler unit */
       exec_tex(mach, inst, FALSE);
       break;
 
    case TGSI_OPCODE_TXB:
       /* Texture lookup with lod bias */
-      /* src[0] is the texcoord (src[0].w = load bias) */
-      /* src[1] is the sampler unit */
+      /* src[0] = texcoord (src[0].w = load bias) */
+      /* src[1] = sampler unit */
       exec_tex(mach, inst, TRUE);
       break;
 
@@ -2013,9 +2013,17 @@ exec_instruction(
       /* src[0] = texcoord */
       /* src[1] = d[strq]/dx */
       /* src[2] = d[strq]/dy */
+      /* src[3] = sampler unit */
       assert (0);
       break;
 
+   case TGSI_OPCODE_TXL:
+      /* Texture lookup with explit LOD */
+      /* src[0] = texcoord (src[0].w = load bias) */
+      /* src[1] = sampler unit */
+      exec_tex(mach, inst, TRUE);
+      break;
+
    case TGSI_OPCODE_UP2H:
       assert (0);
       break;
@@ -2157,10 +2165,6 @@ exec_instruction(
       }
       break;
 
-   case TGSI_OPCODE_TXL:
-      assert (0);
-      break;
-
    case TGSI_OPCODE_IF:
       /* push CondMask */
       assert(mach->CondStackTop < TGSI_EXEC_MAX_COND_NESTING);
diff --git a/src/mesa/state_tracker/st_mesa_to_tgsi.c b/src/mesa/state_tracker/st_mesa_to_tgsi.c
index 131e50becea..621159eb858 100644
--- a/src/mesa/state_tracker/st_mesa_to_tgsi.c
+++ b/src/mesa/state_tracker/st_mesa_to_tgsi.c
@@ -459,6 +459,7 @@ compile_instruction(
       fullinst->Instruction.Opcode = TGSI_OPCODE_SWZ;

       break;

    case OPCODE_TEX:

+      /* ordinary texture lookup */

       fullinst->Instruction.Opcode = TGSI_OPCODE_TEX;

       fullinst->Instruction.NumSrcRegs = 2;

       fullinst->InstructionExtTexture.Texture = map_texture_target( inst->TexSrcTarget );

@@ -466,6 +467,7 @@ compile_instruction(
       fullinst->FullSrcRegisters[1].SrcRegister.Index = inst->TexSrcUnit;

       break;

    case OPCODE_TXB:

+      /* texture lookup with LOD bias */

       fullinst->Instruction.Opcode = TGSI_OPCODE_TXB;

       fullinst->Instruction.NumSrcRegs = 2;

       fullinst->InstructionExtTexture.Texture = map_texture_target( inst->TexSrcTarget );

@@ -473,13 +475,16 @@ compile_instruction(
       fullinst->FullSrcRegisters[1].SrcRegister.Index = inst->TexSrcUnit;

       break;

    case OPCODE_TXD:

+      /* texture lookup with explicit partial derivatives */

       fullinst->Instruction.Opcode = TGSI_OPCODE_TXD;

-      fullinst->Instruction.NumSrcRegs = 2;

+      fullinst->Instruction.NumSrcRegs = 4;

       fullinst->InstructionExtTexture.Texture = map_texture_target( inst->TexSrcTarget );

-      fullinst->FullSrcRegisters[1].SrcRegister.File = TGSI_FILE_SAMPLER;

-      fullinst->FullSrcRegisters[1].SrcRegister.Index = inst->TexSrcUnit;

+      /* src[0] = coord, src[1] = d[strq]/dx, src[2] = d[strq]/dy */

+      fullinst->FullSrcRegisters[3].SrcRegister.File = TGSI_FILE_SAMPLER;

+      fullinst->FullSrcRegisters[3].SrcRegister.Index = inst->TexSrcUnit;

       break;

    case OPCODE_TXL:

+      /* texture lookup with explicit LOD */

       fullinst->Instruction.Opcode = TGSI_OPCODE_TXL;

       fullinst->Instruction.NumSrcRegs = 2;

       fullinst->InstructionExtTexture.Texture = map_texture_target( inst->TexSrcTarget );

@@ -487,6 +492,8 @@ compile_instruction(
       fullinst->FullSrcRegisters[1].SrcRegister.Index = inst->TexSrcUnit;

       break;

    case OPCODE_TXP:

+      /* texture lookup with divide by Q component */

+      /* convert to TEX w/ special flag for division */

       fullinst->Instruction.Opcode = TGSI_OPCODE_TEX;

       fullinst->Instruction.NumSrcRegs = 2;

       fullinst->InstructionExtTexture.Texture = map_texture_target( inst->TexSrcTarget );