i915_fragprog.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * 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 above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * 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 TUNGSTEN GRAPHICS 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.
 * 
 **************************************************************************/

#include "glheader.h"
#include "macros.h"
#include "enums.h"

#include "shader/prog_instruction.h"
#include "shader/prog_parameter.h"
#include "shader/program.h"
#include "shader/programopt.h"

#include "tnl/tnl.h"
#include "tnl/t_context.h"

#include "intel_batchbuffer.h"

#include "i915_reg.h"
#include "i915_context.h"
#include "i915_program.h"

static const GLfloat sin_quad_constants[2][4] = {
   {
      2.0,
      -1.0,
      .5,
      .75
   },
   {
      4.0,
      -4.0,
      1.0 / (2.0 * M_PI),
      .2225
   }
};

static const GLfloat sin_constants[4] = { 1.0,
   -1.0 / (3 * 2 * 1),
   1.0 / (5 * 4 * 3 * 2 * 1),
   -1.0 / (7 * 6 * 5 * 4 * 3 * 2 * 1)
};

/* 1, -1/2!, 1/4!, -1/6! */
static const GLfloat cos_constants[4] = { 1.0,
   -1.0 / (2 * 1),
   1.0 / (4 * 3 * 2 * 1),
   -1.0 / (6 * 5 * 4 * 3 * 2 * 1)
};

/**
 * Retrieve a ureg for the given source register.  Will emit
 * constants, apply swizzling and negation as needed.
 */
static GLuint
src_vector(struct i915_fragment_program *p,
           const struct prog_src_register *source,
           const struct gl_fragment_program *program)
{
   GLuint src;

   switch (source->File) {

      /* Registers:
       */
   case PROGRAM_TEMPORARY:
      if (source->Index >= I915_MAX_TEMPORARY) {
         i915_program_error(p, "Exceeded max temporary reg");
         return 0;
      }
      src = UREG(REG_TYPE_R, source->Index);
      break;
   case PROGRAM_INPUT:
      switch (source->Index) {
      case FRAG_ATTRIB_WPOS:
         src = i915_emit_decl(p, REG_TYPE_T, p->wpos_tex, D0_CHANNEL_ALL);
         break;
      case FRAG_ATTRIB_COL0:
         src = i915_emit_decl(p, REG_TYPE_T, T_DIFFUSE, D0_CHANNEL_ALL);
         break;
      case FRAG_ATTRIB_COL1:
         src = i915_emit_decl(p, REG_TYPE_T, T_SPECULAR, D0_CHANNEL_XYZ);
         src = swizzle(src, X, Y, Z, ONE);
         break;
      case FRAG_ATTRIB_FOGC:
         src = i915_emit_decl(p, REG_TYPE_T, T_FOG_W, D0_CHANNEL_W);
         src = swizzle(src, W, ZERO, ZERO, ONE);
         break;
      case FRAG_ATTRIB_TEX0:
      case FRAG_ATTRIB_TEX1:
      case FRAG_ATTRIB_TEX2:
      case FRAG_ATTRIB_TEX3:
      case FRAG_ATTRIB_TEX4:
      case FRAG_ATTRIB_TEX5:
      case FRAG_ATTRIB_TEX6:
      case FRAG_ATTRIB_TEX7:
         src = i915_emit_decl(p, REG_TYPE_T,
                              T_TEX0 + (source->Index - FRAG_ATTRIB_TEX0),
                              D0_CHANNEL_ALL);
         break;

      default:
         i915_program_error(p, "Bad source->Index");
         return 0;
      }
      break;

      /* Various paramters and env values.  All emitted to
       * hardware as program constants.
       */
   case PROGRAM_LOCAL_PARAM:
      src = i915_emit_param4fv(p, program->Base.LocalParams[source->Index]);
      break;

   case PROGRAM_ENV_PARAM:
      src =
         i915_emit_param4fv(p,
                            p->ctx->FragmentProgram.Parameters[source->
                                                               Index]);
      break;

   case PROGRAM_CONSTANT:
   case PROGRAM_STATE_VAR:
   case PROGRAM_NAMED_PARAM:
      src =
         i915_emit_param4fv(p,
                            program->Base.Parameters->ParameterValues[source->
                                                                      Index]);
      break;

   default:
      i915_program_error(p, "Bad source->File");
      return 0;
   }

   src = swizzle(src,
                 GET_SWZ(source->Swizzle, 0),
                 GET_SWZ(source->Swizzle, 1),
                 GET_SWZ(source->Swizzle, 2), GET_SWZ(source->Swizzle, 3));

   if (source->NegateBase)
      src = negate(src,
                   GET_BIT(source->NegateBase, 0),
                   GET_BIT(source->NegateBase, 1),
                   GET_BIT(source->NegateBase, 2),
                   GET_BIT(source->NegateBase, 3));

   return src;
}


static GLuint
get_result_vector(struct i915_fragment_program *p,
                  const struct prog_instruction *inst)
{
   switch (inst->DstReg.File) {
   case PROGRAM_OUTPUT:
      switch (inst->DstReg.Index) {
      case FRAG_RESULT_COLR:
         return UREG(REG_TYPE_OC, 0);
      case FRAG_RESULT_DEPR:
         p->depth_written = 1;
         return UREG(REG_TYPE_OD, 0);
      default:
         i915_program_error(p, "Bad inst->DstReg.Index");
         return 0;
      }
   case PROGRAM_TEMPORARY:
      return UREG(REG_TYPE_R, inst->DstReg.Index);
   default:
      i915_program_error(p, "Bad inst->DstReg.File");
      return 0;
   }
}

static GLuint
get_result_flags(const struct prog_instruction *inst)
{
   GLuint flags = 0;

   if (inst->SaturateMode == SATURATE_ZERO_ONE)
      flags |= A0_DEST_SATURATE;
   if (inst->DstReg.WriteMask & WRITEMASK_X)
      flags |= A0_DEST_CHANNEL_X;
   if (inst->DstReg.WriteMask & WRITEMASK_Y)
      flags |= A0_DEST_CHANNEL_Y;
   if (inst->DstReg.WriteMask & WRITEMASK_Z)
      flags |= A0_DEST_CHANNEL_Z;
   if (inst->DstReg.WriteMask & WRITEMASK_W)
      flags |= A0_DEST_CHANNEL_W;

   return flags;
}

static GLuint
translate_tex_src_target(struct i915_fragment_program *p, GLubyte bit)
{
   switch (bit) {
   case TEXTURE_1D_INDEX:
      return D0_SAMPLE_TYPE_2D;
   case TEXTURE_2D_INDEX:
      return D0_SAMPLE_TYPE_2D;
   case TEXTURE_RECT_INDEX:
      return D0_SAMPLE_TYPE_2D;
   case TEXTURE_3D_INDEX:
      return D0_SAMPLE_TYPE_VOLUME;
   case TEXTURE_CUBE_INDEX:
      return D0_SAMPLE_TYPE_CUBE;
   default:
      i915_program_error(p, "TexSrcBit");
      return 0;
   }
}

#define EMIT_TEX( OP )						\
do {								\
   GLuint dim = translate_tex_src_target( p, inst->TexSrcTarget );	\
   GLuint sampler = i915_emit_decl(p, REG_TYPE_S,		\
				  inst->TexSrcUnit, dim);	\
   GLuint coord = src_vector( p, &inst->SrcReg[0], program);	\
   /* Texel lookup */						\
								\
   i915_emit_texld( p, get_live_regs(p, inst),						\
	       get_result_vector( p, inst ),			\
	       get_result_flags( inst ),			\
	       sampler,						\
	       coord,						\
	       OP);						\
} while (0)

#define EMIT_ARITH( OP, N )						\
do {									\
   i915_emit_arith( p,							\
	       OP,							\
	       get_result_vector( p, inst ), 				\
	       get_result_flags( inst ), 0,			\
	       (N<1)?0:src_vector( p, &inst->SrcReg[0], program),	\
	       (N<2)?0:src_vector( p, &inst->SrcReg[1], program),	\
	       (N<3)?0:src_vector( p, &inst->SrcReg[2], program));	\
} while (0)

#define EMIT_1ARG_ARITH( OP ) EMIT_ARITH( OP, 1 )
#define EMIT_2ARG_ARITH( OP ) EMIT_ARITH( OP, 2 )
#define EMIT_3ARG_ARITH( OP ) EMIT_ARITH( OP, 3 )

/* 
 * TODO: consider moving this into core 
 */
static void calc_live_regs( struct i915_fragment_program *p )
{
    const struct gl_fragment_program *program = p->ctx->FragmentProgram._Current;
    GLuint regsUsed = 0xffff0000;
    GLint i;
   
    for (i = program->Base.NumInstructions - 1; i >= 0; i--) {
        struct prog_instruction *inst = &program->Base.Instructions[i];
        int opArgs = _mesa_num_inst_src_regs(inst->Opcode);
        int a;

        /* Register is written to: unmark as live for this and preceeding ops */ 
        if (inst->DstReg.File == PROGRAM_TEMPORARY)
            regsUsed &= ~(1 << inst->DstReg.Index);

        for (a = 0; a < opArgs; a++) {
            /* Register is read from: mark as live for this and preceeding ops */ 
            if (inst->SrcReg[a].File == PROGRAM_TEMPORARY)
                regsUsed |= 1 << inst->SrcReg[a].Index;
        }

        p->usedRegs[i] = regsUsed;
    }
}

static GLuint get_live_regs( struct i915_fragment_program *p, 
                             const struct prog_instruction *inst )
{
    const struct gl_fragment_program *program = p->ctx->FragmentProgram._Current;
    GLuint nr = inst - program->Base.Instructions;

    return p->usedRegs[nr];
}
 

/* Possible concerns:
 *
 * SIN, COS -- could use another taylor step?
 * LIT      -- results seem a little different to sw mesa
 * LOG      -- different to mesa on negative numbers, but this is conformant.
 * 
 * Parse failures -- Mesa doesn't currently give a good indication
 * internally whether a particular program string parsed or not.  This
 * can lead to confusion -- hopefully we cope with it ok now.
 *
 */
static void
upload_program(struct i915_fragment_program *p)
{
   const struct gl_fragment_program *program =
      p->ctx->FragmentProgram._Current;
   const struct prog_instruction *inst = program->Base.Instructions;

/*    _mesa_debug_fp_inst(program->Base.NumInstructions, inst); */

   /* Is this a parse-failed program?  Ensure a valid program is
    * loaded, as the flagging of an error isn't sufficient to stop
    * this being uploaded to hardware.
    */
   if (inst[0].Opcode == OPCODE_END) {
      GLuint tmp = i915_get_utemp(p);
      i915_emit_arith(p,
                      A0_MOV,
                      UREG(REG_TYPE_OC, 0),
                      A0_DEST_CHANNEL_ALL, 0,
                      swizzle(tmp, ONE, ZERO, ONE, ONE), 0, 0);
      return;
   }

   if (program->Base.NumInstructions > I915_MAX_INSN) {
       i915_program_error( p, "Exceeded max instructions" );
       return;
    }

   /* Not always needed:
    */
   calc_live_regs(p);

   while (1) {
      GLuint src0, src1, src2, flags;
      GLuint tmp = 0, consts0 = 0, consts1 = 0;

      switch (inst->Opcode) {
      case OPCODE_ABS:
         src0 = src_vector(p, &inst->SrcReg[0], program);
         i915_emit_arith(p,
                         A0_MAX,
                         get_result_vector(p, inst),
                         get_result_flags(inst), 0,
                         src0, negate(src0, 1, 1, 1, 1), 0);
         break;

      case OPCODE_ADD:
         EMIT_2ARG_ARITH(A0_ADD);
         break;

      case OPCODE_CMP:
         src0 = src_vector(p, &inst->SrcReg[0], program);
         src1 = src_vector(p, &inst->SrcReg[1], program);
         src2 = src_vector(p, &inst->SrcReg[2], program);
         i915_emit_arith(p, A0_CMP, get_result_vector(p, inst), get_result_flags(inst), 0, src0, src2, src1);   /* NOTE: order of src2, src1 */
         break;

      case OPCODE_COS:
         src0 = src_vector(p, &inst->SrcReg[0], program);
         tmp = i915_get_utemp(p);
	 consts0 = i915_emit_const4fv(p, sin_quad_constants[0]);
	 consts1 = i915_emit_const4fv(p, sin_quad_constants[1]);

	 /* Reduce range from repeating about [-pi,pi] to [-1,1] */
         i915_emit_arith(p,
                         A0_MAD,
                         tmp, A0_DEST_CHANNEL_X, 0,
                         src0,
			 swizzle(consts1, Z, ZERO, ZERO, ZERO), /* 1/(2pi) */
			 swizzle(consts0, W, ZERO, ZERO, ZERO)); /* .75 */

         i915_emit_arith(p, A0_FRC, tmp, A0_DEST_CHANNEL_X, 0, tmp, 0, 0);

	 i915_emit_arith(p,
			 A0_MAD,
			 tmp, A0_DEST_CHANNEL_X, 0,
			 tmp,
			 swizzle(consts0, X, ZERO, ZERO, ZERO), /* 2 */
			 swizzle(consts0, Y, ZERO, ZERO, ZERO)); /* -1 */

	 /* Compute COS with the same calculation used for SIN, but a
	  * different source range has been mapped to [-1,1] this time.