C++ UREG函数代码示例

uint
i915_emit_const1f(struct i915_fp_compile * p, float c0)
{
   struct i915_fragment_shader *ifs = p->shader;
   unsigned reg, idx;

   if (c0 == 0.0)
      return swizzle(UREG(REG_TYPE_R, 0), ZERO, ZERO, ZERO, ZERO);
   if (c0 == 1.0)
      return swizzle(UREG(REG_TYPE_R, 0), ONE, ONE, ONE, ONE);

   for (reg = 0; reg < I915_MAX_CONSTANT; reg++) {
      if (ifs->constant_flags[reg] == I915_CONSTFLAG_USER)
         continue;
      for (idx = 0; idx < 4; idx++) {
         if (!(ifs->constant_flags[reg] & (1 << idx)) ||
             ifs->constants[reg][idx] == c0) {
            ifs->constants[reg][idx] = c0;
            ifs->constant_flags[reg] |= 1 << idx;
            if (reg + 1 > ifs->num_constants)
               ifs->num_constants = reg + 1;
            return swizzle(UREG(REG_TYPE_CONST, reg), idx, ZERO, ZERO, ONE);
         }
      }
   }

   i915_program_error(p, "i915_emit_const1f: out of constants");
   return 0;
}

GLuint
i915_emit_const1f(struct i915_fragment_program * p, GLfloat c0)
{
   GLint reg, idx;

   if (c0 == 0.0)
      return swizzle(UREG(REG_TYPE_R, 0), ZERO, ZERO, ZERO, ZERO);
   if (c0 == 1.0)
      return swizzle(UREG(REG_TYPE_R, 0), ONE, ONE, ONE, ONE);

   for (reg = 0; reg < I915_MAX_CONSTANT; reg++) {
      if (p->constant_flags[reg] == I915_CONSTFLAG_PARAM)
         continue;
      for (idx = 0; idx < 4; idx++) {
         if (!(p->constant_flags[reg] & (1 << idx)) ||
             p->constant[reg][idx] == c0) {
            p->constant[reg][idx] = c0;
            p->constant_flags[reg] |= 1 << idx;
            if (reg + 1 > p->nr_constants)
               p->nr_constants = reg + 1;
            return swizzle(UREG(REG_TYPE_CONST, reg), idx, ZERO, ZERO, ONE);
         }
      }
   }

   fprintf(stderr, "%s: out of constants\n", __FUNCTION__);
   p->error = 1;
   return 0;
}

/**
 * Construct a ureg for a destination register.
 */
static uint
get_result_vector(struct i915_fp_compile *p,
                  const struct i915_full_dst_register *dest)
{
   switch (dest->Register.File) {
   case TGSI_FILE_OUTPUT:
      {
         uint sem_name = p->shader->info.output_semantic_name[dest->Register.Index];
         switch (sem_name) {
         case TGSI_SEMANTIC_POSITION:
            return UREG(REG_TYPE_OD, 0);
         case TGSI_SEMANTIC_COLOR:
            return UREG(REG_TYPE_OC, 0);
         default:
            i915_program_error(p, "Bad inst->DstReg.Index/semantics");
            return 0;
         }
      }
   case TGSI_FILE_TEMPORARY:
      return UREG(REG_TYPE_R, dest->Register.Index);
   default:
      i915_program_error(p, "Bad inst->DstReg.File");
      return 0;
   }
}

GLuint
i915_emit_const4f(struct i915_fragment_program * p,
                  GLfloat c0, GLfloat c1, GLfloat c2, GLfloat c3)
{
   GLint reg;

   for (reg = 0; reg < I915_MAX_CONSTANT; reg++) {
      if (p->constant_flags[reg] == 0xf &&
          p->constant[reg][0] == c0 &&
          p->constant[reg][1] == c1 &&
          p->constant[reg][2] == c2 && p->constant[reg][3] == c3) {
         return UREG(REG_TYPE_CONST, reg);
      }
      else if (p->constant_flags[reg] == 0) {
         p->constant[reg][0] = c0;
         p->constant[reg][1] = c1;
         p->constant[reg][2] = c2;
         p->constant[reg][3] = c3;
         p->constant_flags[reg] = 0xf;
         if (reg + 1 > p->nr_constants)
            p->nr_constants = reg + 1;
         return UREG(REG_TYPE_CONST, reg);
      }
   }

   fprintf(stderr, "%s: out of constants\n", __FUNCTION__);
   p->error = 1;
   return 0;
}

GLuint
i915_emit_param4fv(struct i915_fragment_program * p, const GLfloat * values)
{
   GLint reg, i;

   for (i = 0; i < p->nr_params; i++) {
      if (p->param[i].values == values)
         return UREG(REG_TYPE_CONST, p->param[i].reg);
   }


   for (reg = 0; reg < I915_MAX_CONSTANT; reg++) {
      if (p->constant_flags[reg] == 0) {
         p->constant_flags[reg] = I915_CONSTFLAG_PARAM;
         i = p->nr_params++;

         p->param[i].values = values;
         p->param[i].reg = reg;
         p->params_uptodate = 0;

         if (reg + 1 > p->nr_constants)
            p->nr_constants = reg + 1;
         return UREG(REG_TYPE_CONST, reg);
      }
   }

   fprintf(stderr, "%s: out of constants\n", __FUNCTION__);
   p->error = 1;
   return 0;
}

uint
i915_emit_const4f(struct i915_fp_compile * p,
                  float c0, float c1, float c2, float c3)
{
   struct i915_fragment_shader *ifs = p->shader;
   unsigned reg;

   // XXX emit swizzle here for 0, 1, -1 and any combination thereof
   // we can use swizzle + neg for that
   for (reg = 0; reg < I915_MAX_CONSTANT; reg++) {
      if (ifs->constant_flags[reg] == 0xf &&
          ifs->constants[reg][0] == c0 &&
          ifs->constants[reg][1] == c1 &&
          ifs->constants[reg][2] == c2 &&
          ifs->constants[reg][3] == c3) {
         return UREG(REG_TYPE_CONST, reg);
      }
      else if (ifs->constant_flags[reg] == 0) {

         ifs->constants[reg][0] = c0;
         ifs->constants[reg][1] = c1;
         ifs->constants[reg][2] = c2;
         ifs->constants[reg][3] = c3;
         ifs->constant_flags[reg] = 0xf;
         if (reg + 1 > ifs->num_constants)
            ifs->num_constants = reg + 1;
         return UREG(REG_TYPE_CONST, reg);
      }
   }

   i915_program_error(p, "i915_emit_const4f: out of constants");
   return 0;
}

GLuint
i915_emit_decl(struct i915_fragment_program *p,
               GLuint type, GLuint nr, GLuint d0_flags)
{
   GLuint reg = UREG(type, nr);

   if (type == REG_TYPE_T) {
      if (p->decl_t & (1 << nr))
         return reg;

      p->decl_t |= (1 << nr);
   }
   else if (type == REG_TYPE_S) {
      if (p->decl_s & (1 << nr))
         return reg;

      p->decl_s |= (1 << nr);
   }
   else
      return reg;

   *(p->decl++) = (D0_DCL | D0_DEST(reg) | d0_flags);
   *(p->decl++) = D1_MBZ;
   *(p->decl++) = D2_MBZ;

   p->nr_decl_insn++;
   return reg;
}

uint
i915_emit_decl(struct i915_fp_compile *p,
               uint type, uint nr, uint d0_flags)
{
   uint reg = UREG(type, nr);

   if (type == REG_TYPE_T) {
      if (p->decl_t & (1 << nr))
         return reg;

      p->decl_t |= (1 << nr);
   }
   else if (type == REG_TYPE_S) {
      if (p->decl_s & (1 << nr))
         return reg;

      p->decl_s |= (1 << nr);
   }
   else
      return reg;

   if (p->decl< p->declarations + I915_PROGRAM_SIZE) {
      *(p->decl++) = (D0_DCL | D0_DEST(reg) | d0_flags);
      *(p->decl++) = D1_MBZ;
      *(p->decl++) = D2_MBZ;
   }
   else
      i915_program_error(p, "Out of declarations");

   p->nr_decl_insn++;
   return reg;
}

GLuint
i915_emit_arith(struct i915_fragment_program * p,
                GLuint op,
                GLuint dest,
                GLuint mask,
                GLuint saturate, GLuint src0, GLuint src1, GLuint src2)
{
   GLuint c[3];
   GLuint nr_const = 0;

   assert(GET_UREG_TYPE(dest) != REG_TYPE_CONST);
   dest = UREG(GET_UREG_TYPE(dest), GET_UREG_NR(dest));
   assert(dest);

   if (GET_UREG_TYPE(src0) == REG_TYPE_CONST)
      c[nr_const++] = 0;
   if (GET_UREG_TYPE(src1) == REG_TYPE_CONST)
      c[nr_const++] = 1;
   if (GET_UREG_TYPE(src2) == REG_TYPE_CONST)
      c[nr_const++] = 2;

   /* Recursively call this function to MOV additional const values
    * into temporary registers.  Use utemp registers for this -
    * currently shouldn't be possible to run out, but keep an eye on
    * this.
    */
   if (nr_const > 1) {
      GLuint s[3], first, i, old_utemp_flag;

      s[0] = src0;
      s[1] = src1;
      s[2] = src2;
      old_utemp_flag = p->utemp_flag;

      first = GET_UREG_NR(s[c[0]]);
      for (i = 1; i < nr_const; i++) {
         if (GET_UREG_NR(s[c[i]]) != first) {
            GLuint tmp = i915_get_utemp(p);

            i915_emit_arith(p, A0_MOV, tmp, A0_DEST_CHANNEL_ALL, 0,
                            s[c[i]], 0, 0);
            s[c[i]] = tmp;
         }
      }

      src0 = s[0];
      src1 = s[1];
      src2 = s[2];
      p->utemp_flag = old_utemp_flag;   /* restore */
   }

   *(p->csr++) = (op | A0_DEST(dest) | mask | saturate | A0_SRC0(src0));
   *(p->csr++) = (A1_SRC0(src0) | A1_SRC1(src1));
   *(p->csr++) = (A2_SRC1(src1) | A2_SRC2(src2));

   p->nr_alu_insn++;
   return dest;
}

static GLuint get_dest( struct i915_fragment_program *p, int unit )
{
   if (p->ctx->_TriangleCaps & DD_SEPARATE_SPECULAR)
      return i915_get_temp( p );
   else if (unit != p->last_tex_stage)
      return i915_get_temp( p );
   else
      return UREG(REG_TYPE_OC, 0);
}

static GLuint get_free_rreg (struct i915_fragment_program *p, 
                             GLuint live_regs)
{
    int bit = ffs(~live_regs);
    if (!bit) {
        i915_program_error(p, "Can't find free R reg");
        return UREG_BAD;
    }
    return UREG(REG_TYPE_R, bit - 1);
}

GLuint i915_emit_texld( struct i915_fragment_program *p,
			GLuint dest,
			GLuint destmask,
			GLuint sampler,
			GLuint coord,
			GLuint op )
{
   if (coord != UREG(GET_UREG_TYPE(coord), GET_UREG_NR(coord))) {
      /* No real way to work around this in the general case - need to
       * allocate and declare a new temporary register (a utemp won't
       * do).  Will fallback for now.
       */
      i915_program_error(p, "Can't (yet) swizzle TEX arguments");
      return 0;
   }

   /* Don't worry about saturate as we only support  
    */
   if (destmask != A0_DEST_CHANNEL_ALL) {
      GLuint tmp = i915_get_utemp(p);
      i915_emit_texld( p, tmp, A0_DEST_CHANNEL_ALL, sampler, coord, op );
      i915_emit_arith( p, A0_MOV, dest, destmask, 0, tmp, 0, 0 );
      return dest;
   }
   else {
      assert(GET_UREG_TYPE(dest) != REG_TYPE_CONST);
      assert(dest = UREG(GET_UREG_TYPE(dest), GET_UREG_NR(dest)));

      if (GET_UREG_TYPE(coord) != REG_TYPE_T) {
	 p->nr_tex_indirect++;
      }

      *(p->csr++) = (op | 
		     T0_DEST( dest ) |
		     T0_SAMPLER( sampler ));

      *(p->csr++) = T1_ADDRESS_REG( coord );
      *(p->csr++) = T2_MBZ;

      p->nr_tex_insn++;
      return dest;
   }
}

/**
 * Get unpreserved temporary, a temp whose value is not preserved between
 * PS program phases.
 */
uint
i915_get_utemp(struct i915_fp_compile * p)
{
   int bit = ffs(~p->utemp_flag);
   if (!bit) {
      i915_program_error(p, "i915_get_utemp: out of temporaries");
      return 0;
   }

   p->utemp_flag |= 1 << (bit - 1);
   return UREG(REG_TYPE_U, (bit - 1));
}

GLuint
i915_get_utemp(struct i915_fragment_program * p)
{
   int bit = ffs(~p->utemp_flag);
   if (!bit) {
      fprintf(stderr, "%s: out of temporaries\n", __FILE__);
      exit(1);
   }

   p->utemp_flag |= 1 << (bit - 1);
   return UREG(REG_TYPE_U, (bit - 1));
}

/* Rather than trying to intercept and jiggle depth writes during
 * emit, just move the value into its correct position at the end of
 * the program:
 */
static void
fixup_depth_write(struct i915_fragment_program *p)
{
   if (p->depth_written) {
      GLuint depth = UREG(REG_TYPE_OD, 0);

      i915_emit_arith(p,
                      A0_MOV,
                      depth, A0_DEST_CHANNEL_W, 0,
                      swizzle(depth, X, Y, Z, Z), 0, 0);
   }
}