/*
 * Copyright © 2009 Intel Corporation
 *
 * 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, sublicense,
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 */

/**
 * \file prog_parameter_layout.c
 * \brief Helper functions to layout storage for program parameters
 *
 * \author Ian Romanick <ian.d.romanick@intel.com>
 */

#include "main/compiler.h"
#include "main/mtypes.h"
#include "prog_parameter.h"
#include "prog_parameter_layout.h"
#include "prog_instruction.h"
#include "program_parser.h"

unsigned
_mesa_combine_swizzles(unsigned base, unsigned applied)
{
   unsigned swiz = 0;
   unsigned i;

   for (i = 0; i < 4; i++) {
      const unsigned s = GET_SWZ(applied, i);

      swiz |= ((s <= SWIZZLE_W) ? GET_SWZ(base, s) : s) << (i * 3);
   }

   return swiz;
}


/**
 * Copy indirect access array from one parameter list to another
 *
 * \param src   Parameter array copied from
 * \param dst   Parameter array copied to
 * \param first Index of first element in \c src to copy
 * \param count Number of elements to copy
 *
 * \return
 * The location in \c dst of the first element copied from \c src on
 * success.  -1 on failure.
 *
 * \warning
 * This function assumes that there is already enough space available in
 * \c dst to hold all of the elements that will be copied over.
 */
static int
copy_indirect_accessed_array(struct gl_program_parameter_list *src,
			     struct gl_program_parameter_list *dst,
			     unsigned first, unsigned count)
{
   const int base = dst->NumParameters;
   unsigned i, j;

   for (i = first; i < (first + count); i++) {
      struct gl_program_parameter *curr = & src->Parameters[i];

      if (curr->Type == PROGRAM_CONSTANT) {
	 j = dst->NumParameters;
      } else {
	 for (j = 0; j < dst->NumParameters; j++) {
	    if (memcmp(dst->Parameters[j].StateIndexes, curr->StateIndexes, 
		       sizeof(curr->StateIndexes)) == 0) {
	       return -1;
	    }
	 }
      }

      assert(j == dst->NumParameters);

      /* copy src parameter [i] to dest parameter [j] */
      memcpy(& dst->Parameters[j], curr,
	     sizeof(dst->Parameters[j]));
      memcpy(dst->ParameterValues[j], src->ParameterValues[i],
	     sizeof(GLfloat) * 4);

      /* Pointer to the string name was copied.  Null-out src param name
       * to prevent double free later.
       */
      curr->Name = NULL;

      dst->NumParameters++;
   }

   return base;
}


/**
 * XXX description???
 * \return GL_TRUE for success, GL_FALSE for failure
 */
GLboolean
_mesa_layout_parameters(struct asm_parser_state *state)
{
   struct gl_program_parameter_list *layout;
   struct asm_instruction *inst;
   unsigned i;

   layout =
      _mesa_new_parameter_list_sized(state->prog->Parameters->NumParameters);

   /* PASS 1:  Move any parameters that are accessed indirectly from the
    * original parameter list to the new parameter list.
    */
   for (inst = state->inst_head; inst != NULL; inst = inst->next) {
      for (i = 0; i < 3; i++) {
	 if (inst->SrcReg[i].Base.RelAddr) {
	    /* Only attempt to add the to the new parameter list once.
	     */
	    if (!inst->SrcReg[i].Symbol->pass1_done) {
	       const int new_begin =
		  copy_indirect_accessed_array(state->prog->Parameters, layout,
		      inst->SrcReg[i].Symbol->param_binding_begin,
		      inst->SrcReg[i].Symbol->param_binding_length);

	       if (new_begin < 0) {
		  return GL_FALSE;
	       }

	       inst->SrcReg[i].Symbol->param_binding_begin = new_begin;
	       inst->SrcReg[i].Symbol->pass1_done = 1;
	    }

	    /* Previously the Index was just the offset from the parameter
	     * array.  Now that the base of the parameter array is known, the
	     * index can be updated to its actual value.
	     */
	    inst->Base.SrcReg[i] = inst->SrcReg[i].Base;
	    inst->Base.SrcReg[i].Index +=
	       inst->SrcReg[i].Symbol->param_binding_begin;
	 }
      }
   }

   /* PASS 2:  Move any parameters that are not accessed indirectly from the
    * original parameter list to the new parameter list.
    */
   for (inst = state->inst_head; inst != NULL; inst = inst->next) {
      for (i = 0; i < 3; i++) {
	 const struct gl_program_parameter *p;
	 const int idx = inst->SrcReg[i].Base.Index;
	 unsigned swizzle = SWIZZLE_NOOP;

	 /* All relative addressed operands were processed on the first
	  * pass.  Just skip them here.
	  */
	 if (inst->SrcReg[i].Base.RelAddr) {
	    continue;
	 }

	 if ((inst->SrcReg[i].Base.File <= PROGRAM_VARYING )
	     || (inst->SrcReg[i].Base.File >= PROGRAM_WRITE_ONLY)) {
	    continue;
	 }

	 inst->Base.SrcReg[i] = inst->SrcReg[i].Base;
	 p = & state->prog->Parameters->Parameters[idx];

	 switch (p->Type) {
	 case PROGRAM_CONSTANT: {
	    const float *const v =
	       state->prog->Parameters->ParameterValues[idx];

	    inst->Base.SrcReg[i].Index =
	       _mesa_add_unnamed_constant(layout, v, p->Size, & swizzle);

	    inst->Base.SrcReg[i].Swizzle = 
	       _mesa_combine_swizzles(swizzle, inst->Base.SrcReg[i].Swizzle);
	    break;
	 }

	 case PROGRAM_STATE_VAR:
	    inst->Base.SrcReg[i].Index =
	       _mesa_add_state_reference(layout, p->StateIndexes);
	    break;

	 default:
	    break;
	 }

	 inst->SrcReg[i].Base.File = p->Type;
	 inst->Base.SrcReg[i].File = p->Type;
      }
   }

   _mesa_free_parameter_list(state->prog->Parameters);
   state->prog->Parameters = layout;

   return GL_TRUE;
}
