path: root/src/gallium/drivers/i965/brw_eu.c

/*
 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
 Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
 develop this 3D driver.
 
 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 COPYRIGHT OWNER(S) 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.
 
 **********************************************************************/
 /*
  * Authors:
  *   Keith Whitwell <keith@tungstengraphics.com>
  */
  
#include "util/u_memory.h"

#include "brw_context.h"
#include "brw_defines.h"
#include "brw_eu.h"



/* How does predicate control work when execution_size != 8?  Do I
 * need to test/set for 0xffff when execution_size is 16?
 */
void brw_set_predicate_control_flag_value( struct brw_compile *p, GLuint value )
{
   p->current->header.predicate_control = BRW_PREDICATE_NONE;

   if (value != 0xff) {
      if (value != p->flag_value) {
	 brw_push_insn_state(p);
	 brw_MOV(p, brw_flag_reg(), brw_imm_uw(value));
	 p->flag_value = value;
	 brw_pop_insn_state(p);
      }

      p->current->header.predicate_control = BRW_PREDICATE_NORMAL;
   }   
}

void brw_set_predicate_control( struct brw_compile *p, GLuint pc )
{
   p->current->header.predicate_control = pc;
}

void brw_set_conditionalmod( struct brw_compile *p, GLuint conditional )
{
   p->current->header.destreg__conditionalmod = conditional;
}

void brw_set_access_mode( struct brw_compile *p, GLuint access_mode )
{
   p->current->header.access_mode = access_mode;
}

void brw_set_compression_control( struct brw_compile *p, GLboolean compression_control )
{
   p->current->header.compression_control = compression_control;
}

void brw_set_mask_control( struct brw_compile *p, GLuint value )
{
   p->current->header.mask_control = value;
}

void brw_set_saturate( struct brw_compile *p, GLuint value )
{
   p->current->header.saturate = value;
}

void brw_push_insn_state( struct brw_compile *p )
{
   assert(p->current != &p->stack[BRW_EU_MAX_INSN_STACK-1]);
   memcpy(p->current+1, p->current, sizeof(struct brw_instruction));
   p->current++;   
}

void brw_pop_insn_state( struct brw_compile *p )
{
   assert(p->current != p->stack);
   p->current--;
}


/***********************************************************************
 */
void brw_init_compile( struct brw_context *brw, struct brw_compile *p )
{
   p->brw = brw;
   p->nr_insn = 0;
   p->current = p->stack;
   memset(p->current, 0, sizeof(p->current[0]));

   /* Some defaults?
    */
   brw_set_mask_control(p, BRW_MASK_ENABLE); /* what does this do? */
   brw_set_saturate(p, 0);
   brw_set_compression_control(p, BRW_COMPRESSION_NONE);
   brw_set_predicate_control_flag_value(p, 0xff); 
}


enum pipe_error brw_get_program( struct brw_compile *p,
                                 const GLuint **data,
                                 GLuint *sz )
{
   GLuint i;

   for (i = 0; i < 8; i++)
      brw_NOP(p);

   /* Is the generated program malformed for some reason?
    */
   if (p->error)
      return PIPE_ERROR_BAD_INPUT;

   *sz = p->nr_insn * sizeof(struct brw_instruction);
   *data = (const GLuint *)p->store;
   return PIPE_OK;
}



/**
 * Subroutine calls require special attention.
 * Mesa instructions may be expanded into multiple hardware instructions
 * so the prog_instruction::BranchTarget field can't be used as an index
 * into the hardware instructions.
 *
 * The BranchTarget field isn't needed, however.  Mesa's GLSL compiler
 * emits CAL and BGNSUB instructions with labels that can be used to map
 * subroutine calls to actual subroutine code blocks.
 *
 * The structures and function here implement patching of CAL instructions
 * so they jump to the right subroutine code...
 */


/**
 * For each OPCODE_BGNSUB we create one of these.
 */
struct brw_eu_label
{
   GLuint label;     /**< the label number */
   GLuint position;  /**< the position of the brw instruction for this label */
   struct brw_eu_label *next;  /**< next in linked list */
};


/**
 * For each OPCODE_CAL we create one of these.
 */
struct brw_eu_call
{
   GLuint call_inst_pos;  /**< location of the CAL instruction */
   GLuint label;
   struct brw_eu_call *next;  /**< next in linked list */
};


/**
 * Called for each OPCODE_BGNSUB.
 */
void
brw_save_label(struct brw_compile *c, unsigned l, GLuint position)
{
   struct brw_eu_label *label = CALLOC_STRUCT(brw_eu_label);
   label->label = l;
   label->position = position;
   label->next = c->first_label;
   c->first_label = label;
}


/**
 * Called for each OPCODE_CAL.
 */
void
brw_save_call(struct brw_compile *c, GLuint label, GLuint call_pos)
{
   struct brw_eu_call *call = CALLOC_STRUCT(brw_eu_call);
   call->call_inst_pos = call_pos;
   call->label = label;
   call->next = c->first_call;
   c->first_call = call;
}


/**
 * Lookup a label, return label's position/offset.
 */
static GLuint
brw_lookup_label(struct brw_compile *c, unsigned l)
{
   const struct brw_eu_label *label;
   for (label = c->first_label; label; label = label->next) {
      if (l == label->label) {
         return label->position;
      }
   }
   abort();  /* should never happen */
   return ~0;
}


/**
 * When we're done generating code, this function is called to resolve
 * subroutine calls.
 */
void
brw_resolve_cals(struct brw_compile *c)
{
    const struct brw_eu_call *call;

    for (call = c->first_call; call; call = call->next) {
        const GLuint sub_loc = brw_lookup_label(c, call->label);
	struct brw_instruction *brw_call_inst = &c->store[call->call_inst_pos];
	struct brw_instruction *brw_sub_inst = &c->store[sub_loc];
	GLint offset = brw_sub_inst - brw_call_inst;

	/* patch brw_inst1 to point to brw_inst2 */
	brw_set_src1(brw_call_inst, brw_imm_d(offset * 16));
    }

    /* free linked list of calls */
    {
        struct brw_eu_call *call, *next;
        for (call = c->first_call; call; call = next) {
	    next = call->next;
	    FREE(call);
	}
	c->first_call = NULL;
    }

    /* free linked list of labels */
    {
        struct brw_eu_label *label, *next;
	for (label = c->first_label; label; label = next) {
	    next = label->next;
	    FREE(label);
	}
	c->first_label = NULL;
    }
}