/**********************************************************************
* plopt.c
* Load/Store Optimizations
*
* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
**********************************************************************/
/**********************************************************************
* Included Files
**********************************************************************/
#include <stdint.h>
#include <stdio.h>
#include "keywords.h"
#include "pdefs.h"
#include "pinsn16.h"
#include "popt.h"
#include "polocal.h"
#include "plopt.h"
/**********************************************************************/
int16_t LoadOptimize(void)
{
uint16_t val;
int16_t nchanges = 0;
register int16_t i;
TRACE(stderr, "[LoadOptimize]");
/* At least two pcodes are need to perform Load optimizations */
i = 0;
while (i < nops-1)
{
switch (pptr[i]->op)
{
/* Eliminate duplicate loads */
case oLDSH :
if ((pptr[i+1]->op == oLDSH) &&
(pptr[i+1]->arg1 == pptr[i]->arg1) &&
(pptr[i+1]->arg2 == pptr[i]->arg2))
{
pptr[i+1]->op = oDUPH;
pptr[i+1]->arg1 = 0;
pptr[i+1]->arg2 = 0;
nchanges++;
i += 2;
} /* end if */
else i++;
break;
/* Convert loads indexed by a constant to unindexed loads */
case oPUSH :
case oPUSHB :
/* Get the index value */
if (pptr[i]->op == oPUSH)
{
val = pptr[i]->arg2;
}
else
{
val = pptr[i]->arg1;
}
/* If the following instruction is a load, add the constant
* index value to the address and switch the opcode to the
* unindexed form.
*/
if (pptr[i+1]->op == oLDSXH)
{
pptr[i+1]->op = oLDSH;
pptr[i+1]->arg2 += val;
deletePcode (i);
nchanges++;
} /* end if */
else if (pptr[i+1]->op == oLASX)
{
pptr[i+1]->op = oLAS;
pptr[i+1]->arg2 += val;
deletePcode (i);
nchanges++;
} /* end else if */
else if (pptr[i+1]->op == oLDSXB)
{
pptr[i+1]->op = oLDSB;
pptr[i+1]->arg2 += val;
deletePcode (i);
nchanges++;
} /* end if */
else if (pptr[i+1]->op == oLDSXM)
{
pptr[i+1]->op = oLDSM;
pptr[i+1]->arg2 += val;
deletePcode (i);
nchanges++;
} /* end if */
else if (val < 256)
{
pptr[i]->op = oPUSHB;
pptr[i]->arg1 = val;
pptr[i]->arg2 = 0;
i++;
} /* end else if */
else i++;
break;
default :
i++;
break;
} /* end switch */
} /* end while */
return (nchanges);
} /* end LoadOptimize */
/**********************************************************************/
int16_t StoreOptimize (void)
{
uint16_t val;
int16_t nchanges = 0;
register int16_t i;
TRACE(stderr, "[StoreOptimize]");
/* At least two pcodes are need to perform the following Store */
/* optimizations */
i = 0;
while (i < nops-1)
{
switch (pptr[i]->op)
{
/* Eliminate store followed by load */
case oSTSH :
if ((pptr[i+1]->op == oLDSH) &&
(pptr[i+1]->arg1 == pptr[i]->arg1) &&
(pptr[i+1]->arg2 == pptr[i]->arg2))
{
pptr[i+1]->op = oSTSH;
pptr[i]->op = oDUPH;
pptr[i]->arg1 = 0;
pptr[i]->arg2 = 0;
nchanges++;
i += 2;
} /* end if */
else i++;
break;
/* Convert stores indexed by a constant to unindexed stores */
case oPUSH :
/* Get the index value */
if (pptr[i]->op == oPUSH)
{
val = pptr[i]->arg2;
}
else
{
val = pptr[i]->arg1;
}
/* If the following instruction is a store, add the constant
* index value to the address and switch the opcode to the
* unindexed form.
*/
if (i < nops-2)
{
if (pptr[i+2]->op == oSTSXH)
{
pptr[i+2]->op = oSTSH;
pptr[i+2]->arg2 += pptr[i]->arg2;
deletePcode (i);
nchanges++;
} /* end if */
else if (pptr[i+2]->op == oSTSXB)
{
pptr[i+2]->op = oSTSB;
pptr[i+2]->arg2 += pptr[i]->arg2;
deletePcode (i);
nchanges++;
} /* end if */
else i++;
} /* end if */
else i++;
break;
case oPUSHB :
if (i < nops-2)
{
if (pptr[i+2]->op == oSTSXB)
{
pptr[i+2]->op = oSTSB;
pptr[i+2]->arg2 += pptr[i]->arg2;
deletePcode (i);
nchanges++;
} /* end if */
else i++;
} /* end if */
else i++;
break;
default :
i++;
break;
} /* end switch */
} /* end while */
return (nchanges);
} /* end StoreOptimize */
/**********************************************************************/
