/misc/pascal/insn16/popt/plopt.c
C | 250 lines | 161 code | 31 blank | 58 comment | 45 complexity | f088f0ff3c30b18b14e57a3f7d47a81a MD5 | raw file
Possible License(s): GPL-2.0, 0BSD
- /**********************************************************************
- * 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 */
- /**********************************************************************/