diff options
Diffstat (limited to 'misc/pascal/insn32/plopt/pcopt.c')
| -rw-r--r-- | misc/pascal/insn32/plopt/pcopt.c | 839 |
1 files changed, 839 insertions, 0 deletions
diff --git a/misc/pascal/insn32/plopt/pcopt.c b/misc/pascal/insn32/plopt/pcopt.c new file mode 100644 index 000000000..ee5f4d924 --- /dev/null +++ b/misc/pascal/insn32/plopt/pcopt.c @@ -0,0 +1,839 @@ +/**********************************************************************
+ * pcopt.c
+ * Constant Expression Optimizations
+ *
+ * Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ * Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <stdio.h>
+
+#include "keywords.h"
+#include "pdefs.h"
+#include "pinsn32.h"
+
+#include "paslib.h"
+#include "popt.h"
+#include "polocal.h"
+#include "pcopt.h"
+
+/**********************************************************************/
+
+int unaryOptimize(void)
+{
+ register uint32 temp;
+ register int i;
+ int nchanges = 0;
+
+ TRACE(stderr, "[unaryOptimize]");
+
+ /* At least two pcodes are need to perform unary optimizations */
+
+ i = 0;
+ while (i < nops-1)
+ {
+ /* Check for a constant value being pushed onto the stack */
+
+ if (GETOP(pptr[i]) == oPUSH)
+ {
+ switch (GETOP(pptr[i+1]))
+ {
+ /* Delete unary operators on constants */
+ case oNEG :
+ PUTARG(pptr[i], -GETARG(pptr[i]));
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oABS :
+ if ((sint32)GETARG(pptr[i]) < 0)
+ PUTARG(pptr[i], -(sint32)GETARG(pptr[i]));
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oINC :
+ PUTARG(pptr[i], GETARG(pptr[i]) + 1);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oDEC :
+ PUTARG(pptr[i], GETARG(pptr[i]) - 1);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oNOT :
+ PUTARG(pptr[i], ~GETARG(pptr[i]));
+ PUTARG(pptr[i], ~(GETARG(pptr[i])));
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ /* Simplify binary operations on constants */
+
+ case oADD :
+ if (GETARG(pptr[i]) == 0)
+ {
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i+1], oINC);
+ deletePcode(i);
+ nchanges++;
+ } /* end else if */
+ else if (GETARG(pptr[i]) == ARGONES)
+ {
+ PUTOP(pptr[i+1], oDEC);
+ deletePcode(i);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oSUB :
+ if (GETARG(pptr[i]) == 0)
+ {
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i+1], oDEC);
+ deletePcode(i);
+ nchanges++;
+ } /* end else if */
+ else if (GETARG(pptr[i]) == ARGONES)
+ {
+ PUTOP(pptr[i+1], oINC);
+ deletePcode(i);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oMUL :
+ case oDIV :
+ temp = 0;
+ switch (GETARG(pptr[i]))
+ {
+ case 1 :
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+ case 16384 : temp++;
+ case 8192 : temp++;
+ case 4096 : temp++;
+ case 2048 : temp++;
+ case 1024 : temp++;
+ case 512 : temp++;
+ case 256 : temp++;
+ case 128 : temp++;
+ case 64 : temp++;
+ case 32 : temp++;
+ case 16 : temp++;
+ case 8 : temp++;
+ case 4 : temp++;
+ case 2 : temp++;
+ PUTARG(pptr[i], temp);
+ if (GETOP(pptr[i+1]) == oMUL)
+ PUTOP(pptr[i+1], oSLL);
+ else
+ PUTOP(pptr[i+1], oSRA);
+ nchanges++;
+ i++;
+ break;
+
+ default :
+ i++;
+ break;
+ } /* end switch */
+ break;
+
+ case oSLL :
+ case oSRL :
+ case oSRA :
+ case oOR :
+ if (GETARG(pptr[i]) == 0)
+ {
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oAND :
+ if (GETARG(pptr[i]) == ARGONES)
+ {
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ /* Delete comparisons of constants to zero */
+
+ case oEQUZ :
+ if (GETARG(pptr[i]) == 0)
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oNEQZ :
+ if (GETARG(pptr[i]) != 0)
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oLTZ :
+ if ((sint32)GETARG(pptr[i]) < 0)
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oGTEZ :
+ if ((sint32)GETARG(pptr[i]) >= 0)
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oGTZ :
+ if (GETARG(pptr[i]) > 0)
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ case oLTEZ :
+ if (GETARG(pptr[i]) <= 0)
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcode(i+1);
+ nchanges++;
+ break;
+
+ /* Simplify comparisons with certain constants */
+
+ case oEQU :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1],oEQUZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i], oDEC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oEQUZ);
+ nchanges++;
+ } /* end else if */
+ else if ((sint32)GETARG(pptr[i]) == -1)
+ {
+ PUTOP(pptr[i], oINC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oEQUZ);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oNEQ :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1], oNEQZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i], oDEC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oNEQZ);
+ nchanges++;
+ } /* end else if */
+ else if ((sint32)GETARG(pptr[i]) == -1)
+ {
+ PUTOP(pptr[i], oINC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oNEQZ);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oLT :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1], oLTZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i], oDEC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oLTZ);
+ nchanges++;
+ } /* end else if */
+ else if ((sint32)GETARG(pptr[i]) == -1)
+ {
+ PUTOP(pptr[i], oINC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oLTZ);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oGTE :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1], oGTEZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i], oDEC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oGTEZ);
+ nchanges++;
+ } /* end else if */
+ else if ((sint32)GETARG(pptr[i]) == -1)
+ {
+ PUTOP(pptr[i], oINC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oGTEZ);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oGT :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1], oGTZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i], oDEC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oGTZ);
+ nchanges++;
+ } /* end else if */
+ else if ((sint32)GETARG(pptr[i]) == -1)
+ {
+ PUTOP(pptr[i], oINC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oGTZ);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oLTE :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1], oLTEZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i], oDEC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oLTEZ);
+ nchanges++;
+ } /* end else if */
+ else if ((sint32)GETARG(pptr[i]) == -1)
+ {
+ PUTOP(pptr[i], oINC);
+ PUTARG(pptr[i], 0);
+ PUTOP(pptr[i+1], oLTEZ);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ /* Simplify or delete condition branches on constants */
+
+ case oJEQUZ :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+1], oJMP);
+ deletePcode(i);
+ } /* end if */
+ else
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+
+ case oJNEQZ :
+ if (GETARG(pptr[i]) != 0)
+ {
+ PUTOP(pptr[i+1], oJMP);
+ deletePcode(i);
+ } /* end if */
+ else
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+
+ case oJLTZ :
+ if ((sint32)GETARG(pptr[i]) < 0)
+ {
+ PUTOP(pptr[i+1], oJMP);
+ deletePcode(i);
+ } /* end if */
+ else
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+
+ case oJGTEZ :
+ if ((sint32)GETARG(pptr[i]) >= 0)
+ {
+ PUTOP(pptr[i+1], oJMP);
+ deletePcode(i);
+ } /* end if */
+ else
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+
+ case oJGTZ :
+ if (GETARG(pptr[i]) > 0)
+ {
+ PUTOP(pptr[i+1], oJMP);
+ deletePcode(i);
+ } /* end if */
+ else
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+
+ case oJLTEZ :
+ if (GETARG(pptr[i]) <= 0)
+ {
+ PUTOP(pptr[i+1], oJMP);
+ deletePcode(i);
+ } /* end if */
+ else
+ deletePcodePair(i, (i+1));
+ nchanges++;
+ break;
+
+ default :
+ i++;
+ break;
+ } /* end switch */
+ } /* end if */
+
+ /* Delete multiple modifications of DSEG pointer */
+
+ else if (GETOP(pptr[i]) == oINDS)
+ {
+ if (GETOP(pptr[i+1]) == oINDS)
+ {
+ PUTARG(pptr[i], GETARG(pptr[i] + GETARG(pptr[i+1])));
+ deletePcode(i+1);
+ } /* end if */
+ else i++;
+ } /* end else if */
+ else i++;
+ } /* end while */
+
+ return (nchanges);
+
+} /* end unaryOptimize */
+
+/**********************************************************************/
+
+int binaryOptimize(void)
+{
+ register int i;
+ int nchanges = 0;
+
+ TRACE(stderr, "[binaryOptimize]");
+
+ /* At least two pcodes are needed to perform the following binary */
+ /* operator optimizations */
+
+ i = 0;
+ while (i < nops-2)
+ {
+ if (GETOP(pptr[i]) == oPUSH)
+ {
+ if (GETOP(pptr[i+1]) == oPUSH)
+ {
+ switch (GETOP(pptr[i+2]))
+ {
+ case oADD :
+ PUTARG(pptr[i], GETARG(pptr[i]) + GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oSUB :
+ PUTARG(pptr[i], GETARG(pptr[i]) - GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oMUL :
+ PUTARG(pptr[i], GETARG(pptr[i]) * GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oDIV :
+ PUTARG(pptr[i], GETARG(pptr[i]) / (sint32)GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oMOD :
+ PUTARG(pptr[i], GETARG(pptr[i]) % GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oSLL :
+ PUTARG(pptr[i], GETARG(pptr[i]) << GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oSRL :
+ PUTARG(pptr[i], GETARG(pptr[i]) >> GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oSRA :
+ PUTARG(pptr[i], (sint32)GETARG(pptr[i]) >> GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oOR :
+ PUTARG(pptr[i], GETARG(pptr[i]) | GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oAND :
+ PUTARG(pptr[i], GETARG(pptr[i]) & GETARG(pptr[i+1]));
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oEQU :
+ if (GETARG(pptr[i]) == GETARG(pptr[i+1]))
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oNEQ :
+ if (GETARG(pptr[i]) != GETARG(pptr[i+1]))
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oLT :
+ if ((sint32)GETARG(pptr[i]) < (sint32)GETARG(pptr[i+1]))
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oGTE :
+ if ((sint32)GETARG(pptr[i]) >= (sint32)GETARG(pptr[i+1]))
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oGT :
+ if ((sint32)GETARG(pptr[i]) > (sint32)GETARG(pptr[i+1]))
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ case oLTE :
+ if ((sint32)GETARG(pptr[i]) <= (sint32)GETARG(pptr[i+1]))
+ PUTARG(pptr[i], -1);
+ else
+ PUTARG(pptr[i], 0);
+ deletePcodePair((i+1), (i+2));
+ nchanges++;
+ break;
+
+ default :
+ i++;
+ break;
+ } /* end switch */
+ } /* end if */
+
+ /* A single (constant) pcode is sufficient to perform the */
+ /* following binary operator optimizations */
+
+ else if ((GETOP(pptr[i+1]) == oLDSH) || (GETOP(pptr[i+1]) == oLDSB) ||
+ (GETOP(pptr[i+1]) == oLAS) || (GETOP(pptr[i+1]) == oLAC))
+ {
+ switch (GETOP(pptr[i+2]))
+ {
+ case oADD :
+ if (GETARG(pptr[i]) == 0)
+ {
+ deletePcodePair(i, (i+2));
+ nchanges++;
+ } /* end if */
+ else if (GETARG(pptr[i]) == 1)
+ {
+ PUTOP(pptr[i+2], oINC);
+ deletePcode(i);
+ nchanges++;
+ } /* end else if */
+ else if (GETARG(pptr[i]) == ARGONES)
+ {
+ PUTOP(pptr[i+2], oDEC);
+ deletePcode(i);
+ nchanges++;
+ } /* end else if */
+ else i++;
+ break;
+
+ case oSUB :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i], oNEG);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oMUL :
+ {
+ sint32 stmp32 = 0;
+ switch (GETARG(pptr[i]))
+ {
+ case 1 :
+ deletePcodePair(i, (i+2));
+ nchanges++;
+ break;
+ case 16384 : stmp32++;
+ case 8192 : stmp32++;
+ case 4096 : stmp32++;
+ case 2048 : stmp32++;
+ case 1024 : stmp32++;
+ case 512 : stmp32++;
+ case 256 : stmp32++;
+ case 128 : stmp32++;
+ case 64 : stmp32++;
+ case 32 : stmp32++;
+ case 16 : stmp32++;
+ case 8 : stmp32++;
+ case 4 : stmp32++;
+ case 2 : stmp32++;
+ PUTOP(pptr[i], GETOP(pptr[i+1]));
+ PUTARG(pptr[i], GETARG(pptr[i+1]));
+ PUTOP(pptr[i+1], oPUSH);
+ PUTARG(pptr[i+1], stmp32);
+ PUTOP(pptr[i+2], oSLL);
+ nchanges++;
+ i++;
+ break;
+
+ default :
+ i++;
+ break;
+ }
+ }
+ break;
+
+ case oOR :
+ if (GETARG(pptr[i]) == 0)
+ {
+ deletePcodePair(i, (i+2));
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oAND :
+ if (GETARG(pptr[i]) == ARGONES)
+ {
+ deletePcodePair(i, (i+2));
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oEQU :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+2], oEQUZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oNEQ :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+2], oNEQZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oLT :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+2], oGTEZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oGTE :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+2], oLTZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oGT :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+2], oLTEZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ case oLTE :
+ if (GETARG(pptr[i]) == 0)
+ {
+ PUTOP(pptr[i+2], oGTZ);
+ deletePcode(i);
+ nchanges++;
+ } /* end if */
+ else i++;
+ break;
+
+ default :
+ i++;
+ break;
+
+ } /* end switch */
+ } /* end else if */
+ else i++;
+ } /* end if */
+
+ /* Misc improvements on binary operators */
+
+ else if (GETOP(pptr[i]) == oNEG)
+ {
+ /* Negation followed by add is subtraction */
+
+ if (GETOP(pptr[i+1]) == oADD)
+ {
+ PUTOP(pptr[i+1], oSUB);
+ deletePcode(i);
+ nchanges++;
+ }
+
+ /* Negation followed by subtraction is addition */
+
+ else if (GETOP(pptr[i]) == oSUB)
+ {
+ PUTOP(pptr[i+1], oADD);
+ deletePcode(i);
+ nchanges++;
+ }
+ else i++;
+ }
+ else i++;
+ } /* end while */
+
+ return (nchanges);
+
+} /* end binaryOptimize */
+
+/**********************************************************************/
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