512 lines
12 KiB
C
512 lines
12 KiB
C
/* Generate code from machine description to perform peephole optimizations.
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Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#ifndef lint
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static char rcsid[] = "$Id: genpeep.c,v 1.1 1993/08/23 09:20:51 cgd Exp $";
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#endif /* not lint */
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#include <stdio.h>
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#include "config.h"
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#include "rtl.h"
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#include "obstack.h"
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static struct obstack obstack;
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struct obstack *rtl_obstack = &obstack;
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#define obstack_chunk_alloc xmalloc
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#define obstack_chunk_free free
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extern void free ();
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extern rtx read_rtx ();
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/* While tree-walking an instruction pattern, we keep a chain
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of these `struct link's to record how to get down to the
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current position. In each one, POS is the operand number,
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and if the operand is a vector VEC is the element number.
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VEC is -1 if the operand is not a vector. */
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struct link
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{
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struct link *next;
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int pos;
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int vecelt;
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};
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char *xmalloc ();
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static void match_rtx ();
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static void gen_exp ();
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static void fatal ();
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void fancy_abort ();
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static int max_opno;
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/* Number of operands used in current peephole definition. */
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static int n_operands;
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/* Peephole optimizations get insn codes just like insn patterns.
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Count them so we know the code of the define_peephole we are handling. */
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static int insn_code_number = 0;
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static void print_path ();
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static void print_code ();
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static void
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gen_peephole (peep)
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rtx peep;
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{
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int ninsns = XVECLEN (peep, 0);
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int i;
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n_operands = 0;
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printf (" insn = ins1;\n");
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#if 0
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printf (" want_jump = 0;\n");
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#endif
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for (i = 0; i < ninsns; i++)
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{
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if (i > 0)
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{
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printf (" do { insn = NEXT_INSN (insn);\n");
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printf (" if (insn == 0) goto L%d; }\n",
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insn_code_number);
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printf (" while (GET_CODE (insn) == NOTE\n");
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printf ("\t || (GET_CODE (insn) == INSN\n");
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printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n");
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printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
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printf (" if (GET_CODE (insn) == CODE_LABEL\n\
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|| GET_CODE (insn) == BARRIER)\n goto L%d;\n",
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insn_code_number);
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}
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#if 0
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printf (" if (GET_CODE (insn) == JUMP_INSN)\n");
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printf (" want_jump = JUMP_LABEL (insn);\n");
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#endif
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printf (" pat = PATTERN (insn);\n");
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/* Walk the insn's pattern, remembering at all times the path
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down to the walking point. */
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match_rtx (XVECEXP (peep, 0, i), NULL_PTR, insn_code_number);
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}
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/* We get this far if the pattern matches.
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Now test the extra condition. */
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if (XSTR (peep, 1) && XSTR (peep, 1)[0])
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printf (" if (! (%s)) goto L%d;\n",
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XSTR (peep, 1), insn_code_number);
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/* If that matches, construct new pattern and put it in the first insn.
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This new pattern will never be matched.
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It exists only so that insn-extract can get the operands back.
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So use a simple regular form: a PARALLEL containing a vector
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of all the operands. */
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printf (" PATTERN (ins1) = gen_rtx (PARALLEL, VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
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#if 0
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printf (" if (want_jump && GET_CODE (ins1) != JUMP_INSN)\n");
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printf (" {\n");
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printf (" rtx insn2 = emit_jump_insn_before (PATTERN (ins1), ins1);\n");
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printf (" delete_insn (ins1);\n");
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printf (" ins1 = ins2;\n");
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printf (" }\n");
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#endif
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/* Record this define_peephole's insn code in the insn,
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as if it had been recognized to match this. */
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printf (" INSN_CODE (ins1) = %d;\n",
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insn_code_number);
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/* Delete the remaining insns. */
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if (ninsns > 1)
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printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n");
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/* See reload1.c for insertion of NOTE which guarantees that this
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cannot be zero. */
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printf (" return NEXT_INSN (insn);\n");
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printf (" L%d:\n\n", insn_code_number);
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}
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static void
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match_rtx (x, path, fail_label)
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rtx x;
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struct link *path;
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int fail_label;
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{
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register RTX_CODE code;
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register int i;
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register int len;
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register char *fmt;
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struct link link;
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if (x == 0)
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return;
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code = GET_CODE (x);
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switch (code)
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{
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case MATCH_OPERAND:
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if (XINT (x, 0) > max_opno)
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max_opno = XINT (x, 0);
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if (XINT (x, 0) >= n_operands)
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n_operands = 1 + XINT (x, 0);
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printf (" x = ");
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print_path (path);
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printf (";\n");
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printf (" operands[%d] = x;\n", XINT (x, 0));
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if (XSTR (x, 1) && XSTR (x, 1)[0])
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printf (" if (! %s (x, %smode)) goto L%d;\n",
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XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
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return;
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case MATCH_DUP:
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case MATCH_PAR_DUP:
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printf (" x = ");
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print_path (path);
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printf (";\n");
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printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
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XINT (x, 0), fail_label);
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return;
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case MATCH_OP_DUP:
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printf (" x = ");
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print_path (path);
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printf (";\n");
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printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
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printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
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XINT (x, 0), fail_label);
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printf (" operands[%d] = x;\n", XINT (x, 0));
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link.next = path;
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link.vecelt = -1;
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for (i = 0; i < XVECLEN (x, 1); i++)
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{
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link.pos = i;
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match_rtx (XVECEXP (x, 1, i), &link, fail_label);
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}
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return;
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case MATCH_OPERATOR:
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if (XINT (x, 0) > max_opno)
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max_opno = XINT (x, 0);
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if (XINT (x, 0) >= n_operands)
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n_operands = 1 + XINT (x, 0);
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printf (" x = ");
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print_path (path);
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printf (";\n");
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printf (" operands[%d] = x;\n", XINT (x, 0));
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if (XSTR (x, 1) && XSTR (x, 1)[0])
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printf (" if (! %s (x, %smode)) goto L%d;\n",
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XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
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link.next = path;
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link.vecelt = -1;
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for (i = 0; i < XVECLEN (x, 2); i++)
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{
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link.pos = i;
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match_rtx (XVECEXP (x, 2, i), &link, fail_label);
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}
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return;
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case MATCH_PARALLEL:
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if (XINT (x, 0) > max_opno)
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max_opno = XINT (x, 0);
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if (XINT (x, 0) >= n_operands)
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n_operands = 1 + XINT (x, 0);
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printf (" x = ");
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print_path (path);
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printf (";\n");
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printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
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printf (" operands[%d] = x;\n", XINT (x, 0));
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if (XSTR (x, 1) && XSTR (x, 1)[0])
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printf (" if (! %s (x, %smode)) goto L%d;\n",
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XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
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link.next = path;
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link.pos = 0;
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for (i = 0; i < XVECLEN (x, 2); i++)
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{
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link.vecelt = i;
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match_rtx (XVECEXP (x, 2, i), &link, fail_label);
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}
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return;
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case ADDRESS:
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match_rtx (XEXP (x, 0), path, fail_label);
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return;
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}
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printf (" x = ");
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print_path (path);
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printf (";\n");
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printf (" if (GET_CODE (x) != ");
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print_code (code);
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printf (") goto L%d;\n", fail_label);
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if (GET_MODE (x) != VOIDmode)
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{
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printf (" if (GET_MODE (x) != %smode) goto L%d;\n",
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GET_MODE_NAME (GET_MODE (x)), fail_label);
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}
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link.next = path;
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link.vecelt = -1;
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fmt = GET_RTX_FORMAT (code);
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len = GET_RTX_LENGTH (code);
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for (i = 0; i < len; i++)
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{
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link.pos = i;
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if (fmt[i] == 'e' || fmt[i] == 'u')
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match_rtx (XEXP (x, i), &link, fail_label);
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else if (fmt[i] == 'E')
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{
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int j;
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printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n",
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i, XVECLEN (x, i), fail_label);
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for (j = 0; j < XVECLEN (x, i); j++)
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{
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link.vecelt = j;
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match_rtx (XVECEXP (x, i, j), &link, fail_label);
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}
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}
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else if (fmt[i] == 'i')
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{
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/* Make sure that at run time `x' is the RTX we want to test. */
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if (i != 0)
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{
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printf (" x = ");
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print_path (path);
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printf (";\n");
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}
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printf (" if (XINT (x, %d) != %d) goto L%d;\n",
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i, XINT (x, i), fail_label);
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}
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else if (fmt[i] == 'w')
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{
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/* Make sure that at run time `x' is the RTX we want to test. */
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if (i != 0)
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{
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printf (" x = ");
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print_path (path);
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printf (";\n");
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}
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#if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_INT
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printf (" if (XWINT (x, %d) != %d) goto L%d;\n",
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i, XWINT (x, i), fail_label);
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#else
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printf (" if (XWINT (x, %d) != %ld) goto L%d;\n",
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i, XWINT (x, i), fail_label);
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#endif
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}
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else if (fmt[i] == 's')
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{
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/* Make sure that at run time `x' is the RTX we want to test. */
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if (i != 0)
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{
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printf (" x = ");
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print_path (path);
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printf (";\n");
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}
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printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
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i, XSTR (x, i), fail_label);
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}
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}
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}
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/* Given a PATH, representing a path down the instruction's
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pattern from the root to a certain point, output code to
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evaluate to the rtx at that point. */
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static void
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print_path (path)
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struct link *path;
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{
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if (path == 0)
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printf ("pat");
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else if (path->vecelt >= 0)
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{
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printf ("XVECEXP (");
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print_path (path->next);
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printf (", %d, %d)", path->pos, path->vecelt);
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}
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else
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{
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printf ("XEXP (");
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print_path (path->next);
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printf (", %d)", path->pos);
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}
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}
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static void
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print_code (code)
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RTX_CODE code;
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{
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register char *p1;
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for (p1 = GET_RTX_NAME (code); *p1; p1++)
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{
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if (*p1 >= 'a' && *p1 <= 'z')
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putchar (*p1 + 'A' - 'a');
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else
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putchar (*p1);
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}
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}
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char *
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xmalloc (size)
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unsigned size;
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{
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register char *val = (char *) malloc (size);
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if (val == 0)
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fatal ("virtual memory exhausted");
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return val;
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}
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char *
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xrealloc (ptr, size)
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char *ptr;
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unsigned size;
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{
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char *result = (char *) realloc (ptr, size);
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if (!result)
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fatal ("virtual memory exhausted");
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return result;
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}
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static void
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fatal (s, a1, a2)
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char *s;
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{
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fprintf (stderr, "genpeep: ");
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fprintf (stderr, s, a1, a2);
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fprintf (stderr, "\n");
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exit (FATAL_EXIT_CODE);
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}
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/* More 'friendly' abort that prints the line and file.
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config.h can #define abort fancy_abort if you like that sort of thing. */
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void
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fancy_abort ()
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{
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fatal ("Internal gcc abort.");
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}
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int
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main (argc, argv)
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int argc;
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char **argv;
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{
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rtx desc;
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FILE *infile;
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register int c;
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max_opno = -1;
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obstack_init (rtl_obstack);
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if (argc <= 1)
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fatal ("No input file name.");
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infile = fopen (argv[1], "r");
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if (infile == 0)
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{
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perror (argv[1]);
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exit (FATAL_EXIT_CODE);
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}
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init_rtl ();
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printf ("/* Generated automatically by the program `genpeep'\n\
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from the machine description file `md'. */\n\n");
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printf ("#include \"config.h\"\n");
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printf ("#include \"rtl.h\"\n");
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printf ("#include \"regs.h\"\n");
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printf ("#include \"output.h\"\n");
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printf ("#include \"real.h\"\n\n");
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printf ("extern rtx peep_operand[];\n\n");
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printf ("#define operands peep_operand\n\n");
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printf ("rtx\npeephole (ins1)\n rtx ins1;\n{\n");
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printf (" rtx insn, x, pat;\n");
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printf (" int i;\n\n");
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/* Early out: no peepholes for insns followed by barriers. */
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printf (" if (NEXT_INSN (ins1)\n");
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printf (" && GET_CODE (NEXT_INSN (ins1)) == BARRIER)\n");
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printf (" return 0;\n\n");
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/* Read the machine description. */
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while (1)
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{
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c = read_skip_spaces (infile);
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if (c == EOF)
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break;
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ungetc (c, infile);
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desc = read_rtx (infile);
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if (GET_CODE (desc) == DEFINE_PEEPHOLE)
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{
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gen_peephole (desc);
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insn_code_number++;
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}
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if (GET_CODE (desc) == DEFINE_INSN
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|| GET_CODE (desc) == DEFINE_EXPAND
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|| GET_CODE (desc) == DEFINE_SPLIT)
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{
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insn_code_number++;
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}
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}
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printf (" return 0;\n}\n\n");
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if (max_opno == -1)
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max_opno = 1;
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printf ("rtx peep_operand[%d];\n", max_opno + 1);
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fflush (stdout);
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exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
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/* NOTREACHED */
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return 0;
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}
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