mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			134 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			134 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
| /* Implement the SELECT statement for character variables.
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|    Copyright (C) 2008-2016 Free Software Foundation, Inc.
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| 
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| This file is part of the GNU Fortran runtime library (libgfortran).
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| 
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| Libgfortran 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 3, or (at your option)
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| any later version.
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| 
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| Libgfortran 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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| 
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| Under Section 7 of GPL version 3, you are granted additional
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| permissions described in the GCC Runtime Library Exception, version
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| 3.1, as published by the Free Software Foundation.
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| 
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| You should have received a copy of the GNU General Public License and
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| a copy of the GCC Runtime Library Exception along with this program;
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| see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
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| <http://www.gnu.org/licenses/>.  */
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| 
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| #define select_string SUFFIX(select_string)
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| #define select_struct SUFFIX(select_struct)
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| #define compare_string SUFFIX(compare_string)
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| 
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| typedef struct
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| {
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|   CHARTYPE *low;
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|   gfc_charlen_type low_len;
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|   CHARTYPE *high;
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|   gfc_charlen_type high_len;
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|   int address;
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| }
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| select_struct;
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| 
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| extern int select_string (select_struct *table, int table_len,
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| 			  const CHARTYPE *selector,
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| 			  gfc_charlen_type selector_len);
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| export_proto(select_string);
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| 
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| 
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| /* select_string()-- Given a selector string and a table of
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|  * select_struct structures, return the address to jump to. */
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| 
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| int
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| select_string (select_struct *table, int table_len, const CHARTYPE *selector,
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| 	       gfc_charlen_type selector_len)
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| {
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|   select_struct *t;
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|   int i, low, high, mid;
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|   int default_jump = -1;
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| 
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|   if (table_len == 0)
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|     return -1;
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| 
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|   /* Record the default address if present */
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| 
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|   if (table->low == NULL && table->high == NULL)
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|     {
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|       default_jump = table->address;
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| 
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|       table++;
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|       table_len--;
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|       if (table_len == 0)
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|         return default_jump;
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|     }
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| 
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|   /* Try the high and low bounds if present. */
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| 
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|   if (table->low == NULL)
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|     {
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|       if (compare_string (table->high_len, table->high,
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| 			  selector_len, selector) >= 0)
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|         return table->address;
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| 
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|       table++;
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|       table_len--;
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|       if (table_len == 0)
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|         return default_jump;
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|     }
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| 
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|   t = table + table_len - 1;
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| 
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|   if (t->high == NULL)
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|     {
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|       if (compare_string (t->low_len, t->low, selector_len, selector) <= 0)
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|         return t->address;
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| 
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|       table_len--;
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|       if (table_len == 0)
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|         return default_jump;
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|     }
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| 
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|   /* At this point, the only table entries are bounded entries.  Find
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|      the right entry with a binary chop. */
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| 
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|   low = -1;
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|   high = table_len;
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| 
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|   while (low + 1 < high)
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|     {
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|       mid = (low + high) / 2;
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| 
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|       t = table + mid;
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|       i = compare_string (t->low_len, t->low, selector_len, selector);
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| 
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|       if (i == 0)
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|         return t->address;
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| 
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|       if (i < 0)
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|         low = mid;
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|       else
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|         high = mid;
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|     }
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| 
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|   /* The string now lies between the low indeces of the now-adjacent
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|      high and low entries.  Because it is less than the low entry of
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|      'high', it can't be that one.  If low is still -1, then no
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|      entries match.  Otherwise, we have to check the high entry of
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|      'low'. */
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| 
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|   if (low == -1)
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|     return default_jump;
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| 
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|   t = table + low;
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|   if (compare_string (selector_len, selector, t->high_len, t->high) <= 0)
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|     return t->address;
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| 
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|   return default_jump;
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| }
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