lang/cem/cemcom.ansi/fltcstoper.c

   1 /*
   2  * (c) copyright 1989 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 /* $Id: fltcstoper.c,v 1.7 1994/06/27 08:00:02 ceriel Exp $ */
   6 /*      C O N S T A N T   E X P R E S S I O N   H A N D L I N G         */
   7 /*        F O R   F L O A T I N G   P O I N T   N U M B E R S           */
   8
   9 #include        "debug.h"
  10 #include        "assert.h"
  11 #include        <alloc.h>
  12 #include        "trgt_sizes.h"
  13 #include        "idf.h"
  14 #include        <flt_arith.h>
  15 #include        "arith.h"
  16 #include        "type.h"
  17 #include        "label.h"
  18 #include        "expr.h"
  19 #include        "sizes.h"
  20 #include        "Lpars.h"
  21
  22 extern int ResultKnown;
  23 extern char *symbol2str();
  24
  25 fltcstbin(expp, oper, expr)
  26         register struct expr **expp, *expr;
  27 {
  28         /*      The operation oper is performed on the constant
  29                 expressions *expp(ld) and expr(ct), and the result restored in
  30                 *expp.
  31         */
  32         flt_arith o1, o2;
  33         int compar = 0;
  34         int cmpval = 0;
  35
  36         o1 = (*expp)->FL_ARITH;
  37         o2 = expr->FL_ARITH;
  38
  39         ASSERT(is_fp_cst(*expp) && is_fp_cst(expr));
  40         switch (oper)   {
  41         case '*':
  42                 flt_mul(&o1, &o2, &o1);
  43                 break;
  44         case '/':
  45                 flt_div(&o1, &o2, &o1);
  46                 break;
  47         case '+':
  48                 flt_add(&o1, &o2, &o1);
  49                 break;
  50         case '-':
  51                 flt_sub(&o1, &o2, &o1);
  52                 break;
  53         case '<':
  54         case '>':
  55         case LESSEQ:
  56         case GREATEREQ:
  57         case EQUAL:
  58         case NOTEQUAL:
  59                 compar++;
  60                 cmpval = flt_cmp(&o1, &o2);
  61                 switch(oper) {
  62                 case '<':       cmpval = (cmpval < 0);  break;
  63                 case '>':       cmpval = (cmpval > 0);  break;
  64                 case LESSEQ:    cmpval = (cmpval <= 0); break;
  65                 case GREATEREQ: cmpval = (cmpval >= 0); break;
  66                 case EQUAL:     cmpval = (cmpval == 0); break;
  67                 case NOTEQUAL:  cmpval = (cmpval != 0); break;
  68                 }
  69                 break;
  70         default:
  71                 /* in case of situations like a += 3.0; where a undefined */
  72                 flt_status = 0;
  73                 break;
  74         }
  75
  76         switch (flt_status) {
  77                 case 0:
  78                 case FLT_UNFL:                  /* ignore underflow */
  79                         break;
  80                 case FLT_OVFL:
  81                         if (!ResultKnown)
  82                             expr_warning(expr,"floating point overflow on %s"
  83                                         , symbol2str(oper));
  84                         break;
  85                 case FLT_DIV0:
  86                         if (!ResultKnown)
  87                                 expr_error(expr,"division by 0.0");
  88                         else
  89                                 expr_warning(expr,"division by 0.0");
  90                         break;
  91                 default:        /* there can't be another status */
  92                         crash("(fltcstoper) bad status");
  93         }
  94         if (compar) {
  95                 fill_int_expr(*expp, (arith)cmpval, INT);
  96         } else {
  97                 (*expp)->FL_ARITH = o1;
  98         }
  99         (*expp)->ex_flags |= expr->ex_flags;
 100         (*expp)->ex_flags &= ~EX_PARENS;
 101         free_expression(expr);
 102 }