diff options
Diffstat (limited to 'usr.bin/f2c/cds.c')
| -rw-r--r-- | usr.bin/f2c/cds.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/usr.bin/f2c/cds.c b/usr.bin/f2c/cds.c new file mode 100644 index 0000000..3a9a9dc --- /dev/null +++ b/usr.bin/f2c/cds.c @@ -0,0 +1,190 @@ +/**************************************************************** +Copyright 1990, 1993 by AT&T Bell Laboratories and Bellcore. + +Permission to use, copy, modify, and distribute this software +and its documentation for any purpose and without fee is hereby +granted, provided that the above copyright notice appear in all +copies and that both that the copyright notice and this +permission notice and warranty disclaimer appear in supporting +documentation, and that the names of AT&T Bell Laboratories or +Bellcore or any of their entities not be used in advertising or +publicity pertaining to distribution of the software without +specific, written prior permission. + +AT&T and Bellcore disclaim all warranties with regard to this +software, including all implied warranties of merchantability +and fitness. In no event shall AT&T or Bellcore be liable for +any special, indirect or consequential damages or any damages +whatsoever resulting from loss of use, data or profits, whether +in an action of contract, negligence or other tortious action, +arising out of or in connection with the use or performance of +this software. +****************************************************************/ + +/* Put strings representing decimal floating-point numbers + * into canonical form: always have a decimal point or + * exponent field; if using an exponent field, have the + * number before it start with a digit and decimal point + * (if the number has more than one digit); only have an + * exponent field if it saves space. + * + * Arrange that the return value, rv, satisfies rv[0] == '-' || rv[-1] == '-' . + */ + +#include "sysdep.h" + + char * +cds(s, z0) + char *s, *z0; +{ + int ea, esign, et, i, k, nd = 0, sign = 0, tz; + char c, *z; + char ebuf[24]; + long ex = 0; + static char etype[Table_size], *db; + static int dblen = 64; + + if (!db) { + etype['E'] = 1; + etype['e'] = 1; + etype['D'] = 1; + etype['d'] = 1; + etype['+'] = 2; + etype['-'] = 3; + db = Alloc(dblen); + } + + while((c = *s++) == '0'); + if (c == '-') + { sign = 1; c = *s++; } + else if (c == '+') + c = *s++; + k = strlen(s) + 2; + if (k >= dblen) { + do dblen <<= 1; + while(k >= dblen); + free(db); + db = Alloc(dblen); + } + if (etype[(unsigned char)c] >= 2) + while(c == '0') c = *s++; + tz = 0; + while(c >= '0' && c <= '9') { + if (c == '0') + tz++; + else { + if (nd) + for(; tz; --tz) + db[nd++] = '0'; + else + tz = 0; + db[nd++] = c; + } + c = *s++; + } + ea = -tz; + if (c == '.') { + while((c = *s++) >= '0' && c <= '9') { + if (c == '0') + tz++; + else { + if (tz) { + ea += tz; + if (nd) + for(; tz; --tz) + db[nd++] = '0'; + else + tz = 0; + } + db[nd++] = c; + ea++; + } + } + } + if (et = etype[(unsigned char)c]) { + esign = et == 3; + c = *s++; + if (et == 1) { + if(etype[(unsigned char)c] > 1) { + if (c == '-') + esign = 1; + c = *s++; + } + } + while(c >= '0' && c <= '9') { + ex = 10*ex + (c - '0'); + c = *s++; + } + if (esign) + ex = -ex; + } + switch(c) { + case 0: + break; +#ifndef VAX + case 'i': + case 'I': + Fatal("Overflow evaluating constant expression."); + case 'n': + case 'N': + Fatal("Constant expression yields NaN."); +#endif + default: + Fatal("unexpected character in cds."); + } + ex -= ea; + if (!nd) { + if (!z0) + z0 = mem(4,0); + strcpy(z0, "-0."); + sign = 0; + } + else if (ex > 2 || ex + nd < -2) { + sprintf(ebuf, "%ld", ex + nd - 1); + k = strlen(ebuf) + nd + 3; + if (nd > 1) + k++; + if (!z0) + z0 = mem(k,0); + z = z0; + *z++ = '-'; + *z++ = *db; + if (nd > 1) { + *z++ = '.'; + for(k = 1; k < nd; k++) + *z++ = db[k]; + } + *z++ = 'e'; + strcpy(z, ebuf); + } + else { + k = (int)(ex + nd); + i = nd + 3; + if (k < 0) + i -= k; + else if (ex > 0) + i += ex; + if (!z0) + z0 = mem(i,0); + z = z0; + *z++ = '-'; + if (ex >= 0) { + for(k = 0; k < nd; k++) + *z++ = db[k]; + while(--ex >= 0) + *z++ = '0'; + *z++ = '.'; + } + else { + for(i = 0; i < k;) + *z++ = db[i++]; + *z++ = '.'; + while(++k <= 0) + *z++ = '0'; + while(i < nd) + *z++ = db[i++]; + } + *z = 0; + } + return sign ? z0 : z0+1; + } |
