diff options
Diffstat (limited to 'gdtoa/strtopdd.c')
| -rw-r--r-- | gdtoa/strtopdd.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/gdtoa/strtopdd.c b/gdtoa/strtopdd.c new file mode 100644 index 00000000..9b788eec --- /dev/null +++ b/gdtoa/strtopdd.c @@ -0,0 +1,178 @@ +/**************************************************************** + +The author of this software is David M. Gay. + +Copyright (C) 1998, 2000 by Lucent Technologies +All Rights Reserved + +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 name of Lucent or any of its entities +not be used in advertising or publicity pertaining to +distribution of the software without specific, written prior +permission. + +LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, +INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. +IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES 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. + +****************************************************************/ + +/* Please send bug reports to David M. Gay (dmg at acm dot org, + * with " at " changed at "@" and " dot " changed to "."). */ + +#include "gdtoaimp.h" + + int +#ifdef KR_headers +strtopdd(s, sp, dd) CONST char *s; char **sp; double *dd; +#else +strtopdd(CONST char *s, char **sp, double *dd) +#endif +{ +#ifdef Sudden_Underflow + static FPI fpi = { 106, 1-1023, 2046-1023-106+1, 1, 1 }; +#else + static FPI fpi = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 }; +#endif + ULong bits[4]; + Long exp; + int i, j, rv; + typedef union { + double d[2]; + ULong L[4]; + } U; + U *u; + + rv = strtodg(s, sp, &fpi, &exp, bits); + u = (U*)dd; + switch(rv & STRTOG_Retmask) { + case STRTOG_NoNumber: + case STRTOG_Zero: + u->d[0] = u->d[1] = 0.; + break; + + case STRTOG_Normal: + u->L[_1] = (bits[1] >> 21 | bits[2] << 11) & 0xffffffffL; + u->L[_0] = bits[2] >> 21 | bits[3] << 11 & 0xfffff + | exp + 0x3ff + 105 << 20; + exp += 0x3ff + 52; + if (bits[1] &= 0x1fffff) { + i = hi0bits(bits[1]) - 11; + if (i >= exp) { + i = exp - 1; + exp = 0; + } + else + exp -= i; + if (i > 0) { + bits[1] = bits[1] << i | bits[0] >> 32-i; + bits[0] = bits[0] << i & 0xffffffffL; + } + } + else if (bits[0]) { + i = hi0bits(bits[0]) + 21; + if (i >= exp) { + i = exp - 1; + exp = 0; + } + else + exp -= i; + if (i < 32) { + bits[1] = bits[0] >> 32 - i; + bits[0] = bits[0] << i & 0xffffffffL; + } + else { + bits[1] = bits[0] << i - 32; + bits[0] = 0; + } + } + else { + u->L[2] = u->L[3] = 0; + break; + } + u->L[2+_1] = bits[0]; + u->L[2+_0] = bits[1] & 0xfffff | exp << 20; + break; + + case STRTOG_Denormal: + if (bits[3]) + goto nearly_normal; + if (bits[2]) + goto partly_normal; + if (bits[1] & 0xffe00000) + goto hardly_normal; + /* completely denormal */ + u->L[2] = u->L[3] = 0; + u->L[_1] = bits[0]; + u->L[_0] = bits[1]; + break; + + nearly_normal: + i = hi0bits(bits[3]) - 11; /* i >= 12 */ + j = 32 - i; + u->L[_0] = (bits[3] << i | bits[2] >> j) & 0xfffff + | 65 - i << 20; + u->L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL; + u->L[2+_0] = bits[1] & (1L << j) - 1; + u->L[2+_1] = bits[0]; + break; + + partly_normal: + i = hi0bits(bits[2]) - 11; + if (i < 0) { + j = -i; + i += 32; + u->L[_0] = bits[2] >> j & 0xfffff | (33 + j) << 20; + u->L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL; + u->L[2+_0] = bits[1] & (1L << j) - 1; + u->L[2+_1] = bits[0]; + break; + } + if (i == 0) { + u->L[_0] = bits[2] & 0xfffff | 33 << 20; + u->L[_1] = bits[1]; + u->L[2+_0] = 0; + u->L[2+_1] = bits[0]; + break; + } + j = 32 - i; + u->L[_0] = (bits[2] << i | bits[1] >> j) & 0xfffff + | j + 1 << 20; + u->L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL; + u->L[2+_0] = 0; + u->L[2+_1] = bits[0] & (1L << j) - 1; + break; + + hardly_normal: + j = 11 - hi0bits(bits[1]); + i = 32 - j; + u->L[_0] = bits[1] >> j & 0xfffff | j + 1 << 20; + u->L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL; + u->L[2+_0] = 0; + u->L[2+_1] = bits[0] & (1L << j) - 1; + break; + + case STRTOG_Infinite: + u->L[_0] = u->L[2+_0] = 0x7ff00000; + u->L[_1] = u->L[2+_1] = 0; + break; + + case STRTOG_NaN: + u->L[0] = u->L[2] = d_QNAN0; + u->L[1] = u->L[3] = d_QNAN1; + } + if (rv & STRTOG_Neg) { + u->L[ _0] |= 0x80000000L; + u->L[2+_0] |= 0x80000000L; + } + return rv; + } |