From b27b34a76fa16fcb96632a5bf245f3876183c479 Mon Sep 17 00:00:00 2001 From: John Wiegley Date: Sun, 15 Apr 2007 12:55:22 +0000 Subject: Added a reference to gdtoa, for doing expected conversion of double to amount. --- gdtoa/strtordd.c | 199 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 gdtoa/strtordd.c (limited to 'gdtoa/strtordd.c') diff --git a/gdtoa/strtordd.c b/gdtoa/strtordd.c new file mode 100644 index 00000000..9c2b46e6 --- /dev/null +++ b/gdtoa/strtordd.c @@ -0,0 +1,199 @@ +/**************************************************************** + +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" + + void +#ifdef KR_headers +ULtodd(L, bits, exp, k) ULong *L; ULong *bits; Long exp; int k; +#else +ULtodd(ULong *L, ULong *bits, Long exp, int k) +#endif +{ + int i, j; + + switch(k & STRTOG_Retmask) { + case STRTOG_NoNumber: + case STRTOG_Zero: + L[0] = L[1] = L[2] = L[3] = 0; + break; + + case STRTOG_Normal: + L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL; + 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 & (ULong)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 & (ULong)0xffffffffL; + } + else { + bits[1] = bits[0] << i - 32; + bits[0] = 0; + } + } + else { + L[2] = L[3] = 0; + break; + } + L[2+_1] = bits[0]; + 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 */ + L[2] = L[3] = 0; + L[_1] = bits[0]; + L[_0] = bits[1]; + break; + + nearly_normal: + i = hi0bits(bits[3]) - 11; /* i >= 12 */ + j = 32 - i; + L[_0] = (bits[3] << i | bits[2] >> j) & 0xfffff + | 65 - i << 20; + L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL; + L[2+_0] = bits[1] & ((ULong)1L << j) - 1; + L[2+_1] = bits[0]; + break; + + partly_normal: + i = hi0bits(bits[2]) - 11; + if (i < 0) { + j = -i; + i += 32; + L[_0] = bits[2] >> j & 0xfffff | (33 + j) << 20; + L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL; + L[2+_0] = bits[1] & ((ULong)1L << j) - 1; + L[2+_1] = bits[0]; + break; + } + if (i == 0) { + L[_0] = bits[2] & 0xfffff | 33 << 20; + L[_1] = bits[1]; + L[2+_0] = 0; + L[2+_1] = bits[0]; + break; + } + j = 32 - i; + L[_0] = (bits[2] << i | bits[1] >> j) & 0xfffff + | j + 1 << 20; + L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL; + L[2+_0] = 0; + L[2+_1] = bits[0] & (1L << j) - 1; + break; + + hardly_normal: + j = 11 - hi0bits(bits[1]); + i = 32 - j; + L[_0] = bits[1] >> j & 0xfffff | j + 1 << 20; + L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL; + L[2+_0] = 0; + L[2+_1] = bits[0] & ((ULong)1L << j) - 1; + break; + + case STRTOG_Infinite: + L[_0] = L[2+_0] = 0x7ff00000; + L[_1] = L[2+_1] = 0; + break; + + case STRTOG_NaN: + L[0] = L[2] = d_QNAN0; + L[1] = L[3] = d_QNAN1; + break; + + case STRTOG_NaNbits: + L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL; + L[_0] = bits[2] >> 21 | bits[3] << 11 + | (ULong)0x7ff00000L; + L[2+_1] = bits[0]; + L[2+_0] = bits[1] | (ULong)0x7ff00000L; + } + if (k & STRTOG_Neg) { + L[_0] |= 0x80000000L; + L[2+_0] |= 0x80000000L; + } + } + + int +#ifdef KR_headers +strtordd(s, sp, rounding, dd) CONST char *s; char **sp; int rounding; double *dd; +#else +strtordd(CONST char *s, char **sp, int rounding, double *dd) +#endif +{ +#ifdef Sudden_Underflow + static FPI fpi0 = { 106, 1-1023, 2046-1023-106+1, 1, 1 }; +#else + static FPI fpi0 = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 }; +#endif + FPI *fpi, fpi1; + ULong bits[4]; + Long exp; + int k; + + fpi = &fpi0; + if (rounding != FPI_Round_near) { + fpi1 = fpi0; + fpi1.rounding = rounding; + fpi = &fpi1; + } + k = strtodg(s, sp, fpi, &exp, bits); + ULtodd((ULong*)dd, bits, exp, k); + return k; + } -- cgit v1.2.3