diff options
Diffstat (limited to 'regress/lib/libc/cephes/etodec.c')
-rw-r--r-- | regress/lib/libc/cephes/etodec.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/regress/lib/libc/cephes/etodec.c b/regress/lib/libc/cephes/etodec.c new file mode 100644 index 00000000000..a15845efb67 --- /dev/null +++ b/regress/lib/libc/cephes/etodec.c @@ -0,0 +1,199 @@ +/* $OpenBSD: etodec.c,v 1.1 2011/07/02 18:11:01 martynas Exp $ */ + +/* + * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, 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. + */ + +#include "ehead.h" +void emovi(), emovo(), ecleaz(), eshdn8(), emdnorm(); +void todec(); +/* +; convert DEC double precision to e type +; double d; +; short e[NE]; +; dectoe( &d, e ); +*/ +void dectoe( d, e ) +unsigned short *d; +unsigned short *e; +{ +unsigned short y[NI]; +register unsigned short r, *p; + +ecleaz(y); /* start with a zero */ +p = y; /* point to our number */ +r = *d; /* get DEC exponent word */ +if( *d & (unsigned int )0x8000 ) + *p = 0xffff; /* fill in our sign */ +++p; /* bump pointer to our exponent word */ +r &= 0x7fff; /* strip the sign bit */ +if( r == 0 ) /* answer = 0 if high order DEC word = 0 */ + goto done; + + +r >>= 7; /* shift exponent word down 7 bits */ +r += EXONE - 0201; /* subtract DEC exponent offset */ + /* add our e type exponent offset */ +*p++ = r; /* to form our exponent */ + +r = *d++; /* now do the high order mantissa */ +r &= 0177; /* strip off the DEC exponent and sign bits */ +r |= 0200; /* the DEC understood high order mantissa bit */ +*p++ = r; /* put result in our high guard word */ + +*p++ = *d++; /* fill in the rest of our mantissa */ +*p++ = *d++; +*p = *d; + +eshdn8(y); /* shift our mantissa down 8 bits */ +done: +emovo( y, e ); +} + + + +/* +; convert e type to DEC double precision +; double d; +; short e[NE]; +; etodec( e, &d ); +*/ +#if 0 +static unsigned short decbit[NI] = {0,0,0,0,0,0,0200,0}; +void etodec( x, d ) +unsigned short *x, *d; +{ +unsigned short xi[NI]; +register unsigned short r; +int i, j; + +emovi( x, xi ); +*d = 0; +if( xi[0] != 0 ) + *d = 0100000; +r = xi[E]; +if( r < (EXONE - 128) ) + goto zout; +i = xi[M+4]; +if( (i & 0200) != 0 ) + { + if( (i & 0377) == 0200 ) + { + if( (i & 0400) != 0 ) + { + /* check all less significant bits */ + for( j=M+5; j<NI; j++ ) + { + if( xi[j] != 0 ) + goto yesrnd; + } + } + goto nornd; + } +yesrnd: + eaddm( decbit, xi ); + r -= enormlz(xi); + } + +nornd: + +r -= EXONE; +r += 0201; +if( r < 0 ) + { +zout: + *d++ = 0; + *d++ = 0; + *d++ = 0; + *d++ = 0; + return; + } +if( r >= 0377 ) + { + *d++ = 077777; + *d++ = -1; + *d++ = -1; + *d++ = -1; + return; + } +r &= 0377; +r <<= 7; +eshup8( xi ); +xi[M] &= 0177; +r |= xi[M]; +*d++ |= r; +*d++ = xi[M+1]; +*d++ = xi[M+2]; +*d++ = xi[M+3]; +} +#else + +extern int rndprc; + +void etodec( x, d ) +unsigned short *x, *d; +{ +unsigned short xi[NI]; +long exp; +int rndsav; + +emovi( x, xi ); +exp = (long )xi[E] - (EXONE - 0201); /* adjust exponent for offsets */ +/* round off to nearest or even */ +rndsav = rndprc; +rndprc = 56; +emdnorm( xi, 0, 0, exp, 64 ); +rndprc = rndsav; +todec( xi, d ); +} + +void todec( x, y ) +unsigned short *x, *y; +{ +unsigned short i; +unsigned short *p; + +p = x; +*y = 0; +if( *p++ ) + *y = 0100000; +i = *p++; +if( i == 0 ) + { + *y++ = 0; + *y++ = 0; + *y++ = 0; + *y++ = 0; + return; + } +if( i > 0377 ) + { + *y++ |= 077777; + *y++ = 0xffff; + *y++ = 0xffff; + *y++ = 0xffff; + return; + } +i &= 0377; +i <<= 7; +eshup8( x ); +x[M] &= 0177; +i |= x[M]; +*y++ |= i; +*y++ = x[M+1]; +*y++ = x[M+2]; +*y++ = x[M+3]; +} +#endif |