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#if defined(SYSLIBC_SCCS) && !defined(lint)
.asciz "@(#)modf.s 1.3 (Berkeley) 6/1/90"
#endif /* SYSLIBC_SCCS and not lint */
* double modf (value, iptr)
* Modf returns the fractional part of "value",
* and stores the integer part indirectly through "iptr".
#include <tahoemath/fp.h>
ldd 4(fp) /* load accumulator, for converison */
cvdl r2 /* to an integer. */
bvs gsb /* iff too big grunt it out */
cvld r2 /* float the integer part */
ldd 4(fp) /* isolate the fraction */
movl 12(fp),r6 /* get int return address */
movl 4(fp),r0 /* fetch operand to r0,r1. */
movl 12(fp),r6 /* fetch addr of int to r6. */
andl3 $EXPMASK,r0,r2 /* r2 will hold the exponent. */
jeql is_reserved /* check for reserved operand. */
subl2 $BIAS,r2 /* unbias it. */
jleq allfrac /* it's int part is zero. */
jgeq allint /* it's fraction part is zero. */
movl r0,r4 /* remember the original number. */
bbc $31,r0,positive /* if negative remember it. */
/* clear the non fraction parts. */
andl2 $(0!(EXPMASK | SIGNBIT)),r0
/* add the hidden bit. */
cmpl r2,$HID_POS /* see if there are bits to clear only in r0 */
/* or r1 has to be taken care of. */
/* ( for fraction calculation) */
jgtr in_r1 /* some bytes in r1. */
jeql onlyallr0 /* all r0 must be cleared,r1 unchanged. */
/* only r0 must be canged. */
mnegl r2,r7 /* r7 - loop counter. */
movl $CLEARHID,r8 /* first bit to clear. */
andl2 r8,r0 /* clear int. bits from fraction part. */
andl2 r8,r4 /* clear frac bits for int calculation: */
clrl r0 /* clear int part for frac. calculation. */
orl2 $0x80000000,r8 /* force the 'sign' bit to be on. */
addl2 $BIAS,r2 /* fnorm expects it biased. */
callf $4,fnorm /* normelize fraction part. */
movl r4,(r6) /* put int part in place. */
movl r0,(r6) /* copy the argument to the int addr. */
clrl r0 /* clear the fraction part. */
/* the fraction is ready in r0,r1. */
clrl (r6) /* zero the int part. */