/* * Copyright (c) 1986 Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Computer Consoles Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #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) * double value, *iptr; * * Modf returns the fractional part of "value", * and stores the integer part indirectly through "iptr". */ #include <tahoemath/fp.h> #include "DEFS.h" ENTRY(modf, R2|R3|R4|R5) /* * Some initializations: */ 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 */ std r2 ldd 4(fp) /* isolate the fraction */ subd r2 std r0 movl 12(fp),r6 /* get int return address */ movl r2,(r6) movl r3,4(r6) ret gsb: clrl r3 movl 4(fp),r0 /* fetch operand to r0,r1. */ movl 8(fp),r1 movl 12(fp),r6 /* fetch addr of int to r6. */ /* * get exponent */ andl3 $EXPMASK,r0,r2 /* r2 will hold the exponent. */ jeql is_reserved /* check for reserved operand. */ shrl $EXPSHIFT,r2,r2 subl2 $BIAS,r2 /* unbias it. */ jleq allfrac /* it's int part is zero. */ cmpl r2,$56 jgeq allint /* it's fraction part is zero. */ /* * get fraction */ movl r0,r4 /* remember the original number. */ movl r1,r5 bbc $31,r0,positive /* if negative remember it. */ incl r3 positive: /* clear the non fraction parts. */ andl2 $(0!(EXPMASK | SIGNBIT)),r0 /* add the hidden bit. */ orl2 $(0!CLEARHID),r0 cmpl r2,$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. */ 1: andl2 r8,r0 /* clear int. bits from fraction part. */ shar $1,r8,r8 aoblss $0,r7,1b 1: andl2 r8,r4 /* clear frac bits for int calculation: */ shar $1,r8,r8 cmpl $0xffffffff,r8 jneq 1b clrl r5 jmp norm onlyallr0: clrl r0 clrl r5 jmp norm in_r1: clrl r0 /* clear int part for frac. calculation. */ subl3 r2,$HID_POS,r7 movl $0x7fffffff,r8 1: andl2 r8,r1 shar $1,r8,r8 orl2 $0x80000000,r8 /* force the 'sign' bit to be on. */ aoblss $0,r7,1b 1: andl2 r8,r5 shar $1,r8,r8 cmpl $0xffffffff,r8 jneq 1b norm: addl2 $BIAS,r2 /* fnorm expects it biased. */ callf $4,fnorm /* normelize fraction part. */ cmpl $0,r0 jeql 1f bbc $0,r3,1f orl2 $0x80000000,r0 1: movl r4,(r6) /* put int part in place. */ movl r5,4(r6) ret allint: movl r0,(r6) /* copy the argument to the int addr. */ movl r1,4(r6) clrl r0 /* clear the fraction part. */ clrl r1 ret allfrac: /* the fraction is ready in r0,r1. */ clrl (r6) /* zero the int part. */ clrl 4(r6) ret ret_zero: clrl (r6) clrl 4(r6) clrl r0 clrl r1 ret is_reserved: bbc $31,r0,ret_zero callf $4,fpresop ret