redo include files for kernel reorg

[unix-history] / usr / src / sys / tahoe / math / Kmodf.s

/*      Kmodf.s 1.4     90/12/04        */

#include "../tahoe/SYS.h"
#include "../math/fp.h"

/* 
*  float Kmodf (value, iptr, hfs)
*  float value, *iptr;
*  int hfs;
* 
*  Modf returns the fractional part of "value",
*  and stores the integer part indirectly through "iptr".
*/ 
       .text
ENTRY(Kmodf, R8|R7|R6|R5|R4|R3|R2)
/*
* Some initializations:
*/
       clrl    r3
       movl    4(fp),r0        /* fetch operand to r0. */
       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. */
       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 */
       jgtr    in_r1           /* some bytes in r1     */
       jeql    onlyallr0       /* all r0 must be cleared. */
       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
       subl3   r2,$HID_POS,r7
       movl    $0x7fffffff,r8
1:
       andl2   r8,r1
       shar    $1,r8,r8
       orl2    $0x80000000,r8
       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. */
       pushl   16(fp)          /* hfs */
       callf   $8,_Kfnorm      /* 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. */
       clrl    (r6)            /* zero the int part. */
       clrl    4(r6)
       ret

ret_zero:
       clrl    (r6)
       clrl    4(r6)   
       clrl    r0
       clrl    r1
       ret