head     56.1;
access   ;
symbols  ;
locks    ; strict;
comment  @# @;


56.1
date     91.11.05.09.33.47;  author jwh;  state Exp;
branches ;
next     55.1;

55.1
date     91.08.25.10.12.07;  author jwh;  state Exp;
branches ;
next     54.2;

54.2
date     91.08.21.14.39.09;  author jwh;  state Exp;
branches ;
next     54.1;

54.1
date     91.03.18.15.19.10;  author jwh;  state Exp;
branches ;
next     53.1;

53.1
date     91.03.11.19.20.18;  author jwh;  state Exp;
branches ;
next     52.1;

52.1
date     91.02.19.09.04.43;  author jwh;  state Exp;
branches ;
next     51.2;

51.2
date     91.02.10.16.35.44;  author jwh;  state Exp;
branches ;
next     51.1;

51.1
date     91.01.30.16.03.55;  author jwh;  state Exp;
branches ;
next     1.1;

1.1
date     91.01.16.16.19.34;  author jwh;  state Exp;
branches ;
next     ;


desc
@first version.
@


56.1
log
@Automatic bump of revision number for PWS version 3.25
@
text
@@


55.1
log
@Automatic bump of revision number for PWS version 3.25A
@
text
@@


54.2
log
@
pws2rcs automatic delta on Wed Aug 21 13:42:03 MDT 1991
@
text
@@


54.1
log
@Automatic bump of revision number for PWS version 3.24
@
text
@a0 139
*
*       sgetem.sa 3.1 12/10/90
*
*       The entry point sGETEXP returns the exponent portion
*       of the input argument.  The exponent bias is removed
*       and the exponent value is returned as an extended
*       precision number in fp0.  sGETEXPD handles denormalized
*       numbers.
*
*       The entry point sGETMAN extracts the mantissa of the
*       input argument.  The mantissa is converted to an
*       extended precision number and returned in fp0.  The
*       range of the result is [1.0 - 2.0).
*
*
*       Input:  Double-extended number X in the ETEMP space in
*               the floating-point save stack.
*
*       Output: The functions return exp(X) or man(X) in fp0.
*
*       Modified: fp0.
*
*
*               Copyright (C) Motorola, Inc. 1990
*                       All Rights Reserved
*
*       THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
*       The copyright notice above does not evidence any
*       actual or intended publication of such source code.



	include fpsp_h

	refr    nrm_set

*
* This entry point is used by the unimplemented instruction exception
* handler.  It points a0 to the input operand.
*
*
*
*       SGETEXP
*

	def     sgetexp
sgetexp    equ    *
	move.w  LOCAL_EX(a0),d0 ;get the exponent
	bclr    #15,d0          ;clear the sign bit
	sub.w   #$3fff,d0       ;subtract off the bias
	fmove.w  d0,fp0         ;move the exp to fp0
	rts

	def     sgetexpd
sgetexpd    equ    *
	bclr    #sign_bit,LOCAL_EX(a0)
	bsr     nrm_set         ;normalize (exp will go negative)
	move.w  LOCAL_EX(a0),d0 ;load resulting exponent into d0
	sub.w   #$3fff,d0       ;subtract off the bias
	fmove.w d0,fp0          ;move the exp to fp0
	rts
*
*
* This entry point is used by the unimplemented instruction exception
* handler.  It points a0 to the input operand.
*
*
*
*       SGETMAN
*
*
* For normalized numbers, leave the mantissa alone, simply load
* with an exponent of +/- $3fff.
*
	def     sgetman
sgetman    equ    *
	move.l  USER_FPCONTROL(a6),d0
	andi.l  #$ffffff00,d0   ;clear rounding precision and mode
	fmove.l d0,FPCONTROL            ;this FPCONTROL setting is used by the 882
	move.w  LOCAL_EX(a0),d0 ;get the exp (really just want sign bit)
	or.w    #$7fff,d0       ;clear old exp
	bclr    #14,d0          ;make it the new exp +-3fff
	move.w  d0,LOCAL_EX(a0) ;move the sign & exp back to fsave stack
	fmove.x (a0),fp0        ;put new value back in fp0
	rts

*
* For denormalized numbers, shift the mantissa until the j-bit = 1,
* then load the exponent with +/1 $3fff.
*
	def     sgetmand
sgetmand    equ    *
	move.l  LOCAL_HI(a0),d0 ;load ms mant in d0
	move.l  LOCAL_LO(a0),d1 ;load ls mant in d1
	bsr     shft            ;shift mantissa bits till msbit is set
	move.l  d0,LOCAL_HI(a0) ;put ms mant back on stack
	move.l  d1,LOCAL_LO(a0) ;put ls mant back on stack
	bra.b   sgetman

*
*       SHFT
*
*       Shifts the mantissa bits until msbit is set.
*       input:
*               ms mantissa part in d0
*               ls mantissa part in d1
*       output:
*               shifted bits in d0 and d1
shft    equ    *
	tst.l   d0              ;if any bits set in ms mant
	bne.b   upper           ;then branch
*                               ;else no bits set in ms mant
	tst.l   d1              ;test if any bits set in ls mant
	bne.b   cont            ;if set then continue
	bra.b   shft_end        ;else return
cont    equ    *
	move.l  d3,-(a7)        ;save d3
	exg     d0,d1           ;shift ls mant to ms mant
	bfffo   d0{0:32},d3     ;find first 1 in ls mant to d0
	lsl.l   d3,d0           ;shift first 1 to integer bit in ms mant
	move.l  (a7)+,d3        ;restore d3
	bra.b   shft_end
upper    equ    *

	movem.l d3/d5/d6,-(a7)  ;save registers
	bfffo   d0{0:32},d3     ;find first 1 in ls mant to d0
	lsl.l   d3,d0           ;shift ms mant until j-bit is set
	move.l  d1,d6           ;save ls mant in d6
	lsl.l   d3,d1           ;shift ls mant by count
	move.l  #32,d5
	sub.l   d3,d5           ;sub 32 from shift for ls mant
	lsr.l   d5,d6           ;shift off all bits but those that will
*                               ;be shifted into ms mant
	or.l    d6,d0           ;shift the ls mant bits into the ms mant
	movem.l (a7)+,d3/d5/d6  ;restore registers
shft_end    equ    *
	rts

	end
@


53.1
log
@Automatic bump of revision number for PWS version 3.24B
@
text
@@


52.1
log
@Automatic bump of revision number for PWS version 3.24A
@
text
@@


51.2
log
@*** empty log message ***
@
text
@@


51.1
log
@Automatic bump of revision number for PWS version 3.24d
@
text
@d33 1
a33 1
	include fpsp.h
@


1.1
log
@Initial revision
@
text
@@
