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* @(#)Kaddf.s 7.1 (Berkeley) 12/6/90
#include "../tahoe/SYS.h"
* _Kaddf(acc_most,acc_least,op_most,op_least,hfs)
ENTRY(Kaddf, R10|R9|R8|R7|R6|R5|R4|R3|R2)
* see which operand has a greater exponent
* The greater one will be fetched into r0,r1,r2,r3.
* r0,r1 - 'pure' fraction, r2 - exponent, r3 - sign).
* The smaller operand will be fetched into r4,r5,r6,r7.
tstl 4(fp) # handle (a+b) where a and/or b = 0.0
movl 12(fp),r0 # bigger operand to r0,r1
movl 4(fp),r4 # smaller operand to r4,r5
movl 4(fp),r0 # bigger operand to r0,r1
movl 12(fp),r4 # smaller operand to r4,r5
andl3 $EXPMASK,r0,r2 # r2 will hold the exponent.
andl3 $EXPMASK,r4,r6 # r6 will hold the exponent.
ret # return the bigger number.
bbc $31,r0,sign2 # if negative remember it.
bbc $31,r4,frac # if negative remember it.
#compute 'pure' fraction:
# clear the non fraction parts.
andl2 $(0!(EXPMASK | SIGNBIT)),r0
# clear the non fraction parts.
andl2 $(0!(EXPMASK | SIGNBIT)),r4
#shift the smaller operand:
clrl r9 # r9 - carry flag.
incl r9 # remember the carry.
clrl r10 # to remember the sign of the result.
jgeq norm # if positive go to normelize.
incl r10 # else remember it and negate the result.
clrl r9 # r9 - carry flag.
incl r9 # remember the carry.
norm: pushl 20(fp) # addr of returnen exception.
clrl r9 # r9 - carry flag.
incl r9 # remember the carry.
movl r4,r0 # return the smaller operand.