home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Languguage OS 2
/
Languguage OS II Version 10-94 (Knowledge Media)(1994).ISO
/
language
/
embedded
/
m68k
/
68343ffp.arc
/
IEFLOG.SA
< prev
next >
Wrap
Text File
|
1989-08-30
|
3KB
|
70 lines
TTL IEEE FORMAT EQUIVALENT LOG (IEFLOG)
***************************************
* (C) COPYRIGHT 1981 BY MOTOROLA INC. *
***************************************
*************************************************
* IEFLOG *
* FAST FLOATING POINT LOGORITHM *
* *
* INPUT: D7 - IEEE FORMAT INPUT ARGUMENT *
* *
* OUTPUT: D7 - IEEE FORMAT LOGORITHMIC RESULT *
* *
* ALL OTHER REGISTERS TOTALLY TRANSPARENT *
* *
* CONDITION CODES: *
* Z - SET IF RESULT IS ZERO *
* N - SET IF RESULT IS NEGATIVE *
* V - SET IF RESULT IS NAN (NOT-A-NUMBER)*
* (NEGATIVE OR NAN ARGUMENT) *
* C - UNDEFINED *
* X - UNDEFINED *
* *
* ALL OTHER REGISTERS TRANSPARENT *
* *
* MAXIMUM STACK USED: 54 BYTES *
* *
* NOTES: *
* 1) SEE THE MC68344 USER'S GUIDE FOR DETAILS*
* CONCERNING IEEE FORMAT NORMALIZED RANGE *
* SUPPORT LIMITATIONS. *
* 2) SPOT CHECKS SHOW RELATIVE ERRORS BOUNDED*
* BY 5 X 10**-8. *
* 2) NEGATIVE ARGUMENTS ARE ILLEGAL AND CAUSE*
* A NAN (NOT-A-NUMBER) TO BE RETURNED. *
* 3) A ZERO ARGUMENT RETURNS MINUS INFINITY. *
* *
*************************************************
PAGE
IEFLOG IDNT 1,1 IEEE FORMAT EQUIVALENT LOGORITHM
OPT PCS
SECTION 9
XDEF IEFLOG ENTRY POINT
XREF 9:FFPLOG FFP LOGORITHM ROUTINE
XREF 9:IEFSOP FRONT-END OPERAND CONVERSION ROUTINE
XREF 9:IEFTIEEE BACK-END CONVERT TO IEEE AND RETURN
XREF 9:IEFRTNAN BACK-END RETURN NAN ROUTINE
XREF 9:IEFRTOD7 RETURN ORIGINAL D7 FROM THE CALLER
XREF FFPCPYRT COPYRIGHT STUB
**************
* LOG ENTRY *
**************
IEFLOG BSR IEFSOP CONVERT THE OPERAND
BRA.S IEFNRM +0 BRANCH NORMALIZED VALUE
* INPUT ARGUMENT IS INFINITY +8
BMI IEFRTNAN RETURN A NAN FOR A NEGATIVE ARGUMENT
BRA IEFRTOD7 RETURN PLUS INFINITY AS THE RESULT
* ARGUMENT IS NORMALIZED
IEFNRM BMI IEFRTNAN RETURN A NAN IF ARGUMENT IS NEGATIVE
BSR FFPLOG CALL FAST FLOATING POINT LOG ROUTINE
BRA IEFTIEEE AND RETURN RESULT IN IEEE FORMAT
END