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/*
* normalsf.s
*
* Normalizes a denormalized 1.29 mantissa by left shifting it
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
* License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is Librcx floating point code, released May 27, 1999.
*
* The Initial Developer of the Original Code is Kekoa Proudfoot.
* Portions created by Kekoa Proudfoot are Copyright (C) 1999
* Kekoa Proudfoot. All Rights Reserved.
*
* Contributor(s): Kekoa Proudfoot <kekoa@graphics.stanford.edu>
*/
.section .text
;;
;; function: normalizesf
;; input: exp in r4, mant in r5r6, mant must be non-zero and in 1.29 format
;; output: exp in r4, mant in r5r6
;;
.global ___normalizesf
___normalizesf:
; Left shift while one bit not set (final format is 1.29)
while_0:
; Is one bit set? (one bit is in 1 << 29 or 20000000 position)
btst #5,r5h ; load 20000000 bit of mantissa
bne endwhile_0 ; non-zero indicates bit set
; Shift mantissa one place to left
add.w r6,r6 ; use add to shift mantissa left 1 place
addx.b r5l,r5l
addx.b r5h,r5h
; Decrement exponent
subs.w #1,r4
; Repeat
bra while_0
endwhile_0:
rts
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