linux/arch/arm/lib/muldi3.S
Russell King 3c8fdae78c [ARM] Fix muldi3.S
When shifting the low-parts of signed numbers, a logical shift
should be used to avoid sign-extending a bit which isn't a sign
bit.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-08 17:25:33 +00:00

46 lines
857 B
ArmAsm

/*
* linux/arch/arm/lib/muldi3.S
*
* Author: Nicolas Pitre
* Created: Oct 19, 2005
* Copyright: Monta Vista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#ifdef __ARMEB__
#define xh r0
#define xl r1
#define yh r2
#define yl r3
#else
#define xl r0
#define xh r1
#define yl r2
#define yh r3
#endif
ENTRY(__muldi3)
ENTRY(__aeabi_lmul)
mul xh, yl, xh
mla xh, xl, yh, xh
mov ip, xl, lsr #16
mov yh, yl, lsr #16
bic xl, xl, ip, lsl #16
bic yl, yl, yh, lsl #16
mla xh, yh, ip, xh
mul yh, xl, yh
mul xl, yl, xl
mul ip, yl, ip
adds xl, xl, yh, lsl #16
adc xh, xh, yh, lsr #16
adds xl, xl, ip, lsl #16
adc xh, xh, ip, lsr #16
mov pc, lr