xref: /openbmc/linux/arch/microblaze/lib/mulsi3.S (revision 9cfc5c90)
1#include <linux/linkage.h>
2
3/*
4 * Multiply operation for 32 bit integers.
5 *	Input :	Operand1 in Reg r5
6 *		Operand2 in Reg r6
7 *	Output: Result [op1 * op2] in Reg r3
8 */
9	.text
10	.globl	__mulsi3
11	.type __mulsi3,  @function
12	.ent __mulsi3
13
14__mulsi3:
15	.frame	r1, 0, r15
16	add	r3, r0, r0
17	beqi	r5, result_is_zero /* multiply by zero */
18	beqi	r6, result_is_zero /* multiply by zero */
19	bgeid	r5, r5_pos
20	xor	r4, r5, r6 /* get the sign of the result */
21	rsubi	r5, r5, 0 /* make r5 positive */
22r5_pos:
23	bgei	r6, r6_pos
24	rsubi	r6, r6, 0 /* make r6 positive */
25r6_pos:
26	bri	l1
27l2:
28	add	r5, r5, r5
29l1:
30	srl	r6, r6
31	addc	r7, r0, r0
32	beqi	r7, l2
33	bneid	r6, l2
34	add	r3, r3, r5
35	blti	r4, negateresult
36	rtsd	r15, 8
37	nop
38negateresult:
39	rtsd	r15, 8
40	rsub	r3, r3, r0
41result_is_zero:
42	rtsd	r15, 8
43	addi	r3, r0, 0
44
45.size __mulsi3,  . - __mulsi3
46.end __mulsi3
47