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-rw-r--r--arch/microblaze/lib/umodsi3.S86
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diff --git a/arch/microblaze/lib/umodsi3.S b/arch/microblaze/lib/umodsi3.S
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1#include <linux/linkage.h>
2
3/*
4 * Unsigned modulo operation for 32 bit integers.
5 * Input : op1 in Reg r5
6 * op2 in Reg r6
7 * Output: op1 mod op2 in Reg r3
8 */
9
10 .text
11 .globl __umodsi3
12 .type __umodsi3, @function
13 .ent __umodsi3
14
15__umodsi3:
16 .frame r1, 0, r15
17
18 addik r1, r1, -12
19 swi r29, r1, 0
20 swi r30, r1, 4
21 swi r31, r1, 8
22
23 beqi r6, div_by_zero /* div_by_zero - division error */
24 beqid r5, result_is_zero /* result is zero */
25 addik r3, r0, 0 /* clear div */
26 addik r30, r0, 0 /* clear mod */
27 addik r29, r0, 32 /* initialize the loop count */
28
29/* check if r6 and r5 are equal /* if yes, return 0 */
30 rsub r18, r5, r6
31 beqi r18, return_here
32
33/* check if (uns)r6 is greater than (uns)r5. in that case, just return r5 */
34 xor r18, r5, r6
35 bgeid r18, 16
36 addik r3, r5, 0
37 blti r6, return_here
38 bri $lcheckr6
39 rsub r18, r5, r6 /* microblazecmp */
40 bgti r18, return_here
41
42/* if r6 [bit 31] is set, then return result as r5-r6 */
43$lcheckr6:
44 bgtid r6, div0
45 addik r3, r0, 0
46 addik r18, r0, 0x7fffffff
47 and r5, r5, r18
48 and r6, r6, r18
49 brid return_here
50 rsub r3, r6, r5
51/* first part: try to find the first '1' in the r5 */
52div0:
53 blti r5, div2
54div1:
55 add r5, r5, r5 /* left shift logical r5 */
56 bgeid r5, div1
57 addik r29, r29, -1
58div2:
59 /* left shift logical r5 get the '1' into the carry */
60 add r5, r5, r5
61 addc r3, r3, r3 /* move that bit into the mod register */
62 rsub r31, r6, r3 /* try to subtract (r3 a r6) */
63 blti r31, mod_too_small
64 /* move the r31 to mod since the result was positive */
65 or r3, r0, r31
66 addik r30, r30, 1
67mod_too_small:
68 addik r29, r29, -1
69 beqi r29, loop_end
70 add r30, r30, r30 /* shift in the '1' into div */
71 bri div2 /* div2 */
72loop_end:
73 bri return_here
74div_by_zero:
75result_is_zero:
76 or r3, r0, r0 /* set result to 0 */
77return_here:
78/* restore values of csrs and that of r3 and the divisor and the dividend */
79 lwi r29, r1, 0
80 lwi r30, r1, 4
81 lwi r31, r1, 8
82 rtsd r15, 8
83 addik r1, r1, 12
84
85.size __umodsi3, . - __umodsi3
86.end __umodsi3