Root/arch/blackfin/lib/modsi3.S

1/*
2 * This program computes 32 bit signed remainder. It calls div32 function
3 * for quotient estimation.
4 * Registers in: R0, R1 = Numerator/ Denominator
5 * Registers out: R0 = Remainder
6 *
7 * Copyright 2004-2009 Analog Devices Inc.
8 *
9 * Licensed under the ADI BSD license or the GPL-2 (or later)
10 */
11
12.global ___modsi3;
13.type ___modsi3, STT_FUNC;
14.extern ___divsi3;
15.type ___divsi3, STT_FUNC;
16
17#ifdef CONFIG_ARITHMETIC_OPS_L1
18.section .l1.text
19#else
20.text
21#endif
22
23___modsi3:
24
25    CC=R0==0;
26    IF CC JUMP .LRETURN_R0; /* Return 0, if numerator == 0 */
27    CC=R1==0;
28    IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == 0 */
29    CC=R0==R1;
30    IF CC JUMP .LRETURN_ZERO; /* Return 0, if numerator == denominator */
31    CC = R1 == 1;
32    IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == 1 */
33    CC = R1 == -1;
34    IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == -1 */
35
36    /* Valid input. Use __divsi3() to compute the quotient, and then
37     * derive the remainder from that. */
38
39    [--SP] = (R7:6); /* Push R7 and R6 */
40    [--SP] = RETS; /* and return address */
41    R7 = R0; /* Copy of R0 */
42    R6 = R1; /* Save for later */
43    SP += -12; /* Should always provide this space */
44    CALL ___divsi3; /* Compute signed quotient using ___divsi3()*/
45    SP += 12;
46    R0 *= R6; /* Quotient * divisor */
47    R0 = R7 - R0; /* Dividend - (quotient * divisor) */
48    RETS = [SP++]; /* Get back return address */
49    (R7:6) = [SP++]; /* Pop registers R7 and R4 */
50    RTS; /* Store remainder */
51
52.LRETURN_ZERO:
53    R0 = 0;
54.LRETURN_R0:
55    RTS;
56
57.size ___modsi3, .-___modsi3
58

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