satip-axe/kernel/arch/blackfin/lib/modsi3.S
2015-03-26 17:24:57 +01:00

58 lines
1.5 KiB
ArmAsm

/*
* This program computes 32 bit signed remainder. It calls div32 function
* for quotient estimation.
* Registers in: R0, R1 = Numerator/ Denominator
* Registers out: R0 = Remainder
*
* Copyright 2004-2009 Analog Devices Inc.
*
* Licensed under the ADI BSD license or the GPL-2 (or later)
*/
.global ___modsi3;
.type ___modsi3, STT_FUNC;
.extern ___divsi3;
.type ___divsi3, STT_FUNC;
#ifdef CONFIG_ARITHMETIC_OPS_L1
.section .l1.text
#else
.text
#endif
___modsi3:
CC=R0==0;
IF CC JUMP .LRETURN_R0; /* Return 0, if numerator == 0 */
CC=R1==0;
IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == 0 */
CC=R0==R1;
IF CC JUMP .LRETURN_ZERO; /* Return 0, if numerator == denominator */
CC = R1 == 1;
IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == 1 */
CC = R1 == -1;
IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == -1 */
/* Valid input. Use __divsi3() to compute the quotient, and then
* derive the remainder from that. */
[--SP] = (R7:6); /* Push R7 and R6 */
[--SP] = RETS; /* and return address */
R7 = R0; /* Copy of R0 */
R6 = R1; /* Save for later */
SP += -12; /* Should always provide this space */
CALL ___divsi3; /* Compute signed quotient using ___divsi3()*/
SP += 12;
R0 *= R6; /* Quotient * divisor */
R0 = R7 - R0; /* Dividend - (quotient * divisor) */
RETS = [SP++]; /* Get back return address */
(R7:6) = [SP++]; /* Pop registers R7 and R4 */
RTS; /* Store remainder */
.LRETURN_ZERO:
R0 = 0;
.LRETURN_R0:
RTS;
.size ___modsi3, .-___modsi3