1/* 2 * File: arch/blackfin/lib/modsi3.S 3 * Based on: 4 * Author: 5 * 6 * Created: 7 * Description: This program computes 32 bit signed remainder. It calls div32 function 8 * for quotient estimation. 9 * 10 * Registers used : 11 * Numerator/ Denominator in R0, R1 12 * R0 - returns remainder. 13 * R2-R7 14 * 15 * Modified: 16 * Copyright 2004-2006 Analog Devices Inc. 17 * 18 * Bugs: Enter bugs at http://blackfin.uclinux.org/ 19 * 20 * This program is free software; you can redistribute it and/or modify 21 * it under the terms of the GNU General Public License as published by 22 * the Free Software Foundation; either version 2 of the License, or 23 * (at your option) any later version. 24 * 25 * This program is distributed in the hope that it will be useful, 26 * but WITHOUT ANY WARRANTY; without even the implied warranty of 27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 28 * GNU General Public License for more details. 29 * 30 * You should have received a copy of the GNU General Public License 31 * along with this program; if not, see the file COPYING, or write 32 * to the Free Software Foundation, Inc., 33 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 34 */ 35 36.global ___modsi3; 37.type ___modsi3, STT_FUNC; 38.extern ___divsi3; 39.type ___divsi3, STT_FUNC; 40 41#ifdef CONFIG_ARITHMETIC_OPS_L1 42.section .l1.text 43#else 44.text 45#endif 46 47___modsi3: 48 49 CC=R0==0; 50 IF CC JUMP .LRETURN_R0; /* Return 0, if numerator == 0 */ 51 CC=R1==0; 52 IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == 0 */ 53 CC=R0==R1; 54 IF CC JUMP .LRETURN_ZERO; /* Return 0, if numerator == denominator */ 55 CC = R1 == 1; 56 IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == 1 */ 57 CC = R1 == -1; 58 IF CC JUMP .LRETURN_ZERO; /* Return 0, if denominator == -1 */ 59 60 /* Valid input. Use __divsi3() to compute the quotient, and then 61 * derive the remainder from that. */ 62 63 [--SP] = (R7:6); /* Push R7 and R6 */ 64 [--SP] = RETS; /* and return address */ 65 R7 = R0; /* Copy of R0 */ 66 R6 = R1; /* Save for later */ 67 SP += -12; /* Should always provide this space */ 68 CALL ___divsi3; /* Compute signed quotient using ___divsi3()*/ 69 SP += 12; 70 R0 *= R6; /* Quotient * divisor */ 71 R0 = R7 - R0; /* Dividend - (quotient * divisor) */ 72 RETS = [SP++]; /* Get back return address */ 73 (R7:6) = [SP++]; /* Pop registers R7 and R4 */ 74 RTS; /* Store remainder */ 75 76.LRETURN_ZERO: 77 R0 = 0; 78.LRETURN_R0: 79 RTS; 80 81.size ___modsi3, .-___modsi3 82