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Diffstat (limited to 'arch/blackfin/lib/modsi3.S')
-rw-r--r-- | arch/blackfin/lib/modsi3.S | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/blackfin/lib/modsi3.S b/arch/blackfin/lib/modsi3.S new file mode 100644 index 000000000000..528b8b1ccb34 --- /dev/null +++ b/arch/blackfin/lib/modsi3.S @@ -0,0 +1,79 @@ +/* + * File: arch/blackfin/lib/modsi3.S + * Based on: + * Author: + * + * Created: + * Description: This program computes 32 bit signed remainder. It calls div32 function + * for quotient estimation. + * + * Registers used : + * Numerator/ Denominator in R0, R1 + * R0 - returns remainder. + * R2-R7 + * + * Modified: + * Copyright 2004-2006 Analog Devices Inc. + * + * Bugs: Enter bugs at http://blackfin.uclinux.org/ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see the file COPYING, or write + * to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +.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; |