diff options
Diffstat (limited to 'arch/blackfin/lib/modsi3.S')
-rw-r--r-- | arch/blackfin/lib/modsi3.S | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/blackfin/lib/modsi3.S b/arch/blackfin/lib/modsi3.S new file mode 100644 index 000000000..f7026ce1f --- /dev/null +++ b/arch/blackfin/lib/modsi3.S @@ -0,0 +1,57 @@ +/* + * 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 Clear 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 |