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 Clear 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