Subversion Repositories openrisc

/* Support file for -mfix-vr4120.
   Copyright (C) 2002, 2004, 2007 Free Software Foundation, Inc.

This file is part of GCC.

GCC 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 3, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

/* This file contains functions which implement divsi3 and modsi3 for
   -mfix-vr4120.  div and ddiv do not give the correct result when one
   of the operands is negative.  */

        .set    nomips16

#define DIV                                                             \
        xor     $3,$4,$5        /* t = x ^ y */ ;                       \
        li      $2,0x80000000;                                          \
        .set    noreorder;                                              \
        bgez    $4,1f           /* x >= 0 */;                           \
        and     $3,$3,$2        /* t = (x ^ y) & 0x80000000 in delay slot */ ;\
        .set    reorder;                                                \
        subu    $4,$0,$4        /* x = -x */ ;                          \
1:;                                                                     \
        .set    noreorder;                                              \
        bgez    $5,2f           /* y >= 0 */ ;                          \
        nop;                                                            \
        subu    $5,$0,$5        /* y = -y */ ;                          \
        .set    reorder;                                                \
2:;                                                                     \
        divu    $0,$4,$5;       /* we use divu because of INT_MIN */    \
        .set    noreorder;                                              \
        bne     $5,$0,3f;                                               \
        nop;                                                            \
        break   7               /* division on zero y */ ;              \
3:;                                                                     \
        .set    reorder;                                                \
        mflo    $2              /* r = x / y */ ;                       \
        .set    noreorder;                                              \
        beq     $3,$0,4f        /* t == 0 */ ;                          \
        nop;                                                            \
        subu    $2,$0,$2        /* r = -r */ ;                          \
        .set    reorder;                                                \
4:

        .globl  __vr4120_divsi3
        .ent    __vr4120_divsi3
__vr4120_divsi3:
        DIV
        j       $31
        .end    __vr4120_divsi3

        .globl  __vr4120_modsi3
        .ent    __vr4120_modsi3
__vr4120_modsi3:
        move    $6,$4           # x1 = x
        move    $7,$5           # y1 = y
        DIV
        mult    $2,$7           # r = r * y1
        mflo    $2
        .set    noreorder
        j       $31
        subu    $2,$6,$2        # r = x1 - r  in delay slot
        .end    __vr4120_modsi3