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      1  1.1  joerg /*===-- divsi3.S - 32-bit signed integer divide ---------------------------===//
      2  1.1  joerg  *
      3  1.1  joerg  *                     The LLVM Compiler Infrastructure
      4  1.1  joerg  *
      5  1.1  joerg  * This file is dual licensed under the MIT and the University of Illinois Open
      6  1.1  joerg  * Source Licenses. See LICENSE.TXT for details.
      7  1.1  joerg  *
      8  1.1  joerg  *===----------------------------------------------------------------------===//
      9  1.1  joerg  *
     10  1.1  joerg  * This file implements the __divsi3 (32-bit signed integer divide) function
     11  1.1  joerg  * for the ARM architecture as a wrapper around the unsigned routine.
     12  1.1  joerg  *
     13  1.1  joerg  *===----------------------------------------------------------------------===*/
     14  1.1  joerg 
     15  1.1  joerg #include "../assembly.h"
     16  1.1  joerg 
     17  1.1  joerg #define ESTABLISH_FRAME \
     18  1.3  skrll     push   {r4, lr}
     19  1.1  joerg #define CLEAR_FRAME_AND_RETURN \
     20  1.3  skrll     pop    {r4, pc}
     21  1.1  joerg 
     22  1.2    rin 	.syntax unified
     23  1.2    rin 	.text
     24  1.2    rin #if __ARM_ARCH_ISA_THUMB == 2
     25  1.2    rin 	.thumb
     26  1.2    rin #endif
     27  1.2    rin 
     28  1.2    rin 	.p2align 3
     29  1.1  joerg // Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine.
     30  1.1  joerg DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3)
     31  1.2    rin 
     32  1.2    rin @ int __divsi3(int divident, int divisor)
     33  1.2    rin @   Calculate and return the quotient of the (signed) division.
     34  1.2    rin 
     35  1.2    rin #if __ARM_ARCH_ISA_THUMB == 2
     36  1.2    rin DEFINE_COMPILERRT_THUMB_FUNCTION(__divsi3)
     37  1.2    rin #else
     38  1.1  joerg DEFINE_COMPILERRT_FUNCTION(__divsi3)
     39  1.2    rin #endif
     40  1.1  joerg #if __ARM_ARCH_EXT_IDIV__
     41  1.1  joerg    tst     r1,r1
     42  1.1  joerg    beq     LOCAL_LABEL(divzero)
     43  1.1  joerg    sdiv    r0, r0, r1
     44  1.1  joerg    bx      lr
     45  1.1  joerg LOCAL_LABEL(divzero):
     46  1.1  joerg    mov     r0,#0
     47  1.1  joerg    bx      lr
     48  1.1  joerg #else
     49  1.1  joerg ESTABLISH_FRAME
     50  1.1  joerg //  Set aside the sign of the quotient.
     51  1.1  joerg     eor     r4,     r0, r1
     52  1.1  joerg //  Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
     53  1.1  joerg     eor     r2,     r0, r0, asr #31
     54  1.1  joerg     eor     r3,     r1, r1, asr #31
     55  1.1  joerg     sub     r0,     r2, r0, asr #31
     56  1.1  joerg     sub     r1,     r3, r1, asr #31
     57  1.1  joerg //  abs(a) / abs(b)
     58  1.1  joerg     bl      SYMBOL_NAME(__udivsi3)
     59  1.1  joerg //  Apply sign of quotient to result and return.
     60  1.1  joerg     eor     r0,     r0, r4, asr #31
     61  1.1  joerg     sub     r0,     r0, r4, asr #31
     62  1.1  joerg     CLEAR_FRAME_AND_RETURN
     63  1.1  joerg #endif
     64  1.1  joerg END_COMPILERRT_FUNCTION(__divsi3)
     65