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      1  1.1  joerg /*===-- modsi3.S - 32-bit signed integer modulus --------------------------===//
      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 __modsi3 (32-bit signed integer modulus) 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 @ int __modsi3(int divident, int divisor)
     29  1.2    rin @   Calculate and return the remainder of the (signed) division.
     30  1.2    rin 
     31  1.2    rin 	.p2align 3
     32  1.2    rin #if __ARM_ARCH_ISA_THUMB == 2
     33  1.2    rin DEFINE_COMPILERRT_THUMB_FUNCTION(__modsi3)
     34  1.2    rin #else
     35  1.1  joerg DEFINE_COMPILERRT_FUNCTION(__modsi3)
     36  1.2    rin #endif
     37  1.1  joerg #if __ARM_ARCH_EXT_IDIV__
     38  1.1  joerg 	tst     r1, r1
     39  1.1  joerg 	beq     LOCAL_LABEL(divzero)
     40  1.1  joerg 	sdiv	r2, r0, r1
     41  1.1  joerg 	mls 	r0, r2, r1, r0
     42  1.1  joerg 	bx      lr
     43  1.1  joerg LOCAL_LABEL(divzero):
     44  1.1  joerg 	mov     r0, #0
     45  1.1  joerg 	bx      lr
     46  1.1  joerg #else
     47  1.1  joerg     ESTABLISH_FRAME
     48  1.1  joerg     //  Set aside the sign of the dividend.
     49  1.1  joerg     mov     r4,     r0
     50  1.1  joerg     //  Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
     51  1.1  joerg     eor     r2,     r0, r0, asr #31
     52  1.1  joerg     eor     r3,     r1, r1, asr #31
     53  1.1  joerg     sub     r0,     r2, r0, asr #31
     54  1.1  joerg     sub     r1,     r3, r1, asr #31
     55  1.1  joerg     //  abs(a) % abs(b)
     56  1.1  joerg     bl     SYMBOL_NAME(__umodsi3)
     57  1.1  joerg     //  Apply sign of dividend to result and return.
     58  1.1  joerg     eor     r0,     r0, r4, asr #31
     59  1.1  joerg     sub     r0,     r0, r4, asr #31
     60  1.1  joerg     CLEAR_FRAME_AND_RETURN
     61  1.1  joerg #endif
     62  1.1  joerg END_COMPILERRT_FUNCTION(__modsi3)
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