1*0b57cec5SDimitry Andric//===-- divmodsi4.S - 32-bit signed integer divide and modulus ------------===// 2*0b57cec5SDimitry Andric// 3*0b57cec5SDimitry Andric// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric// See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric// 7*0b57cec5SDimitry Andric//===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric// 9*0b57cec5SDimitry Andric// This file implements the __divmodsi4 (32-bit signed integer divide and 10*0b57cec5SDimitry Andric// modulus) function for the ARM architecture. A naive digit-by-digit 11*0b57cec5SDimitry Andric// computation is employed for simplicity. 12*0b57cec5SDimitry Andric// 13*0b57cec5SDimitry Andric//===----------------------------------------------------------------------===// 14*0b57cec5SDimitry Andric 15*0b57cec5SDimitry Andric#include "../assembly.h" 16*0b57cec5SDimitry Andric 17*0b57cec5SDimitry Andric#define ESTABLISH_FRAME \ 18*0b57cec5SDimitry Andric push {r4-r7, lr} ;\ 19*0b57cec5SDimitry Andric add r7, sp, #12 20*0b57cec5SDimitry Andric#define CLEAR_FRAME_AND_RETURN \ 21*0b57cec5SDimitry Andric pop {r4-r7, pc} 22*0b57cec5SDimitry Andric 23*0b57cec5SDimitry Andric .syntax unified 24*0b57cec5SDimitry Andric .text 25*0b57cec5SDimitry Andric DEFINE_CODE_STATE 26*0b57cec5SDimitry Andric 27*0b57cec5SDimitry Andric@ int __divmodsi4(int divident, int divisor, int *remainder) 28*0b57cec5SDimitry Andric@ Calculate the quotient and remainder of the (signed) division. The return 29*0b57cec5SDimitry Andric@ value is the quotient, the remainder is placed in the variable. 30*0b57cec5SDimitry Andric 31*0b57cec5SDimitry Andric .p2align 3 32*0b57cec5SDimitry AndricDEFINE_COMPILERRT_FUNCTION(__divmodsi4) 33*0b57cec5SDimitry Andric#if __ARM_ARCH_EXT_IDIV__ 34*0b57cec5SDimitry Andric tst r1, r1 35*0b57cec5SDimitry Andric beq LOCAL_LABEL(divzero) 36*0b57cec5SDimitry Andric mov r3, r0 37*0b57cec5SDimitry Andric sdiv r0, r3, r1 38*0b57cec5SDimitry Andric mls r1, r0, r1, r3 39*0b57cec5SDimitry Andric str r1, [r2] 40*0b57cec5SDimitry Andric bx lr 41*0b57cec5SDimitry AndricLOCAL_LABEL(divzero): 42*0b57cec5SDimitry Andric mov r0, #0 43*0b57cec5SDimitry Andric bx lr 44*0b57cec5SDimitry Andric#else 45*0b57cec5SDimitry Andric ESTABLISH_FRAME 46*0b57cec5SDimitry Andric// Set aside the sign of the quotient and modulus, and the address for the 47*0b57cec5SDimitry Andric// modulus. 48*0b57cec5SDimitry Andric eor r4, r0, r1 49*0b57cec5SDimitry Andric mov r5, r0 50*0b57cec5SDimitry Andric mov r6, r2 51*0b57cec5SDimitry Andric// Take the absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 52*0b57cec5SDimitry Andric eor ip, r0, r0, asr #31 53*0b57cec5SDimitry Andric eor lr, r1, r1, asr #31 54*0b57cec5SDimitry Andric sub r0, ip, r0, asr #31 55*0b57cec5SDimitry Andric sub r1, lr, r1, asr #31 56*0b57cec5SDimitry Andric// Unsigned divmod: 57*0b57cec5SDimitry Andric bl SYMBOL_NAME(__udivmodsi4) 58*0b57cec5SDimitry Andric// Apply the sign of quotient and modulus 59*0b57cec5SDimitry Andric ldr r1, [r6] 60*0b57cec5SDimitry Andric eor r0, r0, r4, asr #31 61*0b57cec5SDimitry Andric eor r1, r1, r5, asr #31 62*0b57cec5SDimitry Andric sub r0, r0, r4, asr #31 63*0b57cec5SDimitry Andric sub r1, r1, r5, asr #31 64*0b57cec5SDimitry Andric str r1, [r6] 65*0b57cec5SDimitry Andric CLEAR_FRAME_AND_RETURN 66*0b57cec5SDimitry Andric#endif 67*0b57cec5SDimitry AndricEND_COMPILERRT_FUNCTION(__divmodsi4) 68*0b57cec5SDimitry Andric 69*0b57cec5SDimitry AndricNO_EXEC_STACK_DIRECTIVE 70*0b57cec5SDimitry Andric 71