1*7c3d14c8STreehugger Robot/*===-- divmodsi4.S - 32-bit signed integer divide and modulus ------------===// 2*7c3d14c8STreehugger Robot * 3*7c3d14c8STreehugger Robot * The LLVM Compiler Infrastructure 4*7c3d14c8STreehugger Robot * 5*7c3d14c8STreehugger Robot * This file is dual licensed under the MIT and the University of Illinois Open 6*7c3d14c8STreehugger Robot * Source Licenses. See LICENSE.TXT for details. 7*7c3d14c8STreehugger Robot * 8*7c3d14c8STreehugger Robot *===----------------------------------------------------------------------===// 9*7c3d14c8STreehugger Robot * 10*7c3d14c8STreehugger Robot * This file implements the __divmodsi4 (32-bit signed integer divide and 11*7c3d14c8STreehugger Robot * modulus) function for the ARM architecture. A naive digit-by-digit 12*7c3d14c8STreehugger Robot * computation is employed for simplicity. 13*7c3d14c8STreehugger Robot * 14*7c3d14c8STreehugger Robot *===----------------------------------------------------------------------===*/ 15*7c3d14c8STreehugger Robot 16*7c3d14c8STreehugger Robot#include "../assembly.h" 17*7c3d14c8STreehugger Robot 18*7c3d14c8STreehugger Robot#define ESTABLISH_FRAME \ 19*7c3d14c8STreehugger Robot push {r4-r7, lr} ;\ 20*7c3d14c8STreehugger Robot add r7, sp, #12 21*7c3d14c8STreehugger Robot#define CLEAR_FRAME_AND_RETURN \ 22*7c3d14c8STreehugger Robot pop {r4-r7, pc} 23*7c3d14c8STreehugger Robot 24*7c3d14c8STreehugger Robot .syntax unified 25*7c3d14c8STreehugger Robot .text 26*7c3d14c8STreehugger Robot#if __ARM_ARCH_ISA_THUMB == 2 27*7c3d14c8STreehugger Robot .thumb 28*7c3d14c8STreehugger Robot#endif 29*7c3d14c8STreehugger Robot 30*7c3d14c8STreehugger Robot@ int __divmodsi4(int divident, int divisor, int *remainder) 31*7c3d14c8STreehugger Robot@ Calculate the quotient and remainder of the (signed) division. The return 32*7c3d14c8STreehugger Robot@ value is the quotient, the remainder is placed in the variable. 33*7c3d14c8STreehugger Robot 34*7c3d14c8STreehugger Robot .p2align 3 35*7c3d14c8STreehugger Robot#if __ARM_ARCH_ISA_THUMB == 2 36*7c3d14c8STreehugger RobotDEFINE_COMPILERRT_THUMB_FUNCTION(__divmodsi4) 37*7c3d14c8STreehugger Robot#else 38*7c3d14c8STreehugger RobotDEFINE_COMPILERRT_FUNCTION(__divmodsi4) 39*7c3d14c8STreehugger Robot#endif 40*7c3d14c8STreehugger Robot#if __ARM_ARCH_EXT_IDIV__ 41*7c3d14c8STreehugger Robot tst r1, r1 42*7c3d14c8STreehugger Robot beq LOCAL_LABEL(divzero) 43*7c3d14c8STreehugger Robot mov r3, r0 44*7c3d14c8STreehugger Robot sdiv r0, r3, r1 45*7c3d14c8STreehugger Robot mls r1, r0, r1, r3 46*7c3d14c8STreehugger Robot str r1, [r2] 47*7c3d14c8STreehugger Robot bx lr 48*7c3d14c8STreehugger RobotLOCAL_LABEL(divzero): 49*7c3d14c8STreehugger Robot mov r0, #0 50*7c3d14c8STreehugger Robot bx lr 51*7c3d14c8STreehugger Robot#else 52*7c3d14c8STreehugger Robot ESTABLISH_FRAME 53*7c3d14c8STreehugger Robot// Set aside the sign of the quotient and modulus, and the address for the 54*7c3d14c8STreehugger Robot// modulus. 55*7c3d14c8STreehugger Robot eor r4, r0, r1 56*7c3d14c8STreehugger Robot mov r5, r0 57*7c3d14c8STreehugger Robot mov r6, r2 58*7c3d14c8STreehugger Robot// Take the absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 59*7c3d14c8STreehugger Robot eor ip, r0, r0, asr #31 60*7c3d14c8STreehugger Robot eor lr, r1, r1, asr #31 61*7c3d14c8STreehugger Robot sub r0, ip, r0, asr #31 62*7c3d14c8STreehugger Robot sub r1, lr, r1, asr #31 63*7c3d14c8STreehugger Robot// Unsigned divmod: 64*7c3d14c8STreehugger Robot bl SYMBOL_NAME(__udivmodsi4) 65*7c3d14c8STreehugger Robot// Apply the sign of quotient and modulus 66*7c3d14c8STreehugger Robot ldr r1, [r6] 67*7c3d14c8STreehugger Robot eor r0, r0, r4, asr #31 68*7c3d14c8STreehugger Robot eor r1, r1, r5, asr #31 69*7c3d14c8STreehugger Robot sub r0, r0, r4, asr #31 70*7c3d14c8STreehugger Robot sub r1, r1, r5, asr #31 71*7c3d14c8STreehugger Robot str r1, [r6] 72*7c3d14c8STreehugger Robot CLEAR_FRAME_AND_RETURN 73*7c3d14c8STreehugger Robot#endif 74*7c3d14c8STreehugger RobotEND_COMPILERRT_FUNCTION(__divmodsi4) 75*7c3d14c8STreehugger Robot 76*7c3d14c8STreehugger RobotNO_EXEC_STACK_DIRECTIVE 77*7c3d14c8STreehugger Robot 78