//===-- divsi3.S - 32-bit signed integer divide ---------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file implements the __divsi3 (32-bit signed integer divide) function // for the ARM architecture as a wrapper around the unsigned routine. // //===----------------------------------------------------------------------===// #include "../assembly.h" #define ESTABLISH_FRAME \ push {r4, r7, lr} ;\ add r7, sp, #4 #define CLEAR_FRAME_AND_RETURN \ pop {r4, r7, pc} .syntax unified .text DEFINE_CODE_STATE .p2align 3 // Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) @ int __divsi3(int divident, int divisor) @ Calculate and return the quotient of the (signed) division. DEFINE_COMPILERRT_FUNCTION(__divsi3) #if __ARM_ARCH_EXT_IDIV__ tst r1,r1 beq LOCAL_LABEL(divzero) sdiv r0, r0, r1 bx lr LOCAL_LABEL(divzero): // Use movs for compatibility with v8-m.base. movs r0,#0 bx lr #else ESTABLISH_FRAME // Set aside the sign of the quotient. # if defined(USE_THUMB_1) movs r4, r0 eors r4, r1 # else eor r4, r0, r1 # endif // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). # if defined(USE_THUMB_1) asrs r2, r0, #31 asrs r3, r1, #31 eors r0, r2 eors r1, r3 subs r0, r0, r2 subs r1, r1, r3 # else eor r2, r0, r0, asr #31 eor r3, r1, r1, asr #31 sub r0, r2, r0, asr #31 sub r1, r3, r1, asr #31 # endif // abs(a) / abs(b) bl SYMBOL_NAME(__udivsi3) // Apply sign of quotient to result and return. # if defined(USE_THUMB_1) asrs r4, #31 eors r0, r4 subs r0, r0, r4 # else eor r0, r0, r4, asr #31 sub r0, r0, r4, asr #31 # endif CLEAR_FRAME_AND_RETURN #endif END_COMPILERRT_FUNCTION(__divsi3) NO_EXEC_STACK_DIRECTIVE