blob: 8a027b741efebde013360c5211089187e12b4589 [file] [log] [blame]
 /*===-- divmodsi4.S - 32-bit signed integer divide and modulus ------------===// * * The LLVM Compiler Infrastructure * * This file is dual licensed under the MIT and the University of Illinois Open * Source Licenses. See LICENSE.TXT for details. * *===----------------------------------------------------------------------===// * * This file implements the __divmodsi4 (32-bit signed integer divide and * modulus) function for the ARM architecture. A naive digit-by-digit * computation is employed for simplicity. * *===----------------------------------------------------------------------===*/ #include "../assembly.h" #define ESTABLISH_FRAME \ push {r4-r7, lr} ;\ add r7, sp, #12 #define CLEAR_FRAME_AND_RETURN \ pop {r4-r7, pc} .syntax unified .text DEFINE_CODE_STATE @ int __divmodsi4(int divident, int divisor, int *remainder) @ Calculate the quotient and remainder of the (signed) division. The return @ value is the quotient, the remainder is placed in the variable. .p2align 3 DEFINE_COMPILERRT_FUNCTION(__divmodsi4) #if __ARM_ARCH_EXT_IDIV__ tst r1, r1 beq LOCAL_LABEL(divzero) mov r3, r0 sdiv r0, r3, r1 mls r1, r0, r1, r3 str r1, [r2] bx lr LOCAL_LABEL(divzero): mov r0, #0 bx lr #else ESTABLISH_FRAME // Set aside the sign of the quotient and modulus, and the address for the // modulus. eor r4, r0, r1 mov r5, r0 mov r6, r2 // Take the absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). eor ip, r0, r0, asr #31 eor lr, r1, r1, asr #31 sub r0, ip, r0, asr #31 sub r1, lr, r1, asr #31 // Unsigned divmod: bl SYMBOL_NAME(__udivmodsi4) // Apply the sign of quotient and modulus ldr r1, [r6] eor r0, r0, r4, asr #31 eor r1, r1, r5, asr #31 sub r0, r0, r4, asr #31 sub r1, r1, r5, asr #31 str r1, [r6] CLEAR_FRAME_AND_RETURN #endif END_COMPILERRT_FUNCTION(__divmodsi4) NO_EXEC_STACK_DIRECTIVE