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Diffstat (limited to 'compiler-rt/lib/builtins/arm/divsi3.S')
-rw-r--r-- | compiler-rt/lib/builtins/arm/divsi3.S | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/arm/divsi3.S b/compiler-rt/lib/builtins/arm/divsi3.S new file mode 100644 index 000000000000..761bf49d3ed0 --- /dev/null +++ b/compiler-rt/lib/builtins/arm/divsi3.S @@ -0,0 +1,81 @@ +//===-- 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): + mov 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 + |