diff options
Diffstat (limited to 'compiler-rt/lib/builtins/arm/modsi3.S')
| -rw-r--r-- | compiler-rt/lib/builtins/arm/modsi3.S | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/arm/modsi3.S b/compiler-rt/lib/builtins/arm/modsi3.S new file mode 100644 index 00000000000..07c5f9381ec --- /dev/null +++ b/compiler-rt/lib/builtins/arm/modsi3.S @@ -0,0 +1,51 @@ +/*===-- modsi3.S - 32-bit signed integer 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 __modsi3 (32-bit signed integer modulus) 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 +.align 3 +DEFINE_COMPILERRT_FUNCTION(__modsi3) +#if __ARM_ARCH_EXT_IDIV__ + tst r1, r1 + beq LOCAL_LABEL(divzero) + sdiv r2, r0, r1 + mls r0, r2, r1, r0 + bx lr +LOCAL_LABEL(divzero): + mov r0, #0 + bx lr +#else + ESTABLISH_FRAME + // Set aside the sign of the dividend. + mov r4, r0 + // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). + eor r2, r0, r0, asr #31 + eor r3, r1, r1, asr #31 + sub r0, r2, r0, asr #31 + sub r1, r3, r1, asr #31 + // abs(a) % abs(b) + bl SYMBOL_NAME(__umodsi3) + // Apply sign of dividend to result and return. + eor r0, r0, r4, asr #31 + sub r0, r0, r4, asr #31 + CLEAR_FRAME_AND_RETURN +#endif +END_COMPILERRT_FUNCTION(__modsi3) |
