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Diffstat (limited to 'contrib/compiler-rt/lib/arm/modsi3.S')
| -rw-r--r-- | contrib/compiler-rt/lib/arm/modsi3.S | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/arm/modsi3.S b/contrib/compiler-rt/lib/arm/modsi3.S new file mode 100644 index 0000000..64a3afd --- /dev/null +++ b/contrib/compiler-rt/lib/arm/modsi3.S @@ -0,0 +1,36 @@ +//===-------- modsi3.S - Implement modsi3 ---------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "../assembly.h" + +// +// extern int32_t __modsi3(int32_t a, int32_t b); +// +// Returns the remainder when dividing two 32-bit signed integers. +// Conceptually, the function is: { return a - (a / b) * b; } +// But if you write that in C, llvm compiles it to a call to __modsi3... +// + .align 2 +DEFINE_COMPILERRT_FUNCTION(__modsi3) + push {r4, r5, r7, lr} + add r7, sp, #8 // set stack frame + mov r5, r0 // save a + mov r4, r1 // save b + bl ___divsi3 // compute a/b +#if __ARM_ARCH_7A__ + mls r0, r4, r0, r5 // mulitple result * b and subtract from a +#else + // before armv7, does not have "mls" instruction + mul r3, r0, r4 // multiple result * b + sub r0, r5, r3 // a - result +#endif + pop {r4, r5, r7, pc} + + + |
