| //===-------- modsi3.S - Implement modsi3 ---------------------------------===// |
| // |
| // 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. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #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} |
| |
| |
| |
