| // This function is used to check for the CPU's support for the sdiv |
| // instruction at runtime. It will either return the value 1 or |
| // will cause an invalid instruction trap (SIGILL signal). The |
| // caller must arrange for the signal handler to set the r0 |
| // register to 0 and move the pc forward by 4 bytes (to skip |
| // the invalid instruction). |
| |
| |
| #include "asm_support_arm.S" |
| |
| .section .text |
| ENTRY_NO_HIDE CheckForARMSDIVInstruction |
| mov r1,#1 |
| // depending on the architecture, the assembler will not allow an |
| // sdiv instruction, so we will have to output the bytes directly. |
| |
| // sdiv r0,r1,r1 is two words: 0xfb91 0xf1f0. We need little endian. |
| .byte 0x91,0xfb,0xf1,0xf0 |
| |
| // if the divide worked, r0 will have the value #1 (result of sdiv). |
| // It will have 0 otherwise (set by the signal handler) |
| // the value is just returned from this function. |
| bx lr |
| END CheckForARMSDIVInstruction |
