| /* |
| * memcmp - compare memory |
| * |
| * Copyright (c) 2018-2022, Arm Limited. |
| * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception |
| */ |
| |
| #include "asmdefs.h" |
| |
| #if __ARM_FEATURE_SVE |
| /* Assumptions: |
| * |
| * ARMv8-a, AArch64 |
| * SVE Available. |
| */ |
| |
| ENTRY (__memcmp_aarch64_sve) |
| PTR_ARG (0) |
| PTR_ARG (1) |
| SIZE_ARG (2) |
| mov x3, 0 /* initialize off */ |
| |
| 0: whilelo p0.b, x3, x2 /* while off < max */ |
| b.none 9f |
| |
| ld1b z0.b, p0/z, [x0, x3] /* read vectors bounded by max. */ |
| ld1b z1.b, p0/z, [x1, x3] |
| |
| /* Increment for a whole vector, even if we've only read a partial. |
| This is significantly cheaper than INCP, and since OFF is not |
| used after the loop it is ok to increment OFF past MAX. */ |
| incb x3 |
| |
| cmpne p1.b, p0/z, z0.b, z1.b /* while no inequalities */ |
| b.none 0b |
| |
| /* Found inequality. */ |
| 1: brkb p1.b, p0/z, p1.b /* find first such */ |
| lasta w0, p1, z0.b /* extract each byte */ |
| lasta w1, p1, z1.b |
| sub x0, x0, x1 /* return comparison */ |
| ret |
| |
| /* Found end-of-count. */ |
| 9: mov x0, 0 /* return equality */ |
| ret |
| |
| END (__memcmp_aarch64_sve) |
| |
| #endif |
| |