1 /* 2 * memcmp - compare memory 3 * 4 * Copyright (c) 2018-2021, Arm Limited. 5 * SPDX-License-Identifier: MIT 6 */ 7 8 #include "../asmdefs.h" 9 10 #if __ARM_FEATURE_SVE 11 /* Assumptions: 12 * 13 * ARMv8-a, AArch64 14 * SVE Available. 15 */ 16 17 ENTRY (__memcmp_aarch64_sve) 18 PTR_ARG (0) 19 PTR_ARG (1) 20 SIZE_ARG (2) 21 mov x3, 0 /* initialize off */ 22 23 0: whilelo p0.b, x3, x2 /* while off < max */ 24 b.none 9f 25 26 ld1b z0.b, p0/z, [x0, x3] /* read vectors bounded by max. */ 27 ld1b z1.b, p0/z, [x1, x3] 28 29 /* Increment for a whole vector, even if we've only read a partial. 30 This is significantly cheaper than INCP, and since OFF is not 31 used after the loop it is ok to increment OFF past MAX. */ 32 incb x3 33 34 cmpne p1.b, p0/z, z0.b, z1.b /* while no inequalities */ 35 b.none 0b 36 37 /* Found inequality. */ 38 1: brkb p1.b, p0/z, p1.b /* find first such */ 39 lasta w0, p1, z0.b /* extract each byte */ 40 lasta w1, p1, z1.b 41 sub x0, x0, x1 /* return comparison */ 42 ret 43 44 /* Found end-of-count. */ 45 9: mov x0, 0 /* return equality */ 46 ret 47 48 END (__memcmp_aarch64_sve) 49 50 #endif 51 52