/*
* 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
