From 51f8c4ca719ad1863e7d46278dca5beb1bac10d5 Mon Sep 17 00:00:00 2001
From: AmaxGuan <lguan@fb.com>
Date: Thu, 14 Dec 2023 00:15:32 -0800
Subject: [PATCH] Update memcpy-advsimd.S to preload the src into L1 at
 beginning of the function

In bionic benchmark on Android, with the preload instruction, memcpy performed 7.5% better on 16 bytes and 32 bytes benchmark without affecting performance of any other benchmark results.
---
 string/aarch64/memcpy-advsimd.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/string/aarch64/memcpy-advsimd.S b/string/aarch64/memcpy-advsimd.S
index e6527d0d..b791f679 100644
--- a/string/aarch64/memcpy-advsimd.S
+++ b/string/aarch64/memcpy-advsimd.S
@@ -55,6 +55,7 @@ ENTRY (__memcpy_aarch64_simd)
 	PTR_ARG (0)
 	PTR_ARG (1)
 	SIZE_ARG (2)
+	prfm    PLDL1KEEP, [src]
 	add	srcend, src, count
 	add	dstend, dstin, count
 	cmp	count, 128