From c0055c1fb4cc99894451ae23fb9e724cc2bc9942 Mon Sep 17 00:00:00 2001
From: Sun Yimin <emmansun@users.noreply.github.com>
Date: Wed, 28 Aug 2024 08:38:36 +0800
Subject: [PATCH] intenal/subtle: s390x use VLM/VSTM

---
 internal/subtle/xor_s390x.s | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/internal/subtle/xor_s390x.s b/internal/subtle/xor_s390x.s
index 764a810..c6fa982 100644
--- a/internal/subtle/xor_s390x.s
+++ b/internal/subtle/xor_s390x.s
@@ -14,16 +14,39 @@ TEXT ·xorBytes(SB),NOSPLIT,$0-32
 	MOVD	n+24(FP), R4
 
 	MOVD	$0, R5
-	CMPBLT	R4, $16, less_than16
+	CMPBLT	R4, $64, less_than64
+
+loop64b:
+	VLM (R2)(R5*1), V0, V3
+	VLM (R3)(R5*1), V4, V7
+	VX V0, V4, V4
+	VX V1, V5, V5
+	VX V2, V6, V6
+	VX V3, V7, V7
+	VSTM V4, V7, (R1)(R5*1)
+	LAY	64(R5), R5
+	SUB	$64, R4
+	CMPBGE	R4, $64, loop64b
 
-loop16b:
+less_than64:
+	CMPBEQ	R4, $0, done // quick end
+	CMPBLT	R4, $32, less_than32
+	VLM (R2)(R5*1), V0, V1
+	VLM (R3)(R5*1), V2, V3
+	VX V0, V2, V2
+	VX V1, V3, V3
+	VSTM V2, V3, 0(R1)(R5*1)
+	LAY	32(R5), R5
+	SUB	$32, R4
+
+less_than32:
+	CMPBLT	R4, $16, less_than16
 	VL 0(R2)(R5*1), V0
 	VL 0(R3)(R5*1), V1
 	VX V0, V1, V2
 	VST V2, 0(R1)(R5*1)
 	LAY	16(R5), R5
 	SUB	$16, R4
-	CMPBGE	R4, $16, loop16b
 
 less_than16:
 	CMPBLT	R4, $8, tail