From 224c41c0d0d4f9e3d9624703c1668cd29e146da6 Mon Sep 17 00:00:00 2001
From: Sun Yimin <emmansun@users.noreply.github.com>
Date: Tue, 7 Nov 2023 08:54:30 +0800
Subject: [PATCH] internal/sm2ec: use neon for p256BigToLittle

---
 internal/sm2ec/p256_asm_arm64.s | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/internal/sm2ec/p256_asm_arm64.s b/internal/sm2ec/p256_asm_arm64.s
index a3b1e04..f649f91 100644
--- a/internal/sm2ec/p256_asm_arm64.s
+++ b/internal/sm2ec/p256_asm_arm64.s
@@ -80,16 +80,15 @@ TEXT ·p256BigToLittle(SB),NOSPLIT,$0
 	MOVD	res+0(FP), res_ptr
 	MOVD	in+8(FP), a_ptr
 
-	LDP	0*16(a_ptr), (acc0, acc1)
-	LDP	1*16(a_ptr), (acc2, acc3)
+	VLD1 (a_ptr), [V0.B16, V1.B16]
 
-	REV	acc0, acc0
-	REV	acc1, acc1
-	REV	acc2, acc2
-	REV	acc3, acc3
+	VEXT	$8, V0.B16, V0.B16, V2.B16
+	VEXT	$8, V1.B16, V1.B16, V3.B16
+	VREV64 V2.B16, V2.B16
+	VREV64 V3.B16, V3.B16
+
+	VST1 [V2.B16, V3.B16], (res_ptr)
 
-	STP	(acc3, acc2), 0*16(res_ptr)
-	STP	(acc1, acc0), 1*16(res_ptr)
 	RET
 /* ---------------------------------------*/
 // func p256MovCond(res, a, b *SM2P256Point, cond int)