From c90f36e3dd179d2de96f4f5fe38d8dc9a9de6dfe Mon Sep 17 00:00:00 2001
From: Emile <git@emile.space>
Date: Fri, 25 Oct 2024 15:55:50 +0200
Subject: vendor

---
 vendor/filippo.io/edwards25519/field/fe_arm64.s | 42 +++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 vendor/filippo.io/edwards25519/field/fe_arm64.s

(limited to 'vendor/filippo.io/edwards25519/field/fe_arm64.s')

diff --git a/vendor/filippo.io/edwards25519/field/fe_arm64.s b/vendor/filippo.io/edwards25519/field/fe_arm64.s
new file mode 100644
index 0000000..3126a43
--- /dev/null
+++ b/vendor/filippo.io/edwards25519/field/fe_arm64.s
@@ -0,0 +1,42 @@
+// Copyright (c) 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build arm64 && gc && !purego
+
+#include "textflag.h"
+
+// carryPropagate works exactly like carryPropagateGeneric and uses the
+// same AND, ADD, and LSR+MADD instructions emitted by the compiler, but
+// avoids loading R0-R4 twice and uses LDP and STP.
+//
+// See https://golang.org/issues/43145 for the main compiler issue.
+//
+// func carryPropagate(v *Element)
+TEXT ·carryPropagate(SB),NOFRAME|NOSPLIT,$0-8
+	MOVD v+0(FP), R20
+
+	LDP 0(R20), (R0, R1)
+	LDP 16(R20), (R2, R3)
+	MOVD 32(R20), R4
+
+	AND $0x7ffffffffffff, R0, R10
+	AND $0x7ffffffffffff, R1, R11
+	AND $0x7ffffffffffff, R2, R12
+	AND $0x7ffffffffffff, R3, R13
+	AND $0x7ffffffffffff, R4, R14
+
+	ADD R0>>51, R11, R11
+	ADD R1>>51, R12, R12
+	ADD R2>>51, R13, R13
+	ADD R3>>51, R14, R14
+	// R4>>51 * 19 + R10 -> R10
+	LSR $51, R4, R21
+	MOVD $19, R22
+	MADD R22, R10, R21, R10
+
+	STP (R10, R11), 0(R20)
+	STP (R12, R13), 16(R20)
+	MOVD R14, 32(R20)
+
+	RET
-- 
cgit 1.4.1