From 6d55a017fa066be53beded94e09c1c2e23253a6a Mon Sep 17 00:00:00 2001
From: Joel Sing <joel@sing.id.au>
Date: Wed, 16 Aug 2023 01:03:51 +1000
Subject: [PATCH] crypto/sha256: provide optimised assembly for riscv64
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Provide an optimised assembly implementation of sha256 for riscv64.
This results in considerable performance gains.

On a StarFive VisionFive 2:

                    │   sha256.1   │              sha256.2               │
                    │    sec/op    │   sec/op     vs base                │
Hash8Bytes/New-4       7.820µ ± 0%   5.193µ ± 0%  -33.59% (p=0.000 n=10)
Hash8Bytes/Sum224-4    7.918µ ± 0%   5.294µ ± 0%  -33.15% (p=0.000 n=10)
Hash8Bytes/Sum256-4    7.950µ ± 0%   5.320µ ± 0%  -33.08% (p=0.000 n=10)
Hash1K/New-4          108.03µ ± 0%   66.12µ ± 0%  -38.79% (p=0.000 n=10)
Hash1K/Sum224-4       108.12µ ± 0%   66.22µ ± 0%  -38.76% (p=0.000 n=10)
Hash1K/Sum256-4       108.15µ ± 0%   66.24µ ± 0%  -38.75% (p=0.000 n=10)
Hash8K/New-4           808.5µ ± 0%   493.0µ ± 0%  -39.02% (p=0.000 n=10)
Hash8K/Sum224-4        808.6µ ± 0%   493.1µ ± 0%  -39.02% (p=0.000 n=10)
Hash8K/Sum256-4        808.6µ ± 0%   493.1µ ± 0%  -39.02% (p=0.000 n=10)
geomean                88.37µ        55.61µ       -37.08%

                    │   sha256.1   │               sha256.2                │
                    │     B/s      │      B/s       vs base                │
Hash8Bytes/New-4      996.1Ki ± 0%   1503.9Ki ± 0%  +50.98% (p=0.000 n=10)
Hash8Bytes/Sum224-4   986.3Ki ± 0%   1474.6Ki ± 0%  +49.50% (p=0.000 n=10)
Hash8Bytes/Sum256-4   986.3Ki ± 0%   1464.8Ki ± 0%  +48.51% (p=0.000 n=10)
Hash1K/New-4          9.041Mi ± 0%   14.772Mi ± 0%  +63.40% (p=0.000 n=10)
Hash1K/Sum224-4       9.031Mi ± 0%   14.744Mi ± 0%  +63.25% (p=0.000 n=10)
Hash1K/Sum256-4       9.031Mi ± 0%   14.744Mi ± 0%  +63.25% (p=0.000 n=10)
Hash8K/New-4          9.661Mi ± 0%   15.850Mi ± 0%  +64.07% (p=0.000 n=10)
Hash8K/Sum224-4       9.661Mi ± 0%   15.841Mi ± 0%  +63.97% (p=0.000 n=10)
Hash8K/Sum256-4       9.661Mi ± 0%   15.841Mi ± 0%  +63.97% (p=0.000 n=10)
geomean               4.386Mi         6.966Mi       +58.85%

Change-Id: Ieead7b7c02291d70ddc472a7a8cf3c044c1da4b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/519695
Reviewed-by: Mark Ryan <markdryan@rivosinc.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
---
 src/crypto/sha256/sha256block_decl.go    |   2 +-
 src/crypto/sha256/sha256block_generic.go |   2 +-
 src/crypto/sha256/sha256block_riscv64.s  | 263 +++++++++++++++++++++++
 3 files changed, 265 insertions(+), 2 deletions(-)
 create mode 100644 src/crypto/sha256/sha256block_riscv64.s

diff --git a/src/crypto/sha256/sha256block_decl.go b/src/crypto/sha256/sha256block_decl.go
index 85374cbdbb5..d622c3b1744 100644
--- a/src/crypto/sha256/sha256block_decl.go
+++ b/src/crypto/sha256/sha256block_decl.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (386 || amd64 || s390x || ppc64le || ppc64) && !purego
+//go:build (386 || amd64 || s390x || ppc64le || ppc64 || riscv64) && !purego
 
 package sha256
 
diff --git a/src/crypto/sha256/sha256block_generic.go b/src/crypto/sha256/sha256block_generic.go
index 2964255f99c..4d21bdffbd8 100644
--- a/src/crypto/sha256/sha256block_generic.go
+++ b/src/crypto/sha256/sha256block_generic.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (!amd64 && !386 && !s390x && !ppc64le && !ppc64 && !arm64) || purego
+//go:build (!386 && !amd64 && !arm64 && !ppc64 && !ppc64le && !riscv64 && !s390x) || purego
 
 package sha256
 
diff --git a/src/crypto/sha256/sha256block_riscv64.s b/src/crypto/sha256/sha256block_riscv64.s
new file mode 100644
index 00000000000..f31bfb8d53d
--- /dev/null
+++ b/src/crypto/sha256/sha256block_riscv64.s
@@ -0,0 +1,263 @@
+// Copyright 2023 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 !purego
+
+#include "textflag.h"
+
+// SHA256 block routine. See sha256block.go for Go equivalent.
+//
+// The algorithm is detailed in FIPS 180-4:
+//
+//  https://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf
+//
+// Wt = Mt; for 0 <= t <= 15
+// Wt = SIGMA1(Wt-2) + SIGMA0(Wt-15) + Wt-16; for 16 <= t <= 63
+//
+// a = H0
+// b = H1
+// c = H2
+// d = H3
+// e = H4
+// f = H5
+// g = H6
+// h = H7
+//
+// for t = 0 to 63 {
+//    T1 = h + BIGSIGMA1(e) + Ch(e,f,g) + Kt + Wt
+//    T2 = BIGSIGMA0(a) + Maj(a,b,c)
+//    h = g
+//    g = f
+//    f = e
+//    e = d + T1
+//    d = c
+//    c = b
+//    b = a
+//    a = T1 + T2
+// }
+//
+// H0 = a + H0
+// H1 = b + H1
+// H2 = c + H2
+// H3 = d + H3
+// H4 = e + H4
+// H5 = f + H5
+// H6 = g + H6
+// H7 = h + H7
+
+// Wt = Mt; for 0 <= t <= 15
+#define MSGSCHEDULE0(index) \
+	MOVBU	((index*4)+0)(X29), X5; \
+	MOVBU	((index*4)+1)(X29), X6; \
+	MOVBU	((index*4)+2)(X29), X7; \
+	MOVBU	((index*4)+3)(X29), X8; \
+	SLL	$24, X5; \
+	SLL	$16, X6; \
+	OR	X5, X6, X5; \
+	SLL	$8, X7; \
+	OR	X5, X7, X5; \
+	OR	X5, X8, X5; \
+	MOVW	X5, (index*4)(X19)
+
+// Wt = SIGMA1(Wt-2) + Wt-7 + SIGMA0(Wt-15) + Wt-16; for 16 <= t <= 63
+//   SIGMA0(x) = ROTR(7,x) XOR ROTR(18,x) XOR SHR(3,x)
+//   SIGMA1(x) = ROTR(17,x) XOR ROTR(19,x) XOR SHR(10,x)
+#define MSGSCHEDULE1(index) \
+	MOVWU	(((index-2)&0xf)*4)(X19), X5; \
+	MOVWU	(((index-15)&0xf)*4)(X19), X6; \
+	MOVWU	(((index-7)&0xf)*4)(X19), X9; \
+	MOVWU	(((index-16)&0xf)*4)(X19), X21; \
+	RORW	$17, X5, X7; \
+	RORW	$19, X5, X8; \
+	SRL	$10, X5; \
+	XOR	X7, X5; \
+	XOR	X8, X5; \
+	ADD	X9, X5; \
+	RORW	$7, X6, X7; \
+	RORW	$18, X6, X8; \
+	SRL	$3, X6; \
+	XOR	X7, X6; \
+	XOR	X8, X6; \
+	ADD	X6, X5; \
+	ADD	X21, X5; \
+	MOVW	X5, ((index&0xf)*4)(X19)
+
+// Calculate T1 in X5.
+// h is also used as an accumulator. Wt is passed in X5.
+//   T1 = h + BIGSIGMA1(e) + Ch(e, f, g) + Kt + Wt
+//     BIGSIGMA1(x) = ROTR(6,x) XOR ROTR(11,x) XOR ROTR(25,x)
+//     Ch(x, y, z) = (x AND y) XOR (NOT x AND z)
+#define SHA256T1(index, e, f, g, h) \
+	MOVWU	(index*4)(X18), X8; \
+	ADD	X5, h; \
+	RORW	$6, e, X6; \
+	ADD	X8, h; \
+	RORW	$11, e, X7; \
+	XOR	X7, X6; \
+	RORW	$25, e, X8; \
+	XOR	X8, X6; \
+	ADD	X6, h; \
+	AND	e, f, X5; \
+	NOT	e, X7; \
+	AND	g, X7; \
+	XOR	X7, X5; \
+	ADD	h, X5
+
+// Calculate T2 in X6.
+//   T2 = BIGSIGMA0(a) + Maj(a, b, c)
+//     BIGSIGMA0(x) = ROTR(2,x) XOR ROTR(13,x) XOR ROTR(22,x)
+//     Maj(x, y, z) = (x AND y) XOR (x AND z) XOR (y AND z)
+#define SHA256T2(a, b, c) \
+	RORW	$2, a, X6; \
+	RORW	$13, a, X7; \
+	XOR	X7, X6; \
+	RORW	$22, a, X8; \
+	XOR	X8, X6; \
+	AND	a, b, X7; \
+	AND	a, c, X8; \
+	XOR	X8, X7; \
+	AND	b, c, X9; \
+	XOR	X9, X7; \
+	ADD	X7, X6
+
+// Calculate T1 and T2, then e = d + T1 and a = T1 + T2.
+// The values for e and a are stored in d and h, ready for rotation.
+#define SHA256ROUND(index, a, b, c, d, e, f, g, h) \
+	SHA256T1(index, e, f, g, h); \
+	SHA256T2(a, b, c); \
+	MOV	X6, h; \
+	ADD	X5, d; \
+	ADD	X5, h
+
+#define SHA256ROUND0(index, a, b, c, d, e, f, g, h) \
+	MSGSCHEDULE0(index); \
+	SHA256ROUND(index, a, b, c, d, e, f, g, h)
+
+#define SHA256ROUND1(index, a, b, c, d, e, f, g, h) \
+	MSGSCHEDULE1(index); \
+	SHA256ROUND(index, a, b, c, d, e, f, g, h)
+
+// Note that 64 bytes of stack space is used as a circular buffer
+// for the message schedule (4 bytes * 16 entries).
+//
+// func block(dig *digest, p []byte)
+TEXT ·block(SB),0,$64-32
+	MOV	p_base+8(FP), X29
+	MOV	p_len+16(FP), X30
+	SRL	$6, X30
+	SLL	$6, X30
+
+	ADD	X29, X30, X28
+	BEQ	X28, X29, end
+
+	MOV	·_K(SB), X18		// const table
+	ADD	$8, X2, X19		// message schedule
+
+	MOV	dig+0(FP), X20
+	MOVWU	(0*4)(X20), X10		// a = H0
+	MOVWU	(1*4)(X20), X11		// b = H1
+	MOVWU	(2*4)(X20), X12		// c = H2
+	MOVWU	(3*4)(X20), X13		// d = H3
+	MOVWU	(4*4)(X20), X14		// e = H4
+	MOVWU	(5*4)(X20), X15		// f = H5
+	MOVWU	(6*4)(X20), X16		// g = H6
+	MOVWU	(7*4)(X20), X17		// h = H7
+
+loop:
+	SHA256ROUND0(0, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND0(1, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND0(2, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND0(3, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND0(4, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND0(5, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND0(6, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND0(7, X11, X12, X13, X14, X15, X16, X17, X10)
+	SHA256ROUND0(8, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND0(9, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND0(10, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND0(11, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND0(12, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND0(13, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND0(14, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND0(15, X11, X12, X13, X14, X15, X16, X17, X10)
+
+	SHA256ROUND1(16, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND1(17, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND1(18, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND1(19, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND1(20, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND1(21, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND1(22, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND1(23, X11, X12, X13, X14, X15, X16, X17, X10)
+	SHA256ROUND1(24, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND1(25, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND1(26, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND1(27, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND1(28, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND1(29, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND1(30, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND1(31, X11, X12, X13, X14, X15, X16, X17, X10)
+	SHA256ROUND1(32, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND1(33, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND1(34, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND1(35, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND1(36, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND1(37, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND1(38, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND1(39, X11, X12, X13, X14, X15, X16, X17, X10)
+	SHA256ROUND1(40, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND1(41, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND1(42, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND1(43, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND1(44, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND1(45, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND1(46, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND1(47, X11, X12, X13, X14, X15, X16, X17, X10)
+	SHA256ROUND1(48, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND1(49, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND1(50, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND1(51, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND1(52, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND1(53, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND1(54, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND1(55, X11, X12, X13, X14, X15, X16, X17, X10)
+	SHA256ROUND1(56, X10, X11, X12, X13, X14, X15, X16, X17)
+	SHA256ROUND1(57, X17, X10, X11, X12, X13, X14, X15, X16)
+	SHA256ROUND1(58, X16, X17, X10, X11, X12, X13, X14, X15)
+	SHA256ROUND1(59, X15, X16, X17, X10, X11, X12, X13, X14)
+	SHA256ROUND1(60, X14, X15, X16, X17, X10, X11, X12, X13)
+	SHA256ROUND1(61, X13, X14, X15, X16, X17, X10, X11, X12)
+	SHA256ROUND1(62, X12, X13, X14, X15, X16, X17, X10, X11)
+	SHA256ROUND1(63, X11, X12, X13, X14, X15, X16, X17, X10)
+
+	MOVWU	(0*4)(X20), X5
+	MOVWU	(1*4)(X20), X6
+	MOVWU	(2*4)(X20), X7
+	MOVWU	(3*4)(X20), X8
+	ADD	X5, X10		// H0 = a + H0
+	ADD	X6, X11		// H1 = b + H1
+	ADD	X7, X12		// H2 = c + H2
+	ADD	X8, X13		// H3 = d + H3
+	MOVW	X10, (0*4)(X20)
+	MOVW	X11, (1*4)(X20)
+	MOVW	X12, (2*4)(X20)
+	MOVW	X13, (3*4)(X20)
+	MOVWU	(4*4)(X20), X5
+	MOVWU	(5*4)(X20), X6
+	MOVWU	(6*4)(X20), X7
+	MOVWU	(7*4)(X20), X8
+	ADD	X5, X14		// H4 = e + H4
+	ADD	X6, X15		// H5 = f + H5
+	ADD	X7, X16		// H6 = g + H6
+	ADD	X8, X17		// H7 = h + H7
+	MOVW	X14, (4*4)(X20)
+	MOVW	X15, (5*4)(X20)
+	MOVW	X16, (6*4)(X20)
+	MOVW	X17, (7*4)(X20)
+
+	ADD	$64, X29
+	BNE	X28, X29, loop
+
+end:
+	RET
-- 
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