poly1305-sse2-x86_64.S

/*
 * Poly1305 authenticator algorithm, RFC7539, x64 SSE2 functions
 *
 * Copyright (C) 2015 Martin Willi
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/linkage.h>

.data
.align 16

ANMASK:	.octa 0x0000000003ffffff0000000003ffffff

.text

#define h0 0x00(%rdi)
#define h1 0x04(%rdi)
#define h2 0x08(%rdi)
#define h3 0x0c(%rdi)
#define h4 0x10(%rdi)
#define r0 0x00(%rdx)
#define r1 0x04(%rdx)
#define r2 0x08(%rdx)
#define r3 0x0c(%rdx)
#define r4 0x10(%rdx)
#define s1 0x00(%rsp)
#define s2 0x04(%rsp)
#define s3 0x08(%rsp)
#define s4 0x0c(%rsp)
#define m %rsi
#define h01 %xmm0
#define h23 %xmm1
#define h44 %xmm2
#define t1 %xmm3
#define t2 %xmm4
#define t3 %xmm5
#define t4 %xmm6
#define mask %xmm7
#define d0 %r8
#define d1 %r9
#define d2 %r10
#define d3 %r11
#define d4 %r12

ENTRY(poly1305_block_sse2)
	# %rdi: Accumulator h[5]
	# %rsi: 16 byte input block m
	# %rdx: Poly1305 key r[5]
	# %rcx: Block count

	# This single block variant tries to improve performance by doing two
	# multiplications in parallel using SSE instructions. There is quite
	# some quardword packing involved, hence the speedup is marginal.

	push		%rbx
	push		%r12
	sub		$0x10,%rsp

	# s1..s4 = r1..r4 * 5
	mov		r1,%eax
	lea		(%eax,%eax,4),%eax
	mov		%eax,s1
	mov		r2,%eax
	lea		(%eax,%eax,4),%eax
	mov		%eax,s2
	mov		r3,%eax
	lea		(%eax,%eax,4),%eax
	mov		%eax,s3
	mov		r4,%eax
	lea		(%eax,%eax,4),%eax
	mov		%eax,s4

	movdqa		ANMASK(%rip),mask

.Ldoblock:
	# h01 = [0, h1, 0, h0]
	# h23 = [0, h3, 0, h2]
	# h44 = [0, h4, 0, h4]
	movd		h0,h01
	movd		h1,t1
	movd		h2,h23
	movd		h3,t2
	movd		h4,h44
	punpcklqdq	t1,h01
	punpcklqdq	t2,h23
	punpcklqdq	h44,h44

	# h01 += [ (m[3-6] >> 2) & 0x3ffffff, m[0-3] & 0x3ffffff ]
	movd		0x00(m),t1
	movd		0x03(m),t2
	psrld		$2,t2
	punpcklqdq	t2,t1
	pand		mask,t1
	paddd		t1,h01
	# h23 += [ (m[9-12] >> 6) & 0x3ffffff, (m[6-9] >> 4) & 0x3ffffff ]
	movd		0x06(m),t1
	movd		0x09(m),t2
	psrld		$4,t1
	psrld		$6,t2
	punpcklqdq	t2,t1
	pand		mask,t1
	paddd		t1,h23
	# h44 += [ (m[12-15] >> 8) | (1 << 24), (m[12-15] >> 8) | (1 << 24) ]
	mov		0x0c(m),%eax
	shr		$8,%eax
	or		$0x01000000,%eax
	movd		%eax,t1
	pshufd		$0xc4,t1,t1
	paddd		t1,h44

	# t1[0] = h0 * r0 + h2 * s3
	# t1[1] = h1 * s4 + h3 * s2
	movd		r0,t1
	movd		s4,t2
	punpcklqdq	t2,t1
	pmuludq		h01,t1
	movd		s3,t2
	movd		s2,t3
	punpcklqdq	t3,t2
	pmuludq		h23,t2
	paddq		t2,t1
	# t2[0] = h0 * r1 + h2 * s4
	# t2[1] = h1 * r0 + h3 * s3
	movd		r1,t2
	movd		r0,t3
	punpcklqdq	t3,t2
	pmuludq		h01,t2
	movd		s4,t3
	movd		s3,t4
	punpcklqdq	t4,t3
	pmuludq		h23,t3
	paddq		t3,t2
	# t3[0] = h4 * s1
	# t3[1] = h4 * s2
	movd		s1,t3
	movd		s2,t4
	punpcklqdq	t4,t3
	pmuludq		h44,t3
	# d0 = t1[0] + t1[1] + t3[0]
	# d1 = t2[0] + t2[1] + t3[1]
	movdqa		t1,t4
	punpcklqdq	t2,t4
	punpckhqdq	t2,t1
	paddq		t4,t1
	paddq		t3,t1
	movq		t1,d0
	psrldq		$8,t1
	movq		t1,d1

	# t1[0] = h0 * r2 + h2 * r0
	# t1[1] = h1 * r1 + h3 * s4
	movd		r2,t1
	movd		r1,t2
	punpcklqdq 	t2,t1
	pmuludq		h01,t1
	movd		r0,t2
	movd		s4,t3
	punpcklqdq	t3,t2
	pmuludq		h23,t2
	paddq		t2,t1
	# t2[0] = h0 * r3 + h2 * r1
	# t2[1] = h1 * r2 + h3 * r0
	movd		r3,t2
	movd		r2,t3
	punpcklqdq	t3,t2
	pmuludq		h01,t2
	movd		r1,t3
	movd		r0,t4
	punpcklqdq	t4,t3
	pmuludq		h23,t3
	paddq		t3,t2
	# t3[0] = h4 * s3
	# t3[1] = h4 * s4
	movd		s3,t3
	movd		s4,t4
	punpcklqdq	t4,t3
	pmuludq		h44,t3
	# d2 = t1[0] + t1[1] + t3[0]
	# d3 = t2[0] + t2[1] + t3[1]
	movdqa		t1,t4
	punpcklqdq	t2,t4
	punpckhqdq	t2,t1
	paddq		t4,t1
	paddq		t3,t1
	movq		t1,d2
	psrldq		$8,t1
	movq		t1,d3

	# t1[0] = h0 * r4 + h2 * r2
	# t1[1] = h1 * r3 + h3 * r1
	movd		r4,t1
	movd		r3,t2
	punpcklqdq	t2,t1
	pmuludq		h01,t1
	movd		r2,t2
	movd		r1,t3
	punpcklqdq	t3,t2
	pmuludq		h23,t2
	paddq		t2,t1
	# t3[0] = h4 * r0
	movd		r0,t3
	pmuludq		h44,t3
	# d4 = t1[0] + t1[1] + t3[0]
	movdqa		t1,t4
	psrldq		$8,t4
	paddq		t4,t1
	paddq		t3,t1
	movq		t1,d4

	# d1 += d0 >> 26
	mov		d0,%rax
	shr		$26,%rax
	add		%rax,d1
	# h0 = d0 & 0x3ffffff
	mov		d0,%rbx
	and		$0x3ffffff,%ebx

	# d2 += d1 >> 26
	mov		d1,%rax
	shr		$26,%rax
	add		%rax,d2
	# h1 = d1 & 0x3ffffff
	mov		d1,%rax
	and		$0x3ffffff,%eax
	mov		%eax,h1

	# d3 += d2 >> 26
	mov		d2,%rax
	shr		$26,%rax
	add		%rax,d3
	# h2 = d2 & 0x3ffffff
	mov		d2,%rax
	and		$0x3ffffff,%eax
	mov		%eax,h2

	# d4 += d3 >> 26
	mov		d3,%rax
	shr		$26,%rax
	add		%rax,d4
	# h3 = d3 & 0x3ffffff
	mov		d3,%rax
	and		$0x3ffffff,%eax
	mov		%eax,h3

	# h0 += (d4 >> 26) * 5
	mov		d4,%rax
	shr		$26,%rax
	lea		(%eax,%eax,4),%eax
	add		%eax,%ebx
	# h4 = d4 & 0x3ffffff
	mov		d4,%rax
	and		$0x3ffffff,%eax
	mov		%eax,h4

	# h1 += h0 >> 26
	mov		%ebx,%eax
	shr		$26,%eax
	add		%eax,h1
	# h0 = h0 & 0x3ffffff
	andl		$0x3ffffff,%ebx
	mov		%ebx,h0

	add		$0x10,m
	dec		%rcx
	jnz		.Ldoblock

	add		$0x10,%rsp
	pop		%r12
	pop		%rbx
	ret
ENDPROC(poly1305_block_sse2)