/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-â
âvi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :viâ
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#include "libc/macros.internal.h"

.ident "\n\
AVX2 SHA-1 (BSD-3 License)\n\
Copyright 2014 Intel Corporation\n"
.include "libc/disclaimer.inc"

#define	CTX	%rdi	/* arg1 */
#define BUF	%rsi	/* arg2 */
#define CNT	%rdx	/* arg3 */

#define	REG_A	%ecx
#define	REG_B	%esi
#define	REG_C	%edi
#define	REG_D	%eax
#define	REG_E	%edx
#define	REG_TB	%ebx
#define	REG_TA	%r12d
#define	REG_RA	%rcx
#define	REG_RB	%rsi
#define	REG_RC	%rdi
#define	REG_RD	%rax
#define	REG_RE	%rdx
#define	REG_RTA	%r12
#define	REG_RTB	%rbx
#define	REG_T1	%r11d
#define	xmm_mov	vmovups
#define	RND_F1	1
#define	RND_F2	2
#define	RND_F3	3

.macro REGALLOC
	.set A, REG_A
	.set B, REG_B
	.set C, REG_C
	.set D, REG_D
	.set E, REG_E
	.set TB, REG_TB
	.set TA, REG_TA
	.set RA, REG_RA
	.set RB, REG_RB
	.set RC, REG_RC
	.set RD, REG_RD
	.set RE, REG_RE
	.set RTA, REG_RTA
	.set RTB, REG_RTB
	.set T1, REG_T1
.endm

#define HASH_PTR	%r9
#define BLOCKS_CTR	%r8
#define BUFFER_PTR	%r10
#define BUFFER_PTR2	%r13

#define PRECALC_BUF	%r14
#define WK_BUF		%r15

#define W_TMP		%xmm0
#define WY_TMP		%ymm0
#define WY_TMP2		%ymm9

# AVX2 variables
#define WY0		%ymm3
#define WY4		%ymm5
#define WY08		%ymm7
#define WY12		%ymm8
#define WY16		%ymm12
#define WY20		%ymm13
#define WY24		%ymm14
#define WY28		%ymm15

#define YMM_SHUFB_BSWAP	%ymm10

/*
 * Keep 2 iterations precalculated at a time:
 *    - 80 DWORDs per iteration * 2
 */
#define W_SIZE		(80*2*2 +16)

#define WK(t)	((((t) % 80) / 4)*32 + ( (t) % 4)*4 + ((t)/80)*16 )(WK_BUF)
#define PRECALC_WK(t)	((t)*2*2)(PRECALC_BUF)


.macro UPDATE_HASH  hash, val
	add	\hash, \val
	mov	\val, \hash
.endm

.macro PRECALC_RESET_WY
	.set WY_00, WY0
	.set WY_04, WY4
	.set WY_08, WY08
	.set WY_12, WY12
	.set WY_16, WY16
	.set WY_20, WY20
	.set WY_24, WY24
	.set WY_28, WY28
	.set WY_32, WY_00
.endm

.macro PRECALC_ROTATE_WY
	/* Rotate macros */
	.set WY_32, WY_28
	.set WY_28, WY_24
	.set WY_24, WY_20
	.set WY_20, WY_16
	.set WY_16, WY_12
	.set WY_12, WY_08
	.set WY_08, WY_04
	.set WY_04, WY_00
	.set WY_00, WY_32

	/* Define register aliases */
	.set WY, WY_00
	.set WY_minus_04, WY_04
	.set WY_minus_08, WY_08
	.set WY_minus_12, WY_12
	.set WY_minus_16, WY_16
	.set WY_minus_20, WY_20
	.set WY_minus_24, WY_24
	.set WY_minus_28, WY_28
	.set WY_minus_32, WY
.endm

.macro PRECALC_00_15
	.if (i == 0) # Initialize and rotate registers
		PRECALC_RESET_WY
		PRECALC_ROTATE_WY
	.endif
	/* message scheduling pre-compute for rounds 0-15 */
	.if   ((i & 7) == 0)
		/*
		 * blended AVX2 and ALU instruction scheduling
		 * 1 vector iteration per 8 rounds
		 */
		vmovdqu (i * 2)(BUFFER_PTR), W_TMP
	.elseif ((i & 7) == 1)
		vinsertf128 $1, ((i-1) * 2)(BUFFER_PTR2),\
			 WY_TMP, WY_TMP
	.elseif ((i & 7) == 2)
		vpshufb YMM_SHUFB_BSWAP, WY_TMP, WY
	.elseif ((i & 7) == 4)
		vpaddd  K_XMM + K_XMM_AR(%rip), WY, WY_TMP
	.elseif ((i & 7) == 7)
		vmovdqu  WY_TMP, PRECALC_WK(i&~7)
		PRECALC_ROTATE_WY
	.endif
.endm

.macro PRECALC_16_31
	/*
	 * message scheduling pre-compute for rounds 16-31
	 * calculating last 32 w[i] values in 8 XMM registers
	 * pre-calculate K+w[i] values and store to mem
	 * for later load by ALU add instruction
	 *
	 * "brute force" vectorization for rounds 16-31 only
	 * due to w[i]->w[i-3] dependency
	 */
	.if   ((i & 7) == 0)
		/*
		 * blended AVX2 and ALU instruction scheduling
		 * 1 vector iteration per 8 rounds
		 */
		/* w[i-14] */
		vpalignr	$8, WY_minus_16, WY_minus_12, WY
		vpsrldq	$4, WY_minus_04, WY_TMP               /* w[i-3] */
	.elseif ((i & 7) == 1)
		vpxor	WY_minus_08, WY, WY
		vpxor	WY_minus_16, WY_TMP, WY_TMP
	.elseif ((i & 7) == 2)
		vpxor	WY_TMP, WY, WY
		vpslldq	$12, WY, WY_TMP2
	.elseif ((i & 7) == 3)
		vpslld	$1, WY, WY_TMP
		vpsrld	$31, WY, WY
	.elseif ((i & 7) == 4)
		vpor	WY, WY_TMP, WY_TMP
		vpslld	$2, WY_TMP2, WY
	.elseif ((i & 7) == 5)
		vpsrld	$30, WY_TMP2, WY_TMP2
		vpxor	WY, WY_TMP, WY_TMP
	.elseif ((i & 7) == 7)
		vpxor	WY_TMP2, WY_TMP, WY
		vpaddd  K_XMM + K_XMM_AR(%rip), WY, WY_TMP
		vmovdqu	WY_TMP, PRECALC_WK(i&~7)
		PRECALC_ROTATE_WY
	.endif
.endm

.macro PRECALC_32_79
	/*
	 * in SHA-1 specification:
	 * w[i] = (w[i-3] ^ w[i-8]  ^ w[i-14] ^ w[i-16]) rol 1
	 * instead we do equal:
	 * w[i] = (w[i-6] ^ w[i-16] ^ w[i-28] ^ w[i-32]) rol 2
	 * allows more efficient vectorization
	 * since w[i]=>w[i-3] dependency is broken
	 */
	.if   ((i & 7) == 0)
	/*
	 * blended AVX2 and ALU instruction scheduling
	 * 1 vector iteration per 8 rounds
	 */
		vpalignr	$8, WY_minus_08, WY_minus_04, WY_TMP
	.elseif ((i & 7) == 1)
		/* W is W_minus_32 before xor */
		vpxor	WY_minus_28, WY, WY
	.elseif ((i & 7) == 2)
		vpxor	WY_minus_16, WY_TMP, WY_TMP
	.elseif ((i & 7) == 3)
		vpxor	WY_TMP, WY, WY
	.elseif ((i & 7) == 4)
		vpslld	$2, WY, WY_TMP
	.elseif ((i & 7) == 5)
		vpsrld	$30, WY, WY
		vpor	WY, WY_TMP, WY
	.elseif ((i & 7) == 7)
		vpaddd  K_XMM + K_XMM_AR(%rip), WY, WY_TMP
		vmovdqu	WY_TMP, PRECALC_WK(i&~7)
		PRECALC_ROTATE_WY
	.endif
.endm

.macro PRECALC r, s
	.set i, \r
	.if (i < 40)
		.set K_XMM, 32*0
	.elseif (i < 80)
		.set K_XMM, 32*1
	.elseif (i < 120)
		.set K_XMM, 32*2
	.else
		.set K_XMM, 32*3
	.endif
	.if (i<32)
		PRECALC_00_15	\s
	.elseif (i<64)
		PRECALC_16_31	\s
	.elseif (i < 160)
		PRECALC_32_79	\s
	.endif
.endm

.macro ROTATE_STATE
	.set T_REG, E
	.set E, D
	.set D, C
	.set C, B
	.set B, TB
	.set TB, A
	.set A, T_REG
	.set T_REG, RE
	.set RE, RD
	.set RD, RC
	.set RC, RB
	.set RB, RTB
	.set RTB, RA
	.set RA, T_REG
.endm

//	Macro relies on saved ROUND_Fx
.macro	RND_FUN f, r
	.if (\f == RND_F1)
		ROUND_F1	\r
	.elseif (\f == RND_F2)
		ROUND_F2	\r
	.elseif (\f == RND_F3)
		ROUND_F3	\r
	.endif
.endm

.macro RR r
	.set round_id, (\r % 80)

	.if (round_id == 0)		# Precalculate F for first round
		.set ROUND_FUNC, RND_F1
		mov	B, TB

		rorx	$(32-30), B, B	# b>>>2
		andn	D, TB, T1
		and	C, TB
		xor	T1, TB
	.endif

	RND_FUN ROUND_FUNC, \r
	ROTATE_STATE

	.if   (round_id == 18)
		.set ROUND_FUNC, RND_F2
	.elseif (round_id == 38)
		.set ROUND_FUNC, RND_F3
	.elseif (round_id == 58)
		.set ROUND_FUNC, RND_F2
	.endif

	.set round_id, ( (\r+1) % 80)

	RND_FUN ROUND_FUNC, (\r+1)
	ROTATE_STATE
.endm

.macro ROUND_F1 r
	add	WK(\r), E

	andn	C, A, T1		# ~b&d
	lea	(RE,RTB), E		# Add F from the previous round

	rorx	$(32-5), A, TA		# T2 = A >>> 5
	rorx	$(32-30),A, TB		# b>>>2 for next round

	PRECALC	(\r)			# msg scheduling for next 2 blocks

//	Calculate F for the next round
//	(b & c) ^ andn[b, d]
	and	B, A			# b&c
	xor	T1, A			# F1 = (b&c) ^ (~b&d)

	lea	(RE,RTA), E		# E += A >>> 5
.endm

.macro ROUND_F2 r
	add	WK(\r), E
	lea	(RE,RTB), E		# Add F from the previous round

	/* Calculate F for the next round */
	rorx	$(32-5), A, TA		# T2 = A >>> 5
	.if ((round_id) < 79)
		rorx	$(32-30), A, TB	# b>>>2 for next round
	.endif
	PRECALC	(\r)			# msg scheduling for next 2 blocks

	.if ((round_id) < 79)
		xor	B, A
	.endif

	add	TA, E			# E += A >>> 5

	.if ((round_id) < 79)
		xor	C, A
	.endif
.endm

.macro ROUND_F3 r
	add	WK(\r), E
	PRECALC	(\r)			# msg scheduling for next 2 blocks

	lea	(RE,RTB), E		# Add F from the previous round

	mov	B, T1
	or	A, T1

	rorx	$(32-5), A, TA		# T2 = A >>> 5
	rorx	$(32-30), A, TB		# b>>>2 for next round

//	Calculate F for the next round
//	(b and c) or (d and (b or c))
	and	C, T1
	and	B, A
	or	T1, A

	add	TA, E			# E += A >>> 5

.endm

//	Add constant only if (%2 > %3) condition met (uses RTA as temp)
//	%1 + %2 >= %3 ? %4 : 0
.macro ADD_IF_GE a, b, c, d
	mov     \a, RTA
	add     $\d, RTA
	cmp     $\c, \b
	cmovge  RTA, \a
.endm

//	Performs 80 rounds of SHA-1 for multiple blocks with s/w pipelining
.macro SHA1_PIPELINED_MAIN_BODY

	REGALLOC

	mov	(HASH_PTR), A
	mov	4(HASH_PTR), B
	mov	8(HASH_PTR), C
	mov	12(HASH_PTR), D
	mov	16(HASH_PTR), E

	mov	%rsp, PRECALC_BUF
	lea	(2*4*80+32)(%rsp), WK_BUF

//	Precalc WK for first 2 blocks
	ADD_IF_GE BUFFER_PTR2, BLOCKS_CTR, 2, 64
	.set i, 0
	.rept    160
		PRECALC i
		.set i, i + 1
	.endr

//	Go to next block if needed
	ADD_IF_GE BUFFER_PTR, BLOCKS_CTR, 3, 128
	ADD_IF_GE BUFFER_PTR2, BLOCKS_CTR, 4, 128
	xchg	WK_BUF, PRECALC_BUF

	.balign 32
.L_loop:

//	code loops through more than one block
//	we use K_BASE value as a signal of a last block,
//	it is set below by: cmovae BUFFER_PTR, K_BASE
	test BLOCKS_CTR, BLOCKS_CTR
	jnz .L_begin
	.balign 32
	jmp	.L_end

	.balign 32
.L_begin:

//	process first block
//	rounds: 0,2,4,6,8
	.set j, 0
	.rept 5
		RR	j
		.set j, j+2
	.endr

	jmp .L_loop0
.L_loop0:

//	rounds
//	10,12,14,16,18
//	20,22,24,26,28
//	30,32,34,36,38
//	40,42,44,46,48
//	50,52,54,56,58
	.rept 25
		RR	j
		.set j, j+2
	.endr

//	Update Counter */
	sub $1, BLOCKS_CTR

//	Move to the next block only if needed*/
	ADD_IF_GE BUFFER_PTR, BLOCKS_CTR, 4, 128

//	rounds
//	60,62,64,66,68
//	70,72,74,76,78
	.rept 10
		RR	j
		.set j, j+2
	.endr

	UPDATE_HASH	(HASH_PTR), A
	UPDATE_HASH	4(HASH_PTR), TB
	UPDATE_HASH	8(HASH_PTR), C
	UPDATE_HASH	12(HASH_PTR), D
	UPDATE_HASH	16(HASH_PTR), E

	test	BLOCKS_CTR, BLOCKS_CTR
	jz	.L_loop

	mov	TB, B

//	process second block
//	 0+80, 2+80, 4+80, 6+80, 8+80
//	10+80,12+80,14+80,16+80,18+80

	.set j, 0
	.rept 10
		RR	j+80
		.set j, j+2
	.endr

	jmp	.L_loop1
.L_loop1:

//	rounds
//	20+80,22+80,24+80,26+80,28+80
//	30+80,32+80,34+80,36+80,38+80
	.rept 10
		RR	j+80
		.set j, j+2
	.endr

	jmp	.L_loop2
.L_loop2:

//	rounds
//	40+80,42+80,44+80,46+80,48+80
//	50+80,52+80,54+80,56+80,58+80
	.rept 10
		RR	j+80
		.set j, j+2
	.endr

//	update counter
	sub     $1, BLOCKS_CTR

//	Move to the next block only if needed
	ADD_IF_GE BUFFER_PTR2, BLOCKS_CTR, 4, 128

	jmp	.L_loop3
.L_loop3:

//	rounds
//	60+80,62+80,64+80,66+80,68+80
//	70+80,72+80,74+80,76+80,78+80
	.rept 10
		RR	j+80
		.set j, j+2
	.endr

	UPDATE_HASH	(HASH_PTR), A
	UPDATE_HASH	4(HASH_PTR), TB
	UPDATE_HASH	8(HASH_PTR), C
	UPDATE_HASH	12(HASH_PTR), D
	UPDATE_HASH	16(HASH_PTR), E

	/* Reset state for AVX2 reg permutation */
	mov	A, TA
	mov	TB, A
	mov	C, TB
	mov	E, C
	mov	D, B
	mov	TA, D

	REGALLOC

	xchg	WK_BUF, PRECALC_BUF

	jmp	.L_loop

	.balign 32
	.L_end:

.endm

.section .rodata

#define K1 0x5a827999
#define K2 0x6ed9eba1
#define K3 0x8f1bbcdc
#define K4 0xca62c1d6

.balign 128
K_XMM_AR:
	.long K1,K1,K1,K1
	.long K1,K1,K1,K1
	.long K2,K2,K2,K2
	.long K2,K2,K2,K2
	.long K3,K3,K3,K3
	.long K3,K3,K3,K3
	.long K4,K4,K4,K4
	.long K4,K4,K4,K4

BSWAP_SHUFB_CTL:
	.long 0x00010203
	.long 0x04050607
	.long 0x08090a0b
	.long 0x0c0d0e0f
	.long 0x00010203
	.long 0x04050607
	.long 0x08090a0b
	.long 0x0c0d0e0f
.text

//	Performs IntelÂ® AVX2â¢ optimized SHA-1 update.
//
//	This implementation is based on the previous SSSE3 release:
//	Visit http://software.intel.com/en-us/articles/ and refer
//	to improving-the-performance-of-the-secure-hash-algorithm-1/
//
//	Updates 20-byte SHA-1 record at start of 'state', from 'input',
//	for even number of 'blocks' consecutive 64-byte blocks.
//
//	    void sha1_transform_avx2(struct sha1_state *state,
//	                             const uint8_t *input,
//	                             int blocks);
//
//	@param	%rdi points to output digest
//	@param	%rsi points to input data
//	@param	%rdx is number of 64-byte blocks to process
//	@see	X86_HAVE(SHA)
sha1_transform_avx2:
	push	%rbp
	mov	%rsp,%rbp
	.profilable
	push	%rbx
	push	%r12
	push	%r13
	push	%r14
	push	%r15
	RESERVE_STACK  = (W_SIZE*4 + 8+24)
	/* Align stack */
	mov	%rsp,%rbx
	and	$~(0x20-1),%rsp
	push	%rbx
	sub	$RESERVE_STACK,%rsp
	vzeroupper
	/* Setup initial values */
	mov	CTX,HASH_PTR
	mov	BUF,BUFFER_PTR
	mov	BUF,BUFFER_PTR2
	mov	CNT,BLOCKS_CTR
	xmm_mov	BSWAP_SHUFB_CTL(%rip),YMM_SHUFB_BSWAP
	SHA1_PIPELINED_MAIN_BODY
	vzeroupper
	add	$RESERVE_STACK,%rsp
	pop	%rsp
	pop	%r15
	pop	%r14
	pop	%r13
	pop	%r12
	pop	%rbx
	pop	%rbp
	ret
	.endfn	sha1_transform_avx2,globl
