/* strchr/strchrnul optimized with AVX2.

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#if IS_IN (libc)

# include <sysdep.h>

# ifndef STRCHR

#  define STRCHR	__strchr_avx2

# endif

# ifdef USE_AS_WCSCHR

#  define VPBROADCAST	vpbroadcastd

#  define VPCMPEQ	vpcmpeqd

#  define CHAR_REG	esi

# else

#  define VPBROADCAST	vpbroadcastb

#  define VPCMPEQ	vpcmpeqb

#  define CHAR_REG	sil

# endif

# ifndef VZEROUPPER

#  define VZEROUPPER	vzeroupper

# endif

# define VEC_SIZE 32

	.section .text.avx,"ax",@progbits

ENTRY (STRCHR)

	movl	%edi, %ecx

	/* Broadcast CHAR to YMM0.  */

	vmovd	%esi, %xmm0

	vpxor	%xmm9, %xmm9, %xmm9

	VPBROADCAST %xmm0, %ymm0

	/* Check if we may cross page boundary with one vector load.  */

	andl	$(2 * VEC_SIZE - 1), %ecx

	cmpl	$VEC_SIZE, %ecx

	ja	L(cros_page_boundary)

	/* Check the first VEC_SIZE bytes.  Search for both CHAR and the

	   null byte.  */

	vmovdqu	(%rdi), %ymm8

	VPCMPEQ %ymm8, %ymm0, %ymm1

	VPCMPEQ %ymm8, %ymm9, %ymm2

	vpor	%ymm1, %ymm2, %ymm1

	vpmovmskb %ymm1, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x0)

	/* Align data for aligned loads in the loop.  */

	addq	$VEC_SIZE, %rdi

	andl	$(VEC_SIZE - 1), %ecx

	andq	$-VEC_SIZE, %rdi

	jmp	L(more_4x_vec)

	.p2align 4

L(cros_page_boundary):

	andl	$(VEC_SIZE - 1), %ecx

	andq	$-VEC_SIZE, %rdi

	vmovdqu	(%rdi), %ymm8

	VPCMPEQ %ymm8, %ymm0, %ymm1

	VPCMPEQ %ymm8, %ymm9, %ymm2

	vpor	%ymm1, %ymm2, %ymm1

	vpmovmskb %ymm1, %eax

	/* Remove the leading bytes.  */

	sarl	%cl, %eax

	testl	%eax, %eax

	jz	L(aligned_more)

	/* Found CHAR or the null byte.  */

	tzcntl	%eax, %eax

	addq	%rcx, %rax

# ifdef USE_AS_STRCHRNUL

	addq	%rdi, %rax

# else

	xorl	%edx, %edx

	leaq	(%rdi, %rax), %rax

	cmp	(%rax), %CHAR_REG

	cmovne	%rdx, %rax

# endif

	VZEROUPPER

	ret

	.p2align 4

L(aligned_more):

	addq	$VEC_SIZE, %rdi

L(more_4x_vec):

	/* Check the first 4 * VEC_SIZE.  Only one VEC_SIZE at a time

	   since data is only aligned to VEC_SIZE.  */

	vmovdqa	(%rdi), %ymm8

	VPCMPEQ %ymm8, %ymm0, %ymm1

	VPCMPEQ %ymm8, %ymm9, %ymm2

	vpor	%ymm1, %ymm2, %ymm1

	vpmovmskb %ymm1, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x0)

	vmovdqa	VEC_SIZE(%rdi), %ymm8

	VPCMPEQ %ymm8, %ymm0, %ymm1

	VPCMPEQ %ymm8, %ymm9, %ymm2

	vpor	%ymm1, %ymm2, %ymm1

	vpmovmskb %ymm1, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x1)

	vmovdqa	(VEC_SIZE * 2)(%rdi), %ymm8

	VPCMPEQ %ymm8, %ymm0, %ymm1

	VPCMPEQ %ymm8, %ymm9, %ymm2

	vpor	%ymm1, %ymm2, %ymm1

	vpmovmskb %ymm1, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x2)

	vmovdqa	(VEC_SIZE * 3)(%rdi), %ymm8

	VPCMPEQ %ymm8, %ymm0, %ymm1

	VPCMPEQ %ymm8, %ymm9, %ymm2

	vpor	%ymm1, %ymm2, %ymm1

	vpmovmskb %ymm1, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x3)

	addq	$(VEC_SIZE * 4), %rdi

	/* Align data to 4 * VEC_SIZE.  */

	movq	%rdi, %rcx

	andl	$(4 * VEC_SIZE - 1), %ecx

	andq	$-(4 * VEC_SIZE), %rdi

	.p2align 4

L(loop_4x_vec):

	/* Compare 4 * VEC at a time forward.  */

	vmovdqa	(%rdi), %ymm5

	vmovdqa	VEC_SIZE(%rdi), %ymm6

	vmovdqa	(VEC_SIZE * 2)(%rdi), %ymm7

	vmovdqa	(VEC_SIZE * 3)(%rdi), %ymm8

	VPCMPEQ %ymm5, %ymm0, %ymm1

	VPCMPEQ %ymm6, %ymm0, %ymm2

	VPCMPEQ %ymm7, %ymm0, %ymm3

	VPCMPEQ %ymm8, %ymm0, %ymm4

	VPCMPEQ %ymm5, %ymm9, %ymm5

	VPCMPEQ %ymm6, %ymm9, %ymm6

	VPCMPEQ %ymm7, %ymm9, %ymm7

	VPCMPEQ %ymm8, %ymm9, %ymm8

	vpor	%ymm1, %ymm5, %ymm1

	vpor	%ymm2, %ymm6, %ymm2

	vpor	%ymm3, %ymm7, %ymm3

	vpor	%ymm4, %ymm8, %ymm4

	vpor	%ymm1, %ymm2, %ymm5

	vpor	%ymm3, %ymm4, %ymm6

	vpor	%ymm5, %ymm6, %ymm5

	vpmovmskb %ymm5, %eax

	testl	%eax, %eax

	jnz	L(4x_vec_end)

	addq	$(VEC_SIZE * 4), %rdi

	jmp	L(loop_4x_vec)

	.p2align 4

L(first_vec_x0):

	/* Found CHAR or the null byte.  */

	tzcntl	%eax, %eax

# ifdef USE_AS_STRCHRNUL

	addq	%rdi, %rax

# else

	xorl	%edx, %edx

	leaq	(%rdi, %rax), %rax

	cmp	(%rax), %CHAR_REG

	cmovne	%rdx, %rax

# endif

	VZEROUPPER

	ret

	.p2align 4

L(first_vec_x1):

	tzcntl	%eax, %eax

# ifdef USE_AS_STRCHRNUL

	addq	$VEC_SIZE, %rax

	addq	%rdi, %rax

# else

	xorl	%edx, %edx

	leaq	VEC_SIZE(%rdi, %rax), %rax

	cmp	(%rax), %CHAR_REG

	cmovne	%rdx, %rax

# endif

	VZEROUPPER

	ret

	.p2align 4

L(first_vec_x2):

	tzcntl	%eax, %eax

# ifdef USE_AS_STRCHRNUL

	addq	$(VEC_SIZE * 2), %rax

	addq	%rdi, %rax

# else

	xorl	%edx, %edx

	leaq	(VEC_SIZE * 2)(%rdi, %rax), %rax

	cmp	(%rax), %CHAR_REG

	cmovne	%rdx, %rax

# endif

	VZEROUPPER

	ret

	.p2align 4

L(4x_vec_end):

	vpmovmskb %ymm1, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x0)

	vpmovmskb %ymm2, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x1)

	vpmovmskb %ymm3, %eax

	testl	%eax, %eax

	jnz	L(first_vec_x2)

	vpmovmskb %ymm4, %eax

	testl	%eax, %eax

L(first_vec_x3):

	tzcntl	%eax, %eax

# ifdef USE_AS_STRCHRNUL

	addq	$(VEC_SIZE * 3), %rax

	addq	%rdi, %rax

# else

	xorl	%edx, %edx

	leaq	(VEC_SIZE * 3)(%rdi, %rax), %rax

	cmp	(%rax), %CHAR_REG

	cmovne	%rdx, %rax

# endif

	VZEROUPPER

	ret

END (STRCHR)

#endif