x86: Move strlen SSE2 implementation to multiarch/strlen-sse2.S

This commit doesn't affect libc.so.6, its just housekeeping to prepare
for adding explicit ISA level support.

Tested build on x86_64 and x86_32 with/without multiarch.

9 files changed, 306 insertions, 286 deletions

diff --git a/sysdeps/x86_64/multiarch/rtld-strlen.S b/sysdeps/x86_64/multiarch/rtld-strlen.S
new file mode 100644
index 0000000..609d262
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/rtld-strlen.S
@@ -0,0 +1,18 @@
+/* Copyright (C) 2022 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include "../strlen.S"
diff --git a/sysdeps/x86_64/multiarch/rtld-strnlen.S b/sysdeps/x86_64/multiarch/rtld-strnlen.S
new file mode 100644
index 0000000..ef2d64a
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/rtld-strnlen.S
@@ -0,0 +1,18 @@
+/* Copyright (C) 2022 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include "../strnlen.S"
diff --git a/sysdeps/x86_64/multiarch/strlen-sse2.S b/sysdeps/x86_64/multiarch/strlen-sse2.S
index 660b327..5be7226 100644
--- a/sysdeps/x86_64/multiarch/strlen-sse2.S
+++ b/sysdeps/x86_64/multiarch/strlen-sse2.S
@@ -16,8 +16,260 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if IS_IN (libc)
-# define strlen __strlen_sse2
-#endif
+#if IS_IN (libc) || defined STRLEN
+
+# ifndef STRLEN
+#  define STRLEN __strlen_sse2
+# endif
+
+
+# include <sysdep.h>
+
+# ifdef AS_WCSLEN
+#  define PMINU		pminud
+#  define PCMPEQ		pcmpeqd
+#  define SHIFT_RETURN	shrq $2, %rax
+# else
+#  define PMINU		pminub
+#  define PCMPEQ		pcmpeqb
+#  define SHIFT_RETURN
+# endif
+
+# ifndef SECTION
+#  define SECTION(p)	p
+# endif
+
+/* Long lived register in strlen(s), strnlen(s, n) are:
+
+	%xmm3 - zero
+	%rdi   - s
+	%r10  (s+n) & (~(64-1))
+	%r11   s+n
+*/
+
+
+	.section SECTION(.text),"ax",@progbits
+ENTRY(STRLEN)
+
+/* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx.  */
+# define FIND_ZERO	\
+	PCMPEQ	(%rax), %xmm0;	\
+	PCMPEQ	16(%rax), %xmm1;	\
+	PCMPEQ	32(%rax), %xmm2;	\
+	PCMPEQ	48(%rax), %xmm3;	\
+	pmovmskb	%xmm0, %esi;	\
+	pmovmskb	%xmm1, %edx;	\
+	pmovmskb	%xmm2, %r8d;	\
+	pmovmskb	%xmm3, %ecx;	\
+	salq	$16, %rdx;	\
+	salq	$16, %rcx;	\
+	orq	%rsi, %rdx;	\
+	orq	%r8, %rcx;	\
+	salq	$32, %rcx;	\
+	orq	%rcx, %rdx;
+
+# ifdef AS_STRNLEN
+/* Do not read anything when n==0.  */
+	test	%RSI_LP, %RSI_LP
+	jne	L(n_nonzero)
+	xor	%rax, %rax
+	ret
+L(n_nonzero):
+#  ifdef AS_WCSLEN
+/* Check for overflow from maxlen * sizeof(wchar_t). If it would
+   overflow the only way this program doesn't have undefined behavior
+   is if there is a null terminator in valid memory so wcslen will
+   suffice.  */
+	mov	%RSI_LP, %R10_LP
+	sar	$62, %R10_LP
+	jnz	__wcslen_sse4_1
+	sal	$2, %RSI_LP
+#  endif
+
+/* Initialize long lived registers.  */
+	add	%RDI_LP, %RSI_LP
+	mov	%RSI_LP, %R10_LP
+	and	$-64, %R10_LP
+	mov	%RSI_LP, %R11_LP
+# endif
+
+	pxor	%xmm0, %xmm0
+	pxor	%xmm1, %xmm1
+	pxor	%xmm2, %xmm2
+	pxor	%xmm3, %xmm3
+	movq	%rdi, %rax
+	movq	%rdi, %rcx
+	andq	$4095, %rcx
+/* Offsets 4032-4047 will be aligned into 4032 thus fit into page.  */
+	cmpq	$4047, %rcx
+/* We cannot unify this branching as it would be ~6 cycles slower.  */
+	ja	L(cross_page)
+
+# ifdef AS_STRNLEN
+/* Test if end is among first 64 bytes.  */
+#  define STRNLEN_PROLOG	\
+	mov	%r11, %rsi;	\
+	subq	%rax, %rsi;	\
+	andq	$-64, %rax;	\
+	testq	$-64, %rsi;	\
+	je	L(strnlen_ret)
+# else
+#  define STRNLEN_PROLOG  andq $-64, %rax;
+# endif
+
+/* Ignore bits in mask that come before start of string.  */
+# define PROLOG(lab)	\
+	movq	%rdi, %rcx;	\
+	xorq	%rax, %rcx;	\
+	STRNLEN_PROLOG;	\
+	sarq	%cl, %rdx;	\
+	test	%rdx, %rdx;	\
+	je	L(lab);	\
+	bsfq	%rdx, %rax;	\
+	SHIFT_RETURN;		\
+	ret
+
+# ifdef AS_STRNLEN
+	andq	$-16, %rax
+	FIND_ZERO
+# else
+	/* Test first 16 bytes unaligned.  */
+	movdqu	(%rax), %xmm4
+	PCMPEQ	%xmm0, %xmm4
+	pmovmskb	%xmm4, %edx
+	test	%edx, %edx
+	je 	L(next48_bytes)
+	bsf	%edx, %eax /* If eax is zeroed 16bit bsf can be used.  */
+	SHIFT_RETURN
+	ret
+
+L(next48_bytes):
+/* Same as FIND_ZERO except we do not check first 16 bytes.  */
+	andq	$-16, %rax
+	PCMPEQ 16(%rax), %xmm1
+	PCMPEQ 32(%rax), %xmm2
+	PCMPEQ 48(%rax), %xmm3
+	pmovmskb	%xmm1, %edx
+	pmovmskb	%xmm2, %r8d
+	pmovmskb	%xmm3, %ecx
+	salq	$16, %rdx
+	salq	$16, %rcx
+	orq	%r8, %rcx
+	salq	$32, %rcx
+	orq	%rcx, %rdx
+# endif
 
-#include "strlen-vec.S"
+	/* When no zero byte is found xmm1-3 are zero so we do not have to
+	   zero them.  */
+	PROLOG(loop)
+
+	.p2align 4
+L(cross_page):
+	andq	$-64, %rax
+	FIND_ZERO
+	PROLOG(loop_init)
+
+# ifdef AS_STRNLEN
+/* We must do this check to correctly handle strnlen (s, -1).  */
+L(strnlen_ret):
+	bts	%rsi, %rdx
+	sarq	%cl, %rdx
+	test	%rdx, %rdx
+	je	L(loop_init)
+	bsfq	%rdx, %rax
+	SHIFT_RETURN
+	ret
+# endif
+	.p2align 4
+L(loop_init):
+	pxor	%xmm1, %xmm1
+	pxor	%xmm2, %xmm2
+	pxor	%xmm3, %xmm3
+# ifdef AS_STRNLEN
+	.p2align 4
+L(loop):
+
+	addq	$64, %rax
+	cmpq	%rax, %r10
+	je	L(exit_end)
+
+	movdqa	(%rax), %xmm0
+	PMINU	16(%rax), %xmm0
+	PMINU	32(%rax), %xmm0
+	PMINU	48(%rax), %xmm0
+	PCMPEQ	%xmm3, %xmm0
+	pmovmskb	%xmm0, %edx
+	testl	%edx, %edx
+	jne	L(exit)
+	jmp	L(loop)
+
+	.p2align 4
+L(exit_end):
+	cmp	%rax, %r11
+	je	L(first) /* Do not read when end is at page boundary.  */
+	pxor	%xmm0, %xmm0
+	FIND_ZERO
+
+L(first):
+	bts	%r11, %rdx
+	bsfq	%rdx, %rdx
+	addq	%rdx, %rax
+	subq	%rdi, %rax
+	SHIFT_RETURN
+	ret
+
+	.p2align 4
+L(exit):
+	pxor	%xmm0, %xmm0
+	FIND_ZERO
+
+	bsfq	%rdx, %rdx
+	addq	%rdx, %rax
+	subq	%rdi, %rax
+	SHIFT_RETURN
+	ret
+
+# else
+
+	/* Main loop.  Unrolled twice to improve L2 cache performance on core2.  */
+	.p2align 4
+L(loop):
+
+	movdqa	64(%rax), %xmm0
+	PMINU	80(%rax), %xmm0
+	PMINU	96(%rax), %xmm0
+	PMINU	112(%rax), %xmm0
+	PCMPEQ	%xmm3, %xmm0
+	pmovmskb	%xmm0, %edx
+	testl	%edx, %edx
+	jne	L(exit64)
+
+	subq	$-128, %rax
+
+	movdqa	(%rax), %xmm0
+	PMINU	16(%rax), %xmm0
+	PMINU	32(%rax), %xmm0
+	PMINU	48(%rax), %xmm0
+	PCMPEQ	%xmm3, %xmm0
+	pmovmskb	%xmm0, %edx
+	testl	%edx, %edx
+	jne	L(exit0)
+	jmp	L(loop)
+
+	.p2align 4
+L(exit64):
+	addq	$64, %rax
+L(exit0):
+	pxor	%xmm0, %xmm0
+	FIND_ZERO
+
+	bsfq	%rdx, %rdx
+	addq	%rdx, %rax
+	subq	%rdi, %rax
+	SHIFT_RETURN
+	ret
+
+# endif
+
+END(STRLEN)
+#endif
diff --git a/sysdeps/x86_64/multiarch/strlen-vec.S b/sysdeps/x86_64/multiarch/strlen-vec.S
deleted file mode 100644
index 874123d..0000000
--- a/sysdeps/x86_64/multiarch/strlen-vec.S
+++ /dev/null
@@ -1,267 +0,0 @@
-/* SSE2 version of strlen and SSE4.1 version of wcslen.
-   Copyright (C) 2012-2022 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-
-#ifdef AS_WCSLEN
-# define PMINU		pminud
-# define PCMPEQ		pcmpeqd
-# define SHIFT_RETURN	shrq $2, %rax
-#else
-# define PMINU		pminub
-# define PCMPEQ		pcmpeqb
-# define SHIFT_RETURN
-#endif
-
-#ifndef SECTION
-# define SECTION(p)	p
-#endif
-
-/* Long lived register in strlen(s), strnlen(s, n) are:
-
-	%xmm3 - zero
-	%rdi   - s
-	%r10  (s+n) & (~(64-1))
-	%r11   s+n
-*/
-
-
-	.section SECTION(.text),"ax",@progbits
-ENTRY(strlen)
-
-/* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx.  */
-#define FIND_ZERO	\
-	PCMPEQ	(%rax), %xmm0;	\
-	PCMPEQ	16(%rax), %xmm1;	\
-	PCMPEQ	32(%rax), %xmm2;	\
-	PCMPEQ	48(%rax), %xmm3;	\
-	pmovmskb	%xmm0, %esi;	\
-	pmovmskb	%xmm1, %edx;	\
-	pmovmskb	%xmm2, %r8d;	\
-	pmovmskb	%xmm3, %ecx;	\
-	salq	$16, %rdx;	\
-	salq	$16, %rcx;	\
-	orq	%rsi, %rdx;	\
-	orq	%r8, %rcx;	\
-	salq	$32, %rcx;	\
-	orq	%rcx, %rdx;
-
-#ifdef AS_STRNLEN
-/* Do not read anything when n==0.  */
-	test	%RSI_LP, %RSI_LP
-	jne	L(n_nonzero)
-	xor	%rax, %rax
-	ret
-L(n_nonzero):
-# ifdef AS_WCSLEN
-/* Check for overflow from maxlen * sizeof(wchar_t). If it would
-   overflow the only way this program doesn't have undefined behavior
-   is if there is a null terminator in valid memory so wcslen will
-   suffice.  */
-	mov	%RSI_LP, %R10_LP
-	sar	$62, %R10_LP
-	jnz	__wcslen_sse4_1
-	sal	$2, %RSI_LP
-# endif
-
-/* Initialize long lived registers.  */
-	add	%RDI_LP, %RSI_LP
-	mov	%RSI_LP, %R10_LP
-	and	$-64, %R10_LP
-	mov	%RSI_LP, %R11_LP
-#endif
-
-	pxor	%xmm0, %xmm0
-	pxor	%xmm1, %xmm1
-	pxor	%xmm2, %xmm2
-	pxor	%xmm3, %xmm3
-	movq	%rdi, %rax
-	movq	%rdi, %rcx
-	andq	$4095, %rcx
-/* Offsets 4032-4047 will be aligned into 4032 thus fit into page.  */
-	cmpq	$4047, %rcx
-/* We cannot unify this branching as it would be ~6 cycles slower.  */
-	ja	L(cross_page)
-
-#ifdef AS_STRNLEN
-/* Test if end is among first 64 bytes.  */
-# define STRNLEN_PROLOG	\
-	mov	%r11, %rsi;	\
-	subq	%rax, %rsi;	\
-	andq	$-64, %rax;	\
-	testq	$-64, %rsi;	\
-	je	L(strnlen_ret)
-#else
-# define STRNLEN_PROLOG  andq $-64, %rax;
-#endif
-
-/* Ignore bits in mask that come before start of string.  */
-#define PROLOG(lab)	\
-	movq	%rdi, %rcx;	\
-	xorq	%rax, %rcx;	\
-	STRNLEN_PROLOG;	\
-	sarq	%cl, %rdx;	\
-	test	%rdx, %rdx;	\
-	je	L(lab);	\
-	bsfq	%rdx, %rax;	\
-	SHIFT_RETURN;		\
-	ret
-
-#ifdef AS_STRNLEN
-	andq	$-16, %rax
-	FIND_ZERO
-#else
-	/* Test first 16 bytes unaligned.  */
-	movdqu	(%rax), %xmm4
-	PCMPEQ	%xmm0, %xmm4
-	pmovmskb	%xmm4, %edx
-	test	%edx, %edx
-	je 	L(next48_bytes)
-	bsf	%edx, %eax /* If eax is zeroed 16bit bsf can be used.  */
-	SHIFT_RETURN
-	ret
-
-L(next48_bytes):
-/* Same as FIND_ZERO except we do not check first 16 bytes.  */
-	andq	$-16, %rax
-	PCMPEQ 16(%rax), %xmm1
-	PCMPEQ 32(%rax), %xmm2
-	PCMPEQ 48(%rax), %xmm3
-	pmovmskb	%xmm1, %edx
-	pmovmskb	%xmm2, %r8d
-	pmovmskb	%xmm3, %ecx
-	salq	$16, %rdx
-	salq	$16, %rcx
-	orq	%r8, %rcx
-	salq	$32, %rcx
-	orq	%rcx, %rdx
-#endif
-
-	/* When no zero byte is found xmm1-3 are zero so we do not have to
-	   zero them.  */
-	PROLOG(loop)
-
-	.p2align 4
-L(cross_page):
-	andq	$-64, %rax
-	FIND_ZERO
-	PROLOG(loop_init)
-
-#ifdef AS_STRNLEN
-/* We must do this check to correctly handle strnlen (s, -1).  */
-L(strnlen_ret):
-	bts	%rsi, %rdx
-	sarq	%cl, %rdx
-	test	%rdx, %rdx
-	je	L(loop_init)
-	bsfq	%rdx, %rax
-	SHIFT_RETURN
-	ret
-#endif
-	.p2align 4
-L(loop_init):
-	pxor	%xmm1, %xmm1
-	pxor	%xmm2, %xmm2
-	pxor	%xmm3, %xmm3
-#ifdef AS_STRNLEN
-	.p2align 4
-L(loop):
-
-	addq	$64, %rax
-	cmpq	%rax, %r10
-	je	L(exit_end)
-
-	movdqa	(%rax), %xmm0
-	PMINU	16(%rax), %xmm0
-	PMINU	32(%rax), %xmm0
-	PMINU	48(%rax), %xmm0
-	PCMPEQ	%xmm3, %xmm0
-	pmovmskb	%xmm0, %edx
-	testl	%edx, %edx
-	jne	L(exit)
-	jmp	L(loop)
-
-	.p2align 4
-L(exit_end):
-	cmp	%rax, %r11
-	je	L(first) /* Do not read when end is at page boundary.  */
-	pxor	%xmm0, %xmm0
-	FIND_ZERO
-
-L(first):
-	bts	%r11, %rdx
-	bsfq	%rdx, %rdx
-	addq	%rdx, %rax
-	subq	%rdi, %rax
-	SHIFT_RETURN
-	ret
-
-	.p2align 4
-L(exit):
-	pxor	%xmm0, %xmm0
-	FIND_ZERO
-
-	bsfq	%rdx, %rdx
-	addq	%rdx, %rax
-	subq	%rdi, %rax
-	SHIFT_RETURN
-	ret
-
-#else
-
-	/* Main loop.  Unrolled twice to improve L2 cache performance on core2.  */
-	.p2align 4
-L(loop):
-
-	movdqa	64(%rax), %xmm0
-	PMINU	80(%rax), %xmm0
-	PMINU	96(%rax), %xmm0
-	PMINU	112(%rax), %xmm0
-	PCMPEQ	%xmm3, %xmm0
-	pmovmskb	%xmm0, %edx
-	testl	%edx, %edx
-	jne	L(exit64)
-
-	subq	$-128, %rax
-
-	movdqa	(%rax), %xmm0
-	PMINU	16(%rax), %xmm0
-	PMINU	32(%rax), %xmm0
-	PMINU	48(%rax), %xmm0
-	PCMPEQ	%xmm3, %xmm0
-	pmovmskb	%xmm0, %edx
-	testl	%edx, %edx
-	jne	L(exit0)
-	jmp	L(loop)
-
-	.p2align 4
-L(exit64):
-	addq	$64, %rax
-L(exit0):
-	pxor	%xmm0, %xmm0
-	FIND_ZERO
-
-	bsfq	%rdx, %rdx
-	addq	%rdx, %rax
-	subq	%rdi, %rax
-	SHIFT_RETURN
-	ret
-
-#endif
-
-END(strlen)
diff --git a/sysdeps/x86_64/multiarch/strnlen-sse2.S b/sysdeps/x86_64/multiarch/strnlen-sse2.S
index c4f395c..a50c7d6 100644
--- a/sysdeps/x86_64/multiarch/strnlen-sse2.S
+++ b/sysdeps/x86_64/multiarch/strnlen-sse2.S
@@ -17,12 +17,10 @@
    <https://www.gnu.org/licenses/>.  */
 
 #if IS_IN (libc)
-# define __strnlen __strnlen_sse2
-
-# undef weak_alias
-# define weak_alias(__strnlen, strnlen)
-# undef libc_hidden_builtin_def
-# define libc_hidden_builtin_def(strnlen)
+# ifndef STRLEN
+#  define STRLEN	__strnlen_sse2
+# endif
 #endif
 
-#include "../strnlen.S"
+#define AS_STRNLEN
+#include "strlen-sse2.S"
diff --git a/sysdeps/x86_64/multiarch/wcslen-sse4_1.S b/sysdeps/x86_64/multiarch/wcslen-sse4_1.S
index e306a77..c88e834 100644
--- a/sysdeps/x86_64/multiarch/wcslen-sse4_1.S
+++ b/sysdeps/x86_64/multiarch/wcslen-sse4_1.S
@@ -1,5 +1,5 @@
 #define AS_WCSLEN
-#define strlen	__wcslen_sse4_1
+#define STRLEN	__wcslen_sse4_1
 #define SECTION(p)	p##.sse4.1
 
-#include "strlen-vec.S"
+#include "strlen-sse2.S"
diff --git a/sysdeps/x86_64/multiarch/wcsnlen-sse4_1.S b/sysdeps/x86_64/multiarch/wcsnlen-sse4_1.S
index d2f7dd6..17cdedc 100644
--- a/sysdeps/x86_64/multiarch/wcsnlen-sse4_1.S
+++ b/sysdeps/x86_64/multiarch/wcsnlen-sse4_1.S
@@ -1,6 +1,6 @@
 #define AS_WCSLEN
 #define AS_STRNLEN
-#define strlen	__wcsnlen_sse4_1
+#define STRLEN	__wcsnlen_sse4_1
 #define SECTION(p)	p##.sse4.1
 
-#include "strlen-vec.S"
+#include "strlen-sse2.S"
diff --git a/sysdeps/x86_64/strlen.S b/sysdeps/x86_64/strlen.S
index e1f0b19..c2f5674 100644
--- a/sysdeps/x86_64/strlen.S
+++ b/sysdeps/x86_64/strlen.S
@@ -16,6 +16,7 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include "multiarch/strlen-vec.S"
+#define STRLEN	strlen
+#include "multiarch/strlen-sse2.S"
 
 libc_hidden_builtin_def (strlen)
diff --git a/sysdeps/x86_64/strnlen.S b/sysdeps/x86_64/strnlen.S
index d3c43ac..174970d 100644
--- a/sysdeps/x86_64/strnlen.S
+++ b/sysdeps/x86_64/strnlen.S
@@ -1,6 +1,6 @@
-#define AS_STRNLEN
-#define strlen __strnlen
-#include "strlen.S"
+#define STRLEN __strnlen
+#include "multiarch/strnlen-sse2.S"
 
+libc_hidden_def (__strnlen)
 weak_alias (__strnlen, strnlen);
 libc_hidden_builtin_def (strnlen)