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authorH.J. Lu <hjl.tools@gmail.com>2021-06-22 20:42:10 -0700
committerH.J. Lu <hjl.tools@gmail.com>2021-06-23 10:24:35 -0700
commita0db678071c60b6c47c468d231dd0b3694ba7a98 (patch)
tree33afd951b9be6fe9e189170eafd8b0d01ff96717 /sysdeps/x86_64/strlen.S
parent30adcf5adb40293654f77ebd443468a6f6fffc2a (diff)
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x86-64: Move strlen.S to multiarch/strlen-vec.S
Since strlen.S contains SSE2 version of strlen/strnlen and SSE4.1
version of wcslen/wcsnlen, move strlen.S to multiarch/strlen-vec.S
and include multiarch/strlen-vec.S from SSE2 and SSE4.1 variants.
This also removes the unused symbols, __GI___strlen_sse2 and
__GI___wcsnlen_sse4_1.
Diffstat (limited to 'sysdeps/x86_64/strlen.S')
-rw-r--r--sysdeps/x86_64/strlen.S243
1 files changed, 3 insertions, 240 deletions
diff --git a/sysdeps/x86_64/strlen.S b/sysdeps/x86_64/strlen.S
index d223ea1700..8422c15cc8 100644
--- a/sysdeps/x86_64/strlen.S
+++ b/sysdeps/x86_64/strlen.S
@@ -1,5 +1,5 @@
-/* SSE2 version of strlen/wcslen.
-   Copyright (C) 2012-2021 Free Software Foundation, Inc.
+/* SSE2 version of strlen.
+   Copyright (C) 2021 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
@@ -16,243 +16,6 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <sysdep.h>
+#include "multiarch/strlen-vec.S"
 
-#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
-
-/* Long lived register in strlen(s), strnlen(s, n) are:
-
-	%xmm3 - zero
-	%rdi   - s
-	%r10  (s+n) & (~(64-1))
-	%r11   s+n
-*/
-
-
-.text
-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
-	shl	$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)
 libc_hidden_builtin_def (strlen)