diff mbox

x86-64: Update strlen.S to support wcslen/wcsnlen

Message ID 20170520135619.GA17481@gmail.com
State New, archived
Headers

Commit Message

H.J. Lu May 20, 2017, 1:56 p.m. UTC 
  The difference between strlen and wcslen is byte vs int.  We can
replace pminub and pcmpeqb with pminud and pcmpeqd to turn strlen
into wcslen.  Tested on Ivy Bridge with benchtests/bench-wcslen.c,
the new strlen based wcslen is as fast as the old wcslen.

OK for master?

H.J.
---
	* sysdeps/x86_64/strlen.S (PMINU): New.
	(PCMPEQ): Likewise.
	(SHIFT_RETURN): Likewise.
	(FIND_ZERO): Replace pcmpeqb with PCMPEQ.
	(strlen): Add SHIFT_RETURN before ret.  Replace pcmpeqb and
	pminub with PCMPEQ and PMINU.
	* sysdeps/x86_64/wcslen.S: Define AS_WCSLEN and strlen.
	Include "strlen.S".
	* sysdeps/x86_64/wcsnlen.S: New file.
---
 sysdeps/x86_64/strlen.S  |  61 +++++++-----
 sysdeps/x86_64/wcslen.S  | 238 +----------------------------------------------
 sysdeps/x86_64/wcsnlen.S |   7 ++
 3 files changed, 50 insertions(+), 256 deletions(-)
 create mode 100644 sysdeps/x86_64/wcsnlen.S
diff mbox

Patch

diff --git a/sysdeps/x86_64/strlen.S b/sysdeps/x86_64/strlen.S
index 5896e6b9..b5ab117 100644
--- a/sysdeps/x86_64/strlen.S
+++ b/sysdeps/x86_64/strlen.S
@@ -1,4 +1,4 @@ 
-/* SSE2 version of strlen.
+/* SSE2 version of strlen/wcslen.
    Copyright (C) 2012-2017 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -18,6 +18,16 @@ 
 
 #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
+
 /* Long lived register in strlen(s), strnlen(s, n) are:
 
 	%xmm3 - zero
@@ -32,10 +42,10 @@  ENTRY(strlen)
 
 /* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx.  */
 #define FIND_ZERO	\
-	pcmpeqb	(%rax), %xmm0;	\
-	pcmpeqb	16(%rax), %xmm1;	\
-	pcmpeqb	32(%rax), %xmm2;	\
-	pcmpeqb	48(%rax), %xmm3;	\
+	PCMPEQ	(%rax), %xmm0;	\
+	PCMPEQ	16(%rax), %xmm1;	\
+	PCMPEQ	32(%rax), %xmm2;	\
+	PCMPEQ	48(%rax), %xmm3;	\
 	pmovmskb	%xmm0, %esi;	\
 	pmovmskb	%xmm1, %edx;	\
 	pmovmskb	%xmm2, %r8d;	\
@@ -54,6 +64,9 @@  ENTRY(strlen)
 	xor	%rax, %rax
 	ret
 L(n_nonzero):
+# ifdef AS_WCSLEN
+	shlq	$2, %rsi
+# endif
 
 /* Initialize long lived registers.  */
 
@@ -96,6 +109,7 @@  L(n_nonzero):
 	test	%rdx, %rdx;	\
 	je	L(lab);	\
 	bsfq	%rdx, %rax;	\
+	SHIFT_RETURN;		\
 	ret
 
 #ifdef AS_STRNLEN
@@ -104,19 +118,20 @@  L(n_nonzero):
 #else
 	/* Test first 16 bytes unaligned.  */
 	movdqu	(%rax), %xmm4
-	pcmpeqb	%xmm0, %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
-	pcmpeqb 16(%rax), %xmm1
-	pcmpeqb 32(%rax), %xmm2
-	pcmpeqb 48(%rax), %xmm3
+	PCMPEQ 16(%rax), %xmm1
+	PCMPEQ 32(%rax), %xmm2
+	PCMPEQ 48(%rax), %xmm3
 	pmovmskb	%xmm1, %edx
 	pmovmskb	%xmm2, %r8d
 	pmovmskb	%xmm3, %ecx
@@ -145,6 +160,7 @@  L(strnlen_ret):
 	test	%rdx, %rdx
 	je	L(loop_init)
 	bsfq	%rdx, %rax
+	SHIFT_RETURN
 	ret
 #endif
 	.p2align 4
@@ -161,10 +177,10 @@  L(loop):
 	je	L(exit_end)
 
 	movdqa	(%rax), %xmm0
-	pminub	16(%rax), %xmm0
-	pminub	32(%rax), %xmm0
-	pminub	48(%rax), %xmm0
-	pcmpeqb	%xmm3, %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)
@@ -182,6 +198,7 @@  L(first):
 	bsfq	%rdx, %rdx
 	addq	%rdx, %rax
 	subq	%rdi, %rax
+	SHIFT_RETURN
 	ret
 
 	.p2align 4
@@ -192,6 +209,7 @@  L(exit):
 	bsfq	%rdx, %rdx
 	addq	%rdx, %rax
 	subq	%rdi, %rax
+	SHIFT_RETURN
 	ret
 
 #else
@@ -201,10 +219,10 @@  L(exit):
 L(loop):
 
 	movdqa	64(%rax), %xmm0
-	pminub	80(%rax), %xmm0
-	pminub	96(%rax), %xmm0
-	pminub	112(%rax), %xmm0
-	pcmpeqb	%xmm3, %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)
@@ -212,10 +230,10 @@  L(loop):
 	subq	$-128, %rax
 
 	movdqa	(%rax), %xmm0
-	pminub	16(%rax), %xmm0
-	pminub	32(%rax), %xmm0
-	pminub	48(%rax), %xmm0
-	pcmpeqb	%xmm3, %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)
@@ -231,6 +249,7 @@  L(exit0):
 	bsfq	%rdx, %rdx
 	addq	%rdx, %rax
 	subq	%rdi, %rax
+	SHIFT_RETURN
 	ret
 
 #endif
diff --git a/sysdeps/x86_64/wcslen.S b/sysdeps/x86_64/wcslen.S
index c6081a4..88ecdb2 100644
--- a/sysdeps/x86_64/wcslen.S
+++ b/sysdeps/x86_64/wcslen.S
@@ -1,238 +1,6 @@ 
-/* Optimized wcslen for x86-64 with SSE2.
-   Copyright (C) 2011-2017 Free Software Foundation, Inc.
-   Contributed by Intel Corporation.
-   This file is part of the GNU C Library.
+#define AS_WCSLEN
+#define strlen	__wcslen
 
-   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/>.  */
-
-#include <sysdep.h>
-
-	.text
-ENTRY (__wcslen)
-	cmpl	$0, (%rdi)
-	jz	L(exit_tail0)
-	cmpl	$0, 4(%rdi)
-	jz	L(exit_tail1)
-	cmpl	$0, 8(%rdi)
-	jz	L(exit_tail2)
-	cmpl	$0, 12(%rdi)
-	jz	L(exit_tail3)
-	cmpl	$0, 16(%rdi)
-	jz	L(exit_tail4)
-	cmpl	$0, 20(%rdi)
-	jz	L(exit_tail5)
-	cmpl	$0, 24(%rdi)
-	jz	L(exit_tail6)
-	cmpl	$0, 28(%rdi)
-	jz	L(exit_tail7)
-
-	pxor	%xmm0, %xmm0
-
-	lea	32(%rdi), %rax
-	lea	16(%rdi), %rcx
-	and	$-16, %rax
-
-	pcmpeqd	(%rax), %xmm0
-	pmovmskb %xmm0, %edx
-	pxor	%xmm1, %xmm1
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm1
-	pmovmskb %xmm1, %edx
-	pxor	%xmm2, %xmm2
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm2
-	pmovmskb %xmm2, %edx
-	pxor	%xmm3, %xmm3
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm0
-	pmovmskb %xmm0, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm1
-	pmovmskb %xmm1, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm2
-	pmovmskb %xmm2, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm0
-	pmovmskb %xmm0, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm1
-	pmovmskb %xmm1, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm2
-	pmovmskb %xmm2, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	pcmpeqd	(%rax), %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	16(%rax), %rax
-	jnz	L(exit)
-
-	and	$-0x40, %rax
-
-	.p2align 4
-L(aligned_64_loop):
-	movaps	(%rax), %xmm0
-	movaps	16(%rax), %xmm1
-	movaps	32(%rax), %xmm2
-	movaps	48(%rax), %xmm6
-
-	pminub	%xmm1, %xmm0
-	pminub	%xmm6, %xmm2
-	pminub	%xmm0, %xmm2
-	pcmpeqd	%xmm3, %xmm2
-	pmovmskb %xmm2, %edx
-	test	%edx, %edx
-	lea	64(%rax), %rax
-	jz	L(aligned_64_loop)
-
-	pcmpeqd	-64(%rax), %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	48(%rcx), %rcx
-	jnz	L(exit)
-
-	pcmpeqd	%xmm1, %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	-16(%rcx), %rcx
-	jnz	L(exit)
-
-	pcmpeqd	-32(%rax), %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	-16(%rcx), %rcx
-	jnz	L(exit)
-
-	pcmpeqd	%xmm6, %xmm3
-	pmovmskb %xmm3, %edx
-	test	%edx, %edx
-	lea	-16(%rcx), %rcx
-	jnz	L(exit)
-
-	jmp	L(aligned_64_loop)
-
-	.p2align 4
-L(exit):
-	sub	%rcx, %rax
-	shr	$2, %rax
-	test	%dl, %dl
-	jz	L(exit_high)
-
-	mov	%dl, %cl
-	and	$15, %cl
-	jz	L(exit_1)
-	ret
-
-	.p2align 4
-L(exit_high):
-	mov	%dh, %ch
-	and	$15, %ch
-	jz	L(exit_3)
-	add	$2, %rax
-	ret
-
-	.p2align 4
-L(exit_1):
-	add	$1, %rax
-	ret
-
-	.p2align 4
-L(exit_3):
-	add	$3, %rax
-	ret
-
-	.p2align 4
-L(exit_tail0):
-	xor	%rax, %rax
-	ret
-
-	.p2align 4
-L(exit_tail1):
-	mov	$1, %rax
-	ret
-
-	.p2align 4
-L(exit_tail2):
-	mov	$2, %rax
-	ret
-
-	.p2align 4
-L(exit_tail3):
-	mov	$3, %rax
-	ret
-
-	.p2align 4
-L(exit_tail4):
-	mov	$4, %rax
-	ret
-
-	.p2align 4
-L(exit_tail5):
-	mov	$5, %rax
-	ret
-
-	.p2align 4
-L(exit_tail6):
-	mov	$6, %rax
-	ret
-
-	.p2align 4
-L(exit_tail7):
-	mov	$7, %rax
-	ret
-
-END (__wcslen)
+#include "strlen.S"
 
 weak_alias(__wcslen, wcslen)
diff --git a/sysdeps/x86_64/wcsnlen.S b/sysdeps/x86_64/wcsnlen.S
new file mode 100644
index 0000000..968bb69
--- /dev/null
+++ b/sysdeps/x86_64/wcsnlen.S
@@ -0,0 +1,7 @@ 
+#define AS_WCSLEN
+#define AS_STRNLEN
+#define strlen	__wcsnlen
+
+#include "strlen.S"
+
+weak_alias(__wcsnlen, wcsnlen)