diff --git a/libc/arch-x86/string/ssse3-strcat-atom.S b/libc/arch-x86/string/ssse3-strcat-atom.S
new file mode 100644
index 0000000..d9b6129
--- /dev/null
+++ b/libc/arch-x86/string/ssse3-strcat-atom.S
@@ -0,0 +1,620 @@
+/*
+Copyright (c) 2011, Intel Corporation
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+    * this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright notice,
+    * this list of conditions and the following disclaimer in the documentation
+    * and/or other materials provided with the distribution.
+
+    * Neither the name of Intel Corporation nor the names of its contributors
+    * may be used to endorse or promote products derived from this software
+    * without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef L
+# define L(label)	.L##label
+#endif
+
+#ifndef cfi_startproc
+# define cfi_startproc			.cfi_startproc
+#endif
+
+#ifndef cfi_endproc
+# define cfi_endproc			.cfi_endproc
+#endif
+
+#ifndef cfi_rel_offset
+# define cfi_rel_offset(reg, off)	.cfi_rel_offset reg, off
+#endif
+
+#ifndef cfi_restore
+# define cfi_restore(reg)		.cfi_restore reg
+#endif
+
+#ifndef cfi_adjust_cfa_offset
+# define cfi_adjust_cfa_offset(off)	.cfi_adjust_cfa_offset off
+#endif
+
+#ifndef cfi_remember_state
+# define cfi_remember_state		.cfi_remember_state
+#endif
+
+#ifndef cfi_restore_state
+# define cfi_restore_state		.cfi_restore_state
+#endif
+
+#ifndef ENTRY
+# define ENTRY(name)			\
+	.type name,  @function; 	\
+	.globl name;			\
+	.p2align 4;			\
+name:					\
+	cfi_startproc
+#endif
+
+#ifndef END
+# define END(name)			\
+	cfi_endproc;			\
+	.size name, .-name
+#endif
+
+#define CFI_PUSH(REG)			\
+  cfi_adjust_cfa_offset (4);		\
+  cfi_rel_offset (REG, 0)
+
+#define CFI_POP(REG)			\
+  cfi_adjust_cfa_offset (-4);		\
+  cfi_restore (REG)
+
+#define PUSH(REG)	pushl REG; CFI_PUSH (REG)
+#define POP(REG)	popl REG; CFI_POP (REG)
+
+#ifndef STRCAT
+# define STRCAT	strcat
+#endif
+
+#define PARMS	4
+#define STR1	PARMS+4
+#define STR2	STR1+4
+
+#ifdef USE_AS_STRNCAT
+# define LEN	STR2+8
+#endif
+
+#define USE_AS_STRCAT
+
+	.section .text.ssse3,"ax",@progbits
+ENTRY (STRCAT)
+	PUSH	(%edi)
+	mov	STR1(%esp), %edi
+	mov	%edi, %edx
+
+#define RETURN	jmp	L(StrcpyAtom)
+#include "sse2-strlen-atom.S"
+
+L(StrcpyAtom):
+	mov	STR2(%esp), %ecx
+	lea	(%edi, %eax), %edx
+#ifdef USE_AS_STRNCAT
+	PUSH	(%ebx)
+	mov	LEN(%esp), %ebx
+	test	%ebx, %ebx
+	jz	L(StrncatExit0)
+	cmp	$8, %ebx
+	jbe	L(StrncpyExit8Bytes)
+#endif
+	cmpb	$0, (%ecx)
+	jz	L(Exit1)
+	cmpb	$0, 1(%ecx)
+	jz	L(Exit2)
+	cmpb	$0, 2(%ecx)
+	jz	L(Exit3)
+	cmpb	$0, 3(%ecx)
+	jz	L(Exit4)
+	cmpb	$0, 4(%ecx)
+	jz	L(Exit5)
+	cmpb	$0, 5(%ecx)
+	jz	L(Exit6)
+	cmpb	$0, 6(%ecx)
+	jz	L(Exit7)
+	cmpb	$0, 7(%ecx)
+	jz	L(Exit8)
+	cmpb	$0, 8(%ecx)
+	jz	L(Exit9)
+#ifdef USE_AS_STRNCAT
+	cmp	$16, %ebx
+	jb	L(StrncpyExit15Bytes)
+#endif
+	cmpb	$0, 9(%ecx)
+	jz	L(Exit10)
+	cmpb	$0, 10(%ecx)
+	jz	L(Exit11)
+	cmpb	$0, 11(%ecx)
+	jz	L(Exit12)
+	cmpb	$0, 12(%ecx)
+	jz	L(Exit13)
+	cmpb	$0, 13(%ecx)
+	jz	L(Exit14)
+	cmpb	$0, 14(%ecx)
+	jz	L(Exit15)
+	cmpb	$0, 15(%ecx)
+	jz	L(Exit16)
+#ifdef USE_AS_STRNCAT
+	cmp	$16, %ebx
+	je	L(StrncatExit16)
+
+# define RETURN1	POP (%ebx); POP (%edi);	ret; \
+	CFI_PUSH (%ebx); CFI_PUSH (%edi)
+# define USE_AS_STRNCPY
+#else
+# define RETURN1	POP(%edi); ret; CFI_PUSH(%edi)
+#endif
+#include "ssse3-strcpy-atom.S"
+
+	.p2align 4
+L(CopyFrom1To16Bytes):
+	add	%esi, %edx
+	add	%esi, %ecx
+
+	POP	(%esi)
+	test	%al, %al
+	jz	L(ExitHigh)
+	test	$0x01, %al
+	jnz	L(Exit1)
+	test	$0x02, %al
+	jnz	L(Exit2)
+	test	$0x04, %al
+	jnz	L(Exit3)
+	test	$0x08, %al
+	jnz	L(Exit4)
+	test	$0x10, %al
+	jnz	L(Exit5)
+	test	$0x20, %al
+	jnz	L(Exit6)
+	test	$0x40, %al
+	jnz	L(Exit7)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(ExitHigh):
+	test	$0x01, %ah
+	jnz	L(Exit9)
+	test	$0x02, %ah
+	jnz	L(Exit10)
+	test	$0x04, %ah
+	jnz	L(Exit11)
+	test	$0x08, %ah
+	jnz	L(Exit12)
+	test	$0x10, %ah
+	jnz	L(Exit13)
+	test	$0x20, %ah
+	jnz	L(Exit14)
+	test	$0x40, %ah
+	jnz	L(Exit15)
+	movlpd	(%ecx), %xmm0
+	movlpd	8(%ecx), %xmm1
+	movlpd	%xmm0, (%edx)
+	movlpd	%xmm1, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit1):
+	movb	%bh, 1(%edx)
+L(Exit1):
+	movb	(%ecx), %al
+	movb	%al, (%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit2):
+	movb	%bh, 2(%edx)
+L(Exit2):
+	movw	(%ecx), %ax
+	movw	%ax, (%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit3):
+	movb	%bh, 3(%edx)
+L(Exit3):
+	movw	(%ecx), %ax
+	movw	%ax, (%edx)
+	movb	2(%ecx), %al
+	movb	%al, 2(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit4):
+	movb	%bh, 4(%edx)
+L(Exit4):
+	movl	(%ecx), %eax
+	movl	%eax, (%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit5):
+	movb	%bh, 5(%edx)
+L(Exit5):
+	movl	(%ecx), %eax
+	movl	%eax, (%edx)
+	movb	4(%ecx), %al
+	movb	%al, 4(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit6):
+	movb	%bh, 6(%edx)
+L(Exit6):
+	movl	(%ecx), %eax
+	movl	%eax, (%edx)
+	movw	4(%ecx), %ax
+	movw	%ax, 4(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit7):
+	movb	%bh, 7(%edx)
+L(Exit7):
+	movl	(%ecx), %eax
+	movl	%eax, (%edx)
+	movl	3(%ecx), %eax
+	movl	%eax, 3(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit8):
+	movb	%bh, 8(%edx)
+L(Exit8):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit9):
+	movb	%bh, 9(%edx)
+L(Exit9):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movb	8(%ecx), %al
+	movb	%al, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit10):
+	movb	%bh, 10(%edx)
+L(Exit10):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movw	8(%ecx), %ax
+	movw	%ax, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit11):
+	movb	%bh, 11(%edx)
+L(Exit11):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movl	7(%ecx), %eax
+	movl	%eax, 7(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit12):
+	movb	%bh, 12(%edx)
+L(Exit12):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movl	8(%ecx), %eax
+	movl	%eax, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit13):
+	movb	%bh, 13(%edx)
+L(Exit13):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movlpd	5(%ecx), %xmm0
+	movlpd	%xmm0, 5(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit14):
+	movb	%bh, 14(%edx)
+L(Exit14):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movlpd	6(%ecx), %xmm0
+	movlpd	%xmm0, 6(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit15):
+	movb	%bh, 15(%edx)
+L(Exit15):
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movlpd	7(%ecx), %xmm0
+	movlpd	%xmm0, 7(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit16):
+	movb	%bh, 16(%edx)
+L(Exit16):
+	movlpd	(%ecx), %xmm0
+	movlpd	8(%ecx), %xmm1
+	movlpd	%xmm0, (%edx)
+	movlpd	%xmm1, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+#ifdef USE_AS_STRNCPY
+
+	CFI_PUSH(%esi)
+
+	.p2align 4
+L(CopyFrom1To16BytesCase2):
+	add	$16, %ebx
+	add	%esi, %ecx
+	lea	(%esi, %edx), %esi
+	lea	-9(%ebx), %edx
+	and	$1<<7, %dh
+	or	%al, %dh
+	lea	(%esi), %edx
+	POP	(%esi)
+	jz	L(ExitHighCase2)
+
+	test	$0x01, %al
+	jnz	L(Exit1)
+	cmp	$1, %ebx
+	je	L(StrncatExit1)
+	test	$0x02, %al
+	jnz	L(Exit2)
+	cmp	$2, %ebx
+	je	L(StrncatExit2)
+	test	$0x04, %al
+	jnz	L(Exit3)
+	cmp	$3, %ebx
+	je	L(StrncatExit3)
+	test	$0x08, %al
+	jnz	L(Exit4)
+	cmp	$4, %ebx
+	je	L(StrncatExit4)
+	test	$0x10, %al
+	jnz	L(Exit5)
+	cmp	$5, %ebx
+	je	L(StrncatExit5)
+	test	$0x20, %al
+	jnz	L(Exit6)
+	cmp	$6, %ebx
+	je	L(StrncatExit6)
+	test	$0x40, %al
+	jnz	L(Exit7)
+	cmp	$7, %ebx
+	je	L(StrncatExit7)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	lea	7(%edx), %eax
+	cmpb	$1, (%eax)
+	sbb	$-1, %eax
+	xor	%cl, %cl
+	movb	%cl, (%eax)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(ExitHighCase2):
+	test	$0x01, %ah
+	jnz	L(Exit9)
+	cmp	$9, %ebx
+	je	L(StrncatExit9)
+	test	$0x02, %ah
+	jnz	L(Exit10)
+	cmp	$10, %ebx
+	je	L(StrncatExit10)
+	test	$0x04, %ah
+	jnz	L(Exit11)
+	cmp	$11, %ebx
+	je	L(StrncatExit11)
+	test	$0x8, %ah
+	jnz	L(Exit12)
+	cmp	$12, %ebx
+	je	L(StrncatExit12)
+	test	$0x10, %ah
+	jnz	L(Exit13)
+	cmp	$13, %ebx
+	je	L(StrncatExit13)
+	test	$0x20, %ah
+	jnz	L(Exit14)
+	cmp	$14, %ebx
+	je	L(StrncatExit14)
+	test	$0x40, %ah
+	jnz	L(Exit15)
+	cmp	$15, %ebx
+	je	L(StrncatExit15)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movlpd	8(%ecx), %xmm1
+	movlpd	%xmm1, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	CFI_PUSH(%esi)
+
+L(CopyFrom1To16BytesCase2OrCase3):
+	test	%eax, %eax
+	jnz	L(CopyFrom1To16BytesCase2)
+
+	.p2align 4
+L(CopyFrom1To16BytesCase3):
+	add	$16, %ebx
+	add	%esi, %edx
+	add	%esi, %ecx
+
+	POP	(%esi)
+
+	cmp	$8, %ebx
+	ja	L(ExitHighCase3)
+	cmp	$1, %ebx
+	je	L(StrncatExit1)
+	cmp	$2, %ebx
+	je	L(StrncatExit2)
+	cmp	$3, %ebx
+	je	L(StrncatExit3)
+	cmp	$4, %ebx
+	je	L(StrncatExit4)
+	cmp	$5, %ebx
+	je	L(StrncatExit5)
+	cmp	$6, %ebx
+	je	L(StrncatExit6)
+	cmp	$7, %ebx
+	je	L(StrncatExit7)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movb	%bh, 8(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(ExitHighCase3):
+	cmp	$9, %ebx
+	je	L(StrncatExit9)
+	cmp	$10, %ebx
+	je	L(StrncatExit10)
+	cmp	$11, %ebx
+	je	L(StrncatExit11)
+	cmp	$12, %ebx
+	je	L(StrncatExit12)
+	cmp	$13, %ebx
+	je	L(StrncatExit13)
+	cmp	$14, %ebx
+	je	L(StrncatExit14)
+	cmp	$15, %ebx
+	je	L(StrncatExit15)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movlpd	8(%ecx), %xmm1
+	movlpd	%xmm1, 8(%edx)
+	movb	%bh, 16(%edx)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncatExit0):
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncpyExit15Bytes):
+	cmp	$9, %ebx
+	je	L(StrncatExit9)
+	cmpb	$0, 9(%ecx)
+	jz	L(Exit10)
+	cmp	$10, %ebx
+	je	L(StrncatExit10)
+	cmpb	$0, 10(%ecx)
+	jz	L(Exit11)
+	cmp	$11, %ebx
+	je	L(StrncatExit11)
+	cmpb	$0, 11(%ecx)
+	jz	L(Exit12)
+	cmp	$12, %ebx
+	je	L(StrncatExit12)
+	cmpb	$0, 12(%ecx)
+	jz	L(Exit13)
+	cmp	$13, %ebx
+	je	L(StrncatExit13)
+	cmpb	$0, 13(%ecx)
+	jz	L(Exit14)
+	cmp	$14, %ebx
+	je	L(StrncatExit14)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	movlpd	7(%ecx), %xmm0
+	movlpd	%xmm0, 7(%edx)
+	lea	14(%edx), %eax
+	cmpb	$1, (%eax)
+	sbb	$-1, %eax
+	movb	%bh, (%eax)
+	movl	%edi, %eax
+	RETURN1
+
+	.p2align 4
+L(StrncpyExit8Bytes):
+	cmpb	$0, (%ecx)
+	jz	L(Exit1)
+	cmp	$1, %ebx
+	je	L(StrncatExit1)
+	cmpb	$0, 1(%ecx)
+	jz	L(Exit2)
+	cmp	$2, %ebx
+	je	L(StrncatExit2)
+	cmpb	$0, 2(%ecx)
+	jz	L(Exit3)
+	cmp	$3, %ebx
+	je	L(StrncatExit3)
+	cmpb	$0, 3(%ecx)
+	jz	L(Exit4)
+	cmp	$4, %ebx
+	je	L(StrncatExit4)
+	cmpb	$0, 4(%ecx)
+	jz	L(Exit5)
+	cmp	$5, %ebx
+	je	L(StrncatExit5)
+	cmpb	$0, 5(%ecx)
+	jz	L(Exit6)
+	cmp	$6, %ebx
+	je	L(StrncatExit6)
+	cmpb	$0, 6(%ecx)
+	jz	L(Exit7)
+	cmp	$7, %ebx
+	je	L(StrncatExit7)
+	movlpd	(%ecx), %xmm0
+	movlpd	%xmm0, (%edx)
+	lea	7(%edx), %eax
+	cmpb	$1, (%eax)
+	sbb	$-1, %eax
+	movb	%bh, (%eax)
+	movl	%edi, %eax
+	RETURN1
+
+#endif
+END (STRCAT)