diff options
Diffstat (limited to 'lib/libc/amd64/string/strcat.S')
| -rw-r--r-- | lib/libc/amd64/string/strcat.S | 47 |
1 files changed, 42 insertions, 5 deletions
diff --git a/lib/libc/amd64/string/strcat.S b/lib/libc/amd64/string/strcat.S index 0834408acfb7..081e98840cee 100644 --- a/lib/libc/amd64/string/strcat.S +++ b/lib/libc/amd64/string/strcat.S @@ -1,6 +1,14 @@ -/* - * Written by J.T. Conklin <jtc@acorntoolworks.com> - * Public domain. +/*- + * Copyright (c) 2023, The FreeBSD Foundation + * + * SPDX-License-Expression: BSD-2-Clause + * + * Portions of this software were developed by Robert Clausecker + * <fuz@FreeBSD.org> under sponsorship from the FreeBSD Foundation. + * + * Adapted from NetBSD's common/lib/libc/arch/x86_64/string/strcat.S + * written by J.T. Conklin <jtc@acorntoolworks.com> + * that was originally dedicated to the public domain */ #include <machine/asm.h> @@ -8,7 +16,14 @@ RCSID("$NetBSD: strcat.S,v 1.4 2004/07/26 18:51:21 drochner Exp $") #endif -ENTRY(strcat) +#include "amd64_archlevel.h" + +ARCHFUNCS(strcat) + ARCHFUNC(strcat, scalar) + ARCHFUNC(strcat, baseline) +ENDARCHFUNCS(strcat) + +ARCHENTRY(strcat, scalar) movq %rdi,%rax movabsq $0x0101010101010101,%r8 movabsq $0x8080808080808080,%r9 @@ -161,6 +176,28 @@ ENTRY(strcat) .Ldone: ret -END(strcat) +ARCHEND(strcat, scalar) + +/* + * Call into strlen + strcpy if we have any SIMD at all. + * The scalar implementation above is better for the scalar + * case as it avoids the function call overhead, but pessimal + * if we could call SIMD routines instead. + */ +ARCHENTRY(strcat, baseline) + push %rbp + mov %rsp, %rbp + push %rsi + push %rbx + mov %rdi, %rbx # remember destination for later + call CNAME(strlen) # strlen(dest) + mov -8(%rbp), %rsi + lea (%rbx, %rax, 1), %rdi # dest + strlen(dest) + call CNAME(__stpcpy) # stpcpy(dest + strlen(dest), src) + mov %rbx, %rax # return dest + pop %rbx + leave + ret +ARCHEND(strcat, baseline) .section .note.GNU-stack,"",%progbits |