glibc/sysdeps/ia64/strcat.S

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/* IA-64 assembly version of the standard strcat() function.
This file is part of the GNU C Library.
Copyright (C) 2000, 2001 Free Software Foundation, Inc.
Contributed by Dan Pop <Dan.Pop@cern.ch>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* Return: dest
Inputs:
in0: dest
in1: src
A straightforword implementation: strcpy(dest + strlen(dest), src).
Could be marginally optimised by inlining the code of strcpy() and
strlen(), to avoid the two function calls. OTOH, by not doing that,
we avoid L1I cache pollution (code using strcat() is likely to also
use strcpy() and strlen(), so we already have a copy of these functions
in the cache). */
#include <sysdep.h>
#undef ret
#define src in1
#define dest in0
#define save_b0 loc0
#define save_pfs loc1
#define tmp loc2
#define rc ret0
ENTRY(strcat)
.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
alloc save_pfs = ar.pfs, 2, 3, 2, 0
mov save_b0 = b0
.body
mov out0 = dest
mov tmp = gp ;;
br.call.sptk.many b0 = strlen# ;; // rc = strlen(dest);
mov gp = tmp
add out0 = dest, rc
mov out1 = src
br.call.sptk.many b0 = strcpy# ;; // strcpy(dest + strlen(dest), src)
mov gp = tmp
mov rc = dest
mov b0 = save_b0
mov ar.pfs = save_pfs
br.ret.sptk.many b0
END(strcat)