diff options
Diffstat (limited to 'libc/string/xtensa/strcpy.S')
| -rw-r--r-- | libc/string/xtensa/strcpy.S | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/libc/string/xtensa/strcpy.S b/libc/string/xtensa/strcpy.S new file mode 100644 index 000000000..108070384 --- /dev/null +++ b/libc/string/xtensa/strcpy.S @@ -0,0 +1,150 @@ +/* Optimized strcpy for Xtensa. + Copyright (C) 2001, 2007 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 + 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, write to the Free + Software Foundation, Inc., 51 Franklin Street - Fifth Floor, + Boston, MA 02110-1301, USA. */ + +#include "../../sysdeps/linux/xtensa/sysdep.h" +#include <bits/xtensa-config.h> + +#ifdef __XTENSA_EB__ +#define MASK0 0xff000000 +#define MASK1 0x00ff0000 +#define MASK2 0x0000ff00 +#define MASK3 0x000000ff +#else +#define MASK0 0x000000ff +#define MASK1 0x0000ff00 +#define MASK2 0x00ff0000 +#define MASK3 0xff000000 +#endif + + .text +ENTRY (strcpy) + /* a2 = dst, a3 = src */ + + mov a10, a2 // leave dst in return value register + movi a4, MASK0 + movi a5, MASK1 + movi a6, MASK2 + movi a7, MASK3 + bbsi.l a3, 0, .Lsrc1mod2 + bbsi.l a3, 1, .Lsrc2mod4 +.Lsrcaligned: + + /* Check if the destination is aligned. */ + movi a8, 3 + bnone a10, a8, .Laligned + + j .Ldstunaligned + +.Lsrc1mod2: // src address is odd + l8ui a8, a3, 0 // get byte 0 + addi a3, a3, 1 // advance src pointer + s8i a8, a10, 0 // store byte 0 + beqz a8, 1f // if byte 0 is zero + addi a10, a10, 1 // advance dst pointer + bbci.l a3, 1, .Lsrcaligned // if src is now word-aligned + +.Lsrc2mod4: // src address is 2 mod 4 + l8ui a8, a3, 0 // get byte 0 + /* 1-cycle interlock */ + s8i a8, a10, 0 // store byte 0 + beqz a8, 1f // if byte 0 is zero + l8ui a8, a3, 1 // get byte 0 + addi a3, a3, 2 // advance src pointer + s8i a8, a10, 1 // store byte 0 + addi a10, a10, 2 // advance dst pointer + bnez a8, .Lsrcaligned +1: retw + + +/* dst is word-aligned; src is word-aligned. */ + + .align 4 +#if XCHAL_HAVE_LOOPS + /* (2 mod 4) alignment for loop instruction */ +.Laligned: + _movi.n a8, 0 // set up for the maximum loop count + loop a8, .Lz3 // loop forever (almost anyway) + l32i a8, a3, 0 // get word from src + addi a3, a3, 4 // advance src pointer + bnone a8, a4, .Lz0 // if byte 0 is zero + bnone a8, a5, .Lz1 // if byte 1 is zero + bnone a8, a6, .Lz2 // if byte 2 is zero + s32i a8, a10, 0 // store word to dst + bnone a8, a7, .Lz3 // if byte 3 is zero + addi a10, a10, 4 // advance dst pointer + +#else /* !XCHAL_HAVE_LOOPS */ + +1: addi a10, a10, 4 // advance dst pointer +.Laligned: + l32i a8, a3, 0 // get word from src + addi a3, a3, 4 // advance src pointer + bnone a8, a4, .Lz0 // if byte 0 is zero + bnone a8, a5, .Lz1 // if byte 1 is zero + bnone a8, a6, .Lz2 // if byte 2 is zero + s32i a8, a10, 0 // store word to dst + bany a8, a7, 1b // if byte 3 is zero +#endif /* !XCHAL_HAVE_LOOPS */ + +.Lz3: /* Byte 3 is zero. */ + retw + +.Lz0: /* Byte 0 is zero. */ +#ifdef __XTENSA_EB__ + movi a8, 0 +#endif + s8i a8, a10, 0 + retw + +.Lz1: /* Byte 1 is zero. */ +#ifdef __XTENSA_EB__ + extui a8, a8, 16, 16 +#endif + s16i a8, a10, 0 + retw + +.Lz2: /* Byte 2 is zero. */ +#ifdef __XTENSA_EB__ + extui a8, a8, 16, 16 +#endif + s16i a8, a10, 0 + movi a8, 0 + s8i a8, a10, 2 + retw + + .align 4 + /* (2 mod 4) alignment for loop instruction */ +.Ldstunaligned: + +#if XCHAL_HAVE_LOOPS + _movi.n a8, 0 // set up for the maximum loop count + loop a8, 2f // loop forever (almost anyway) +#endif +1: l8ui a8, a3, 0 + addi a3, a3, 1 + s8i a8, a10, 0 + addi a10, a10, 1 +#if XCHAL_HAVE_LOOPS + beqz a8, 2f +#else + bnez a8, 1b +#endif +2: retw + +libc_hidden_def (strcpy) |