/* 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 #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 /* Do not use .literal_position in the ENTRY macro. */ #undef LITERAL_POSITION #define LITERAL_POSITION .text .align 4 .literal_position __strncpy_aux: .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 addi a4, a4, -1 // decrement n beqz a4, .Lret // if n is zero addi a10, a10, 1 // advance dst pointer beqz a8, .Lfill // if byte 0 is zero 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 addi a4, a4, -1 // decrement n s8i a8, a10, 0 // store byte 0 beqz a4, .Lret // if n is zero addi a10, a10, 1 // advance dst pointer beqz a8, .Lfill // if byte 0 is zero l8ui a8, a3, 1 // get byte 0 addi a3, a3, 2 // advance src pointer s8i a8, a10, 0 // store byte 0 addi a4, a4, -1 // decrement n beqz a4, .Lret // if n is zero addi a10, a10, 1 // advance dst pointer bnez a8, .Lsrcaligned j .Lfill .Lret: retw ENTRY (strncpy) /* a2 = dst, a3 = src */ mov a10, a2 // leave dst in return value register beqz a4, .Lret // if n is zero movi a11, 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 /* Fill the dst with zeros -- n is at least 1. */ .Lfill: movi a9, 0 bbsi.l a10, 0, .Lfill1mod2 bbsi.l a10, 1, .Lfill2mod4 .Lfillaligned: blti a4, 4, .Lfillcleanup /* Loop filling complete words with zero. */ #if XCHAL_HAVE_LOOPS srai a8, a4, 2 loop a8, 1f s32i a9, a10, 0 addi a10, a10, 4 1: slli a8, a8, 2 sub a4, a4, a8 #else /* !XCHAL_HAVE_LOOPS */ 1: s32i a9, a10, 0 addi a10, a10, 4 addi a4, a4, -4 bgei a4, 4, 1b #endif /* !XCHAL_HAVE_LOOPS */ beqz a4, 2f .Lfillcleanup: /* Fill leftover (1 to 3) bytes with zero. */ s8i a9, a10, 0 // store byte 0 addi a4, a4, -1 // decrement n addi a10, a10, 1 bnez a4, .Lfillcleanup 2: retw .Lfill1mod2: // dst address is odd s8i a9, a10, 0 // store byte 0 addi a4, a4, -1 // decrement n beqz a4, 2b // if n is zero addi a10, a10, 1 // advance dst pointer bbci.l a10, 1, .Lfillaligned // if dst is now word-aligned .Lfill2mod4: // dst address is 2 mod 4 s8i a9, a10, 0 // store byte 0 addi a4, a4, -1 // decrement n beqz a4, 2b // if n is zero s8i a9, a10, 1 // store byte 1 addi a4, a4, -1 // decrement n beqz a4, 2b // if n is zero addi a10, a10, 2 // advance dst pointer j .Lfillaligned /* dst is word-aligned; src is word-aligned; n is at least 1. */ .align 4 /* (2 mod 4) alignment for loop instruction */ .Laligned: #if XCHAL_HAVE_LOOPS _movi.n a8, 0 // set up for the maximum loop count loop a8, 1f // loop forever (almost anyway) blti a4, 5, .Ldstunaligned // n is near limit; do one at a time l32i a8, a3, 0 // get word from src addi a3, a3, 4 // advance src pointer bnone a8, a11, .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 addi a4, a4, -4 // decrement n addi a10, a10, 4 // advance dst pointer bnone a8, a7, .Lfill // if byte 3 is zero 1: #else /* !XCHAL_HAVE_LOOPS */ 1: blti a4, 5, .Ldstunaligned // n is near limit; do one at a time l32i a8, a3, 0 // get word from src addi a3, a3, 4 // advance src pointer bnone a8, a11, .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 addi a4, a4, -4 // decrement n addi a10, a10, 4 // advance dst pointer bany a8, a7, 1b // no zeroes #endif /* !XCHAL_HAVE_LOOPS */ j .Lfill .Lz0: /* Byte 0 is zero. */ #ifdef __XTENSA_EB__ movi a8, 0 #endif s8i a8, a10, 0 addi a4, a4, -1 // decrement n addi a10, a10, 1 // advance dst pointer j .Lfill .Lz1: /* Byte 1 is zero. */ #ifdef __XTENSA_EB__ extui a8, a8, 16, 16 #endif s16i a8, a10, 0 addi a4, a4, -2 // decrement n addi a10, a10, 2 // advance dst pointer j .Lfill .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 addi a4, a4, -3 // decrement n addi a10, a10, 3 // advance dst pointer j .Lfill .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 a4, a4, -1 beqz a4, 3f addi a10, a10, 1 #if XCHAL_HAVE_LOOPS beqz a8, 2f #else bnez a8, 1b #endif 2: j .Lfill 3: retw libc_hidden_def (strncpy)