/**************************************************************************** * libs/libc/machine/xtensa/arch_strcpy.S * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include "xtensa_asm.h" #include #include /**************************************************************************** * Public Functions ****************************************************************************/ .section .text .begin schedule .align 4 .literal_position .global strcpy .type strcpy, @function strcpy: ENTRY(16) /* 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: RET(16) /* dst is word-aligned; src is word-aligned. */ .align 4 #if XCHAL_HAVE_LOOPS #if XCHAL_HAVE_DENSITY /* (2 mod 4) alignment for loop instruction */ #else /* (1 mod 4) alignment for loop instruction */ .byte 0 .byte 0 #endif .Laligned: #if XCHAL_HAVE_DENSITY _movi.n a8, 0 # set up for the maximum loop count #else _movi a8, 0 # set up for the maximum loop count #endif 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. */ RET(16) .Lz0: /* Byte 0 is zero. */ #if XCHAL_HAVE_BE movi a8, 0 #endif s8i a8, a10, 0 RET(16) .Lz1: /* Byte 1 is zero. */ #if XCHAL_HAVE_BE extui a8, a8, 16, 16 #endif s16i a8, a10, 0 RET(16) .Lz2: /* Byte 2 is zero. */ #if XCHAL_HAVE_BE extui a8, a8, 16, 16 #endif s16i a8, a10, 0 movi a8, 0 s8i a8, a10, 2 RET(16) #if 1 /* For now just use byte copy loop for the unaligned destination case. */ .align 4 #if XCHAL_HAVE_LOOPS #if XCHAL_HAVE_DENSITY /* (2 mod 4) alignment for loop instruction */ #else /* (1 mod 4) alignment for loop instruction */ .byte 0 .byte 0 #endif #endif .Ldstunaligned: #if XCHAL_HAVE_LOOPS #if XCHAL_HAVE_DENSITY _movi.n a8, 0 # set up for the maximum loop count #else _movi a8, 0 # set up for the maximum loop count #endif 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: RET(16) #else /* 0 */ /* This code is not functional yet. */ .Ldstunaligned: l32i a9, a2, 0 # load word from dst #if XCHAL_HAVE_BE ssa8b a9 # rotate by dst alignment so that src a9, a9, a9 # shift in loop will put back in place ssa8l a9 # shift left by byte*8 #else ssa8l a9 # rotate by dst alignment so that src a9, a9, a9 # shift in loop will put back in place ssa8b a9 # shift left by 32-byte*8 #endif /* dst is word-aligned; src is unaligned. */ .Ldstunalignedloop: l32i a8, a3, 0 # get word from src /* 1-cycle interlock */ bnone a8, a4, .Lu0 # if byte 0 is zero bnone a8, a5, .Lu1 # if byte 1 is zero bnone a8, a6, .Lu2 # if byte 2 is zero src a9, a8, a9 # combine last word and this word s32i a9, a10, 0 # store word to dst bnone a8, a7, .Lu3 # if byte 3 is nonzero, iterate l32i a9, a3, 4 # get word from src addi a3, a3, 8 # advance src pointer bnone a9, a4, .Lu4 # if byte 0 is zero bnone a9, a5, .Lu5 # if byte 1 is zero bnone a9, a6, .Lu6 # if byte 2 is zero src a8, a9, a8 # combine last word and this word s32i a8, a10, 4 # store word to dst addi a10, a10, 8 # advance dst pointer bany a8, a7, .Ldstunalignedloop # if byte 3 is nonzero, iterate /* Byte 7 is zero. */ .Lu7: RET(16) .Lu0: /* Byte 0 is zero. */ #if XCHAL_HAVE_BE movi a8, 0 #endif s8i a8, a10, 0 RET(16) .Lu1: /* Byte 1 is zero. */ #if XCHAL_HAVE_BE extui a8, a8, 16, 16 #endif s16i a8, a10, 0 RET(16) .Lu2: /* Byte 2 is zero. */ s16i a8, a10, 0 movi a8, 0 s8i a8, a10, 2 RET(16) #endif /* 0 */ .end schedule .size strcpy, . - strcpy