/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * * Copyright (C) 2002, 2003 Free Software Foundation, Inc. * This file was originally part of the GNU C Library * Contributed to glibc by Hartvig Ekner , 2002 * Adapted for Rockbox by Maurus Cuelenaere, 2009 * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include "config.h" #include "mips.h" /* void *memcpy(void *s1, const void *s2, size_t n); */ #ifdef ROCKBOX_BIG_ENDIAN # define LWHI lwl /* high part is left in big-endian */ # define SWHI swl /* high part is left in big-endian */ # define LWLO lwr /* low part is right in big-endian */ # define SWLO swr /* low part is right in big-endian */ #else # define LWHI lwr /* high part is right in little-endian */ # define SWHI swr /* high part is right in little-endian */ # define LWLO lwl /* low part is left in little-endian */ # define SWLO swl /* low part is left in little-endian */ #endif .section .icode, "ax", %progbits .global memcpy .type memcpy, %function .global mempcpy .type mempcpy, %function .set noreorder mempcpy: slti t0, a2, 8 # Less than 8? bne t0, zero, last8 addu v0, a0, a2 # exit value = s1 + n b 1f xor t0, a1, a0 # Find a0/a1 displacement (fill delay) memcpy: slti t0, a2, 8 # Less than 8? bne t0, zero, last8 move v0, a0 # Setup exit value before too late xor t0, a1, a0 # Find a0/a1 displacement 1: andi t0, 0x3 bne t0, zero, shift # Go handle the unaligned case subu t1, zero, a1 andi t1, 0x3 # a0/a1 are aligned, but are we beq t1, zero, chk8w # starting in the middle of a word? subu a2, t1 LWHI t0, 0(a1) # Yes we are... take care of that addu a1, t1 SWHI t0, 0(a0) addu a0, t1 chk8w: andi t0, a2, 0x1f # 32 or more bytes left? beq t0, a2, chk1w subu a3, a2, t0 # Yes addu a3, a1 # a3 = end address of loop move a2, t0 # a2 = what will be left after loop lop8w: lw t0, 0(a1) # Loop taking 8 words at a time lw t1, 4(a1) lw t2, 8(a1) lw t3, 12(a1) lw t4, 16(a1) lw t5, 20(a1) lw t6, 24(a1) lw t7, 28(a1) addiu a0, 32 addiu a1, 32 sw t0, -32(a0) sw t1, -28(a0) sw t2, -24(a0) sw t3, -20(a0) sw t4, -16(a0) sw t5, -12(a0) sw t6, -8(a0) bne a1, a3, lop8w sw t7, -4(a0) chk1w: andi t0, a2, 0x3 # 4 or more bytes left? beq t0, a2, last8 subu a3, a2, t0 # Yes, handle them one word at a time addu a3, a1 # a3 again end address move a2, t0 lop1w: lw t0, 0(a1) addiu a0, 4 addiu a1, 4 bne a1, a3, lop1w sw t0, -4(a0) last8: blez a2, lst8e # Handle last 8 bytes, one at a time addu a3, a2, a1 lst8l: lb t0, 0(a1) addiu a0, 1 addiu a1, 1 bne a1, a3, lst8l sb t0, -1(a0) lst8e: jr ra # Bye, bye nop shift: subu a3, zero, a0 # Src and Dest unaligned andi a3, 0x3 # (unoptimized case...) beq a3, zero, shft1 subu a2, a3 # a2 = bytes left LWHI t0, 0(a1) # Take care of first odd part LWLO t0, 3(a1) addu a1, a3 SWHI t0, 0(a0) addu a0, a3 shft1: andi t0, a2, 0x3 subu a3, a2, t0 addu a3, a1 shfth: LWHI t1, 0(a1) # Limp through, word by word LWLO t1, 3(a1) addiu a0, 4 addiu a1, 4 bne a1, a3, shfth sw t1, -4(a0) b last8 # Handle anything which may be left move a2, t0 .set reorder