memory.h

 
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#ifndef PSP_MEMORY_H
#define PSP_MEMORY_H
 
#define MIN_AMOUNT_FOR_COMPLEX_COPY  8
#define MIN_AMOUNT_FOR_MISALIGNED_COPY 8
 
//#define __PSP_DEBUG_PRINT__
 
//#include "backends/platform/psp/trace.h"
 
// These instructions don't generate automatically but are faster then copying byte by byte
inline void lwl_copy(byte *dst, const byte *src) {
    uint32 data;
    asm volatile ("lwr %0,0(%1)\n\t"
         "lwl %0,3(%1)\n\t"
         : "=&r" (data) : "r" (src), "m" (*src));
 
    asm volatile ("swr %1,0(%2)\n\t"
         "swl %1,3(%2)\n\t"
         : "=m" (*dst) : "r" (data), "r" (dst));
}
 
class PspMemory {
private:
    static void testCopy(const byte *debugDst, const byte *debugSrc, uint32 debugBytes);
    static void copy(byte *dst, const byte *src, uint32 bytes);
    static void copy32Aligned(uint32 *dst32, const uint32 *src32, uint32 bytes);
    static void copy32Misaligned(uint32 *dst32, const byte *src, uint32 bytes, uint32 alignSrc);
 
    static inline void copy8(byte *dst, const byte *src, int32 bytes) {
        //PSP_DEBUG_PRINT("copy8 called with dst[%p], src[%p], bytes[%d]\n", dst, src, bytes);
        uint32 words = bytes >> 2;
        for (; words; words--) {
            lwl_copy(dst, src);
            dst += 4;
            src += 4;
        }
 
        uint32 bytesLeft = bytes & 0x3;
        for (; bytesLeft; bytesLeft--) {
            *dst++ = *src++;
        }
    }
 
public:
    // This is the interface to the outside world
    static void *fastCopy(void *dstv, const void *srcv, int32 bytes) {
        byte *dst = (byte *)dstv;
        const byte *src = (const byte *)srcv;
 
        if (bytes < MIN_AMOUNT_FOR_COMPLEX_COPY) {
            copy8(dst, src, bytes);
        } else {    // go to more powerful copy
            copy(dst, src, bytes);
        }
 
        return dstv;
    }
};
 
inline void *psp_memcpy(void *dst, const void *src, int32 bytes) {
    return PspMemory::fastCopy(dst, src, bytes);
}
 
#endif /* PSP_MEMORY_H */