mirror of
https://git.tukaani.org/xz.git
synced 2025-11-04 15:32:55 +00:00
c15115f7ed
Compilers cannot optimize the addition "i + 4" away since theoretically it could overflow.
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
// SPDX-License-Identifier: 0BSD
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
/// \file powerpc.c
|
|
/// \brief Filter for PowerPC (big endian) binaries
|
|
///
|
|
// Authors: Igor Pavlov
|
|
// Lasse Collin
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include "simple_private.h"
|
|
|
|
|
|
static size_t
|
|
powerpc_code(void *simple lzma_attribute((__unused__)),
|
|
uint32_t now_pos, bool is_encoder,
|
|
uint8_t *buffer, size_t size)
|
|
{
|
|
size &= ~(size_t)3;
|
|
|
|
size_t i;
|
|
for (i = 0; i < size; i += 4) {
|
|
// PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link)
|
|
if ((buffer[i] >> 2) == 0x12
|
|
&& ((buffer[i + 3] & 3) == 1)) {
|
|
|
|
const uint32_t src
|
|
= (((uint32_t)(buffer[i + 0]) & 3) << 24)
|
|
| ((uint32_t)(buffer[i + 1]) << 16)
|
|
| ((uint32_t)(buffer[i + 2]) << 8)
|
|
| ((uint32_t)(buffer[i + 3]) & ~UINT32_C(3));
|
|
|
|
uint32_t dest;
|
|
if (is_encoder)
|
|
dest = now_pos + (uint32_t)(i) + src;
|
|
else
|
|
dest = src - (now_pos + (uint32_t)(i));
|
|
|
|
buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03);
|
|
buffer[i + 1] = (dest >> 16);
|
|
buffer[i + 2] = (dest >> 8);
|
|
buffer[i + 3] &= 0x03;
|
|
buffer[i + 3] |= dest;
|
|
}
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
|
|
static lzma_ret
|
|
powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
|
|
const lzma_filter_info *filters, bool is_encoder)
|
|
{
|
|
return lzma_simple_coder_init(next, allocator, filters,
|
|
&powerpc_code, 0, 4, 4, is_encoder);
|
|
}
|
|
|
|
|
|
#ifdef HAVE_ENCODER_POWERPC
|
|
extern lzma_ret
|
|
lzma_simple_powerpc_encoder_init(lzma_next_coder *next,
|
|
const lzma_allocator *allocator,
|
|
const lzma_filter_info *filters)
|
|
{
|
|
return powerpc_coder_init(next, allocator, filters, true);
|
|
}
|
|
#endif
|
|
|
|
|
|
#ifdef HAVE_DECODER_POWERPC
|
|
extern lzma_ret
|
|
lzma_simple_powerpc_decoder_init(lzma_next_coder *next,
|
|
const lzma_allocator *allocator,
|
|
const lzma_filter_info *filters)
|
|
{
|
|
return powerpc_coder_init(next, allocator, filters, false);
|
|
}
|
|
#endif
|