diff options
author | Denys Vlasenko <vda.linux@googlemail.com> | 2010-11-03 02:38:31 +0100 |
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committer | Denys Vlasenko <vda.linux@googlemail.com> | 2010-11-03 02:38:31 +0100 |
commit | 833d4e7f84f59099ee66eabfa3457ebb7d37eaa8 (patch) | |
tree | 3be84e1049707ce8077291065fe3689497c69b9c /archival/libunarchive/unxz/xz_dec_bcj.c | |
parent | 5e9934028aa030312a1a2e2e32d5ceade8672beb (diff) | |
download | busybox-833d4e7f84f59099ee66eabfa3457ebb7d37eaa8.tar.gz |
rename archival/libunarchive -> archival/libarchive; move bz/ into it
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'archival/libunarchive/unxz/xz_dec_bcj.c')
-rw-r--r-- | archival/libunarchive/unxz/xz_dec_bcj.c | 564 |
1 files changed, 0 insertions, 564 deletions
diff --git a/archival/libunarchive/unxz/xz_dec_bcj.c b/archival/libunarchive/unxz/xz_dec_bcj.c deleted file mode 100644 index 09162b51f..000000000 --- a/archival/libunarchive/unxz/xz_dec_bcj.c +++ /dev/null @@ -1,564 +0,0 @@ -/* - * Branch/Call/Jump (BCJ) filter decoders - * - * Authors: Lasse Collin <lasse.collin@tukaani.org> - * Igor Pavlov <http://7-zip.org/> - * - * This file has been put into the public domain. - * You can do whatever you want with this file. - */ - -#include "xz_private.h" - -/* - * The rest of the file is inside this ifdef. It makes things a little more - * convenient when building without support for any BCJ filters. - */ -#ifdef XZ_DEC_BCJ - -struct xz_dec_bcj { - /* Type of the BCJ filter being used */ - enum { - BCJ_X86 = 4, /* x86 or x86-64 */ - BCJ_POWERPC = 5, /* Big endian only */ - BCJ_IA64 = 6, /* Big or little endian */ - BCJ_ARM = 7, /* Little endian only */ - BCJ_ARMTHUMB = 8, /* Little endian only */ - BCJ_SPARC = 9 /* Big or little endian */ - } type; - - /* - * Return value of the next filter in the chain. We need to preserve - * this information across calls, because we must not call the next - * filter anymore once it has returned XZ_STREAM_END. - */ - enum xz_ret ret; - - /* True if we are operating in single-call mode. */ - bool single_call; - - /* - * Absolute position relative to the beginning of the uncompressed - * data (in a single .xz Block). We care only about the lowest 32 - * bits so this doesn't need to be uint64_t even with big files. - */ - uint32_t pos; - - /* x86 filter state */ - uint32_t x86_prev_mask; - - /* Temporary space to hold the variables from struct xz_buf */ - uint8_t *out; - size_t out_pos; - size_t out_size; - - struct { - /* Amount of already filtered data in the beginning of buf */ - size_t filtered; - - /* Total amount of data currently stored in buf */ - size_t size; - - /* - * Buffer to hold a mix of filtered and unfiltered data. This - * needs to be big enough to hold Alignment + 2 * Look-ahead: - * - * Type Alignment Look-ahead - * x86 1 4 - * PowerPC 4 0 - * IA-64 16 0 - * ARM 4 0 - * ARM-Thumb 2 2 - * SPARC 4 0 - */ - uint8_t buf[16]; - } temp; -}; - -#ifdef XZ_DEC_X86 -/* - * This is macro used to test the most significant byte of a memory address - * in an x86 instruction. - */ -#define bcj_x86_test_msbyte(b) ((b) == 0x00 || (b) == 0xFF) - -static noinline_for_stack size_t XZ_FUNC bcj_x86( - struct xz_dec_bcj *s, uint8_t *buf, size_t size) -{ - static const bool mask_to_allowed_status[8] - = { true, true, true, false, true, false, false, false }; - - static const uint8_t mask_to_bit_num[8] = { 0, 1, 2, 2, 3, 3, 3, 3 }; - - size_t i; - size_t prev_pos = (size_t)-1; - uint32_t prev_mask = s->x86_prev_mask; - uint32_t src; - uint32_t dest; - uint32_t j; - uint8_t b; - - if (size <= 4) - return 0; - - size -= 4; - for (i = 0; i < size; ++i) { - if ((buf[i] & 0xFE) != 0xE8) - continue; - - prev_pos = i - prev_pos; - if (prev_pos > 3) { - prev_mask = 0; - } else { - prev_mask = (prev_mask << (prev_pos - 1)) & 7; - if (prev_mask != 0) { - b = buf[i + 4 - mask_to_bit_num[prev_mask]]; - if (!mask_to_allowed_status[prev_mask] - || bcj_x86_test_msbyte(b)) { - prev_pos = i; - prev_mask = (prev_mask << 1) | 1; - continue; - } - } - } - - prev_pos = i; - - if (bcj_x86_test_msbyte(buf[i + 4])) { - src = get_unaligned_le32(buf + i + 1); - while (true) { - dest = src - (s->pos + (uint32_t)i + 5); - if (prev_mask == 0) - break; - - j = mask_to_bit_num[prev_mask] * 8; - b = (uint8_t)(dest >> (24 - j)); - if (!bcj_x86_test_msbyte(b)) - break; - - src = dest ^ (((uint32_t)1 << (32 - j)) - 1); - } - - dest &= 0x01FFFFFF; - dest |= (uint32_t)0 - (dest & 0x01000000); - put_unaligned_le32(dest, buf + i + 1); - i += 4; - } else { - prev_mask = (prev_mask << 1) | 1; - } - } - - prev_pos = i - prev_pos; - s->x86_prev_mask = prev_pos > 3 ? 0 : prev_mask << (prev_pos - 1); - return i; -} -#endif - -#ifdef XZ_DEC_POWERPC -static noinline_for_stack size_t XZ_FUNC bcj_powerpc( - struct xz_dec_bcj *s, uint8_t *buf, size_t size) -{ - size_t i; - uint32_t instr; - - for (i = 0; i + 4 <= size; i += 4) { - instr = get_unaligned_be32(buf + i); - if ((instr & 0xFC000003) == 0x48000001) { - instr &= 0x03FFFFFC; - instr -= s->pos + (uint32_t)i; - instr &= 0x03FFFFFC; - instr |= 0x48000001; - put_unaligned_be32(instr, buf + i); - } - } - - return i; -} -#endif - -#ifdef XZ_DEC_IA64 -static noinline_for_stack size_t XZ_FUNC bcj_ia64( - struct xz_dec_bcj *s, uint8_t *buf, size_t size) -{ - static const uint8_t branch_table[32] = { - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 4, 4, 6, 6, 0, 0, 7, 7, - 4, 4, 0, 0, 4, 4, 0, 0 - }; - - /* - * The local variables take a little bit stack space, but it's less - * than what LZMA2 decoder takes, so it doesn't make sense to reduce - * stack usage here without doing that for the LZMA2 decoder too. - */ - - /* Loop counters */ - size_t i; - size_t j; - - /* Instruction slot (0, 1, or 2) in the 128-bit instruction word */ - uint32_t slot; - - /* Bitwise offset of the instruction indicated by slot */ - uint32_t bit_pos; - - /* bit_pos split into byte and bit parts */ - uint32_t byte_pos; - uint32_t bit_res; - - /* Address part of an instruction */ - uint32_t addr; - - /* Mask used to detect which instructions to convert */ - uint32_t mask; - - /* 41-bit instruction stored somewhere in the lowest 48 bits */ - uint64_t instr; - - /* Instruction normalized with bit_res for easier manipulation */ - uint64_t norm; - - for (i = 0; i + 16 <= size; i += 16) { - mask = branch_table[buf[i] & 0x1F]; - for (slot = 0, bit_pos = 5; slot < 3; ++slot, bit_pos += 41) { - if (((mask >> slot) & 1) == 0) - continue; - - byte_pos = bit_pos >> 3; - bit_res = bit_pos & 7; - instr = 0; - for (j = 0; j < 6; ++j) - instr |= (uint64_t)(buf[i + j + byte_pos]) - << (8 * j); - - norm = instr >> bit_res; - - if (((norm >> 37) & 0x0F) == 0x05 - && ((norm >> 9) & 0x07) == 0) { - addr = (norm >> 13) & 0x0FFFFF; - addr |= ((uint32_t)(norm >> 36) & 1) << 20; - addr <<= 4; - addr -= s->pos + (uint32_t)i; - addr >>= 4; - - norm &= ~((uint64_t)0x8FFFFF << 13); - norm |= (uint64_t)(addr & 0x0FFFFF) << 13; - norm |= (uint64_t)(addr & 0x100000) - << (36 - 20); - - instr &= (1 << bit_res) - 1; - instr |= norm << bit_res; - - for (j = 0; j < 6; j++) - buf[i + j + byte_pos] - = (uint8_t)(instr >> (8 * j)); - } - } - } - - return i; -} -#endif - -#ifdef XZ_DEC_ARM -static noinline_for_stack size_t XZ_FUNC bcj_arm( - struct xz_dec_bcj *s, uint8_t *buf, size_t size) -{ - size_t i; - uint32_t addr; - - for (i = 0; i + 4 <= size; i += 4) { - if (buf[i + 3] == 0xEB) { - addr = (uint32_t)buf[i] | ((uint32_t)buf[i + 1] << 8) - | ((uint32_t)buf[i + 2] << 16); - addr <<= 2; - addr -= s->pos + (uint32_t)i + 8; - addr >>= 2; - buf[i] = (uint8_t)addr; - buf[i + 1] = (uint8_t)(addr >> 8); - buf[i + 2] = (uint8_t)(addr >> 16); - } - } - - return i; -} -#endif - -#ifdef XZ_DEC_ARMTHUMB -static noinline_for_stack size_t XZ_FUNC bcj_armthumb( - struct xz_dec_bcj *s, uint8_t *buf, size_t size) -{ - size_t i; - uint32_t addr; - - for (i = 0; i + 4 <= size; i += 2) { - if ((buf[i + 1] & 0xF8) == 0xF0 - && (buf[i + 3] & 0xF8) == 0xF8) { - addr = (((uint32_t)buf[i + 1] & 0x07) << 19) - | ((uint32_t)buf[i] << 11) - | (((uint32_t)buf[i + 3] & 0x07) << 8) - | (uint32_t)buf[i + 2]; - addr <<= 1; - addr -= s->pos + (uint32_t)i + 4; - addr >>= 1; - buf[i + 1] = (uint8_t)(0xF0 | ((addr >> 19) & 0x07)); - buf[i] = (uint8_t)(addr >> 11); - buf[i + 3] = (uint8_t)(0xF8 | ((addr >> 8) & 0x07)); - buf[i + 2] = (uint8_t)addr; - i += 2; - } - } - - return i; -} -#endif - -#ifdef XZ_DEC_SPARC -static noinline_for_stack size_t XZ_FUNC bcj_sparc( - struct xz_dec_bcj *s, uint8_t *buf, size_t size) -{ - size_t i; - uint32_t instr; - - for (i = 0; i + 4 <= size; i += 4) { - instr = get_unaligned_be32(buf + i); - if ((instr >> 22) == 0x100 || (instr >> 22) == 0x1FF) { - instr <<= 2; - instr -= s->pos + (uint32_t)i; - instr >>= 2; - instr = ((uint32_t)0x40000000 - (instr & 0x400000)) - | 0x40000000 | (instr & 0x3FFFFF); - put_unaligned_be32(instr, buf + i); - } - } - - return i; -} -#endif - -/* - * Apply the selected BCJ filter. Update *pos and s->pos to match the amount - * of data that got filtered. - * - * NOTE: This is implemented as a switch statement to avoid using function - * pointers, which could be problematic in the kernel boot code, which must - * avoid pointers to static data (at least on x86). - */ -static void XZ_FUNC bcj_apply(struct xz_dec_bcj *s, - uint8_t *buf, size_t *pos, size_t size) -{ - size_t filtered; - - buf += *pos; - size -= *pos; - - switch (s->type) { -#ifdef XZ_DEC_X86 - case BCJ_X86: - filtered = bcj_x86(s, buf, size); - break; -#endif -#ifdef XZ_DEC_POWERPC - case BCJ_POWERPC: - filtered = bcj_powerpc(s, buf, size); - break; -#endif -#ifdef XZ_DEC_IA64 - case BCJ_IA64: - filtered = bcj_ia64(s, buf, size); - break; -#endif -#ifdef XZ_DEC_ARM - case BCJ_ARM: - filtered = bcj_arm(s, buf, size); - break; -#endif -#ifdef XZ_DEC_ARMTHUMB - case BCJ_ARMTHUMB: - filtered = bcj_armthumb(s, buf, size); - break; -#endif -#ifdef XZ_DEC_SPARC - case BCJ_SPARC: - filtered = bcj_sparc(s, buf, size); - break; -#endif - default: - /* Never reached but silence compiler warnings. */ - filtered = 0; - break; - } - - *pos += filtered; - s->pos += filtered; -} - -/* - * Flush pending filtered data from temp to the output buffer. - * Move the remaining mixture of possibly filtered and unfiltered - * data to the beginning of temp. - */ -static void XZ_FUNC bcj_flush(struct xz_dec_bcj *s, struct xz_buf *b) -{ - size_t copy_size; - - copy_size = min_t(size_t, s->temp.filtered, b->out_size - b->out_pos); - memcpy(b->out + b->out_pos, s->temp.buf, copy_size); - b->out_pos += copy_size; - - s->temp.filtered -= copy_size; - s->temp.size -= copy_size; - memmove(s->temp.buf, s->temp.buf + copy_size, s->temp.size); -} - -/* - * The BCJ filter functions are primitive in sense that they process the - * data in chunks of 1-16 bytes. To hide this issue, this function does - * some buffering. - */ -XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_bcj_run(struct xz_dec_bcj *s, - struct xz_dec_lzma2 *lzma2, struct xz_buf *b) -{ - size_t out_start; - - /* - * Flush pending already filtered data to the output buffer. Return - * immediatelly if we couldn't flush everything, or if the next - * filter in the chain had already returned XZ_STREAM_END. - */ - if (s->temp.filtered > 0) { - bcj_flush(s, b); - if (s->temp.filtered > 0) - return XZ_OK; - - if (s->ret == XZ_STREAM_END) - return XZ_STREAM_END; - } - - /* - * If we have more output space than what is currently pending in - * temp, copy the unfiltered data from temp to the output buffer - * and try to fill the output buffer by decoding more data from the - * next filter in the chain. Apply the BCJ filter on the new data - * in the output buffer. If everything cannot be filtered, copy it - * to temp and rewind the output buffer position accordingly. - */ - if (s->temp.size < b->out_size - b->out_pos) { - out_start = b->out_pos; - memcpy(b->out + b->out_pos, s->temp.buf, s->temp.size); - b->out_pos += s->temp.size; - - s->ret = xz_dec_lzma2_run(lzma2, b); - if (s->ret != XZ_STREAM_END - && (s->ret != XZ_OK || s->single_call)) - return s->ret; - - bcj_apply(s, b->out, &out_start, b->out_pos); - - /* - * As an exception, if the next filter returned XZ_STREAM_END, - * we can do that too, since the last few bytes that remain - * unfiltered are meant to remain unfiltered. - */ - if (s->ret == XZ_STREAM_END) - return XZ_STREAM_END; - - s->temp.size = b->out_pos - out_start; - b->out_pos -= s->temp.size; - memcpy(s->temp.buf, b->out + b->out_pos, s->temp.size); - } - - /* - * If we have unfiltered data in temp, try to fill by decoding more - * data from the next filter. Apply the BCJ filter on temp. Then we - * hopefully can fill the actual output buffer by copying filtered - * data from temp. A mix of filtered and unfiltered data may be left - * in temp; it will be taken care on the next call to this function. - */ - if (s->temp.size > 0) { - /* Make b->out{,_pos,_size} temporarily point to s->temp. */ - s->out = b->out; - s->out_pos = b->out_pos; - s->out_size = b->out_size; - b->out = s->temp.buf; - b->out_pos = s->temp.size; - b->out_size = sizeof(s->temp.buf); - - s->ret = xz_dec_lzma2_run(lzma2, b); - - s->temp.size = b->out_pos; - b->out = s->out; - b->out_pos = s->out_pos; - b->out_size = s->out_size; - - if (s->ret != XZ_OK && s->ret != XZ_STREAM_END) - return s->ret; - - bcj_apply(s, s->temp.buf, &s->temp.filtered, s->temp.size); - - /* - * If the next filter returned XZ_STREAM_END, we mark that - * everything is filtered, since the last unfiltered bytes - * of the stream are meant to be left as is. - */ - if (s->ret == XZ_STREAM_END) - s->temp.filtered = s->temp.size; - - bcj_flush(s, b); - if (s->temp.filtered > 0) - return XZ_OK; - } - - return s->ret; -} - -XZ_EXTERN struct xz_dec_bcj * XZ_FUNC xz_dec_bcj_create(bool single_call) -{ - struct xz_dec_bcj *s = kmalloc(sizeof(*s), GFP_KERNEL); - if (s != NULL) - s->single_call = single_call; - - return s; -} - -XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_bcj_reset( - struct xz_dec_bcj *s, uint8_t id) -{ - switch (id) { -#ifdef XZ_DEC_X86 - case BCJ_X86: -#endif -#ifdef XZ_DEC_POWERPC - case BCJ_POWERPC: -#endif -#ifdef XZ_DEC_IA64 - case BCJ_IA64: -#endif -#ifdef XZ_DEC_ARM - case BCJ_ARM: -#endif -#ifdef XZ_DEC_ARMTHUMB - case BCJ_ARMTHUMB: -#endif -#ifdef XZ_DEC_SPARC - case BCJ_SPARC: -#endif - break; - - default: - /* Unsupported Filter ID */ - return XZ_OPTIONS_ERROR; - } - - s->type = id; - s->ret = XZ_OK; - s->pos = 0; - s->x86_prev_mask = 0; - s->temp.filtered = 0; - s->temp.size = 0; - - return XZ_OK; -} - -#endif |