| Index: xz/src/liblzma/check/crc32_x86.S
|
| ===================================================================
|
| --- xz/src/liblzma/check/crc32_x86.S (revision 0)
|
| +++ xz/src/liblzma/check/crc32_x86.S (revision 0)
|
| @@ -0,0 +1,304 @@
|
| +/*
|
| + * Speed-optimized CRC32 using slicing-by-eight algorithm
|
| + *
|
| + * This uses only i386 instructions, but it is optimized for i686 and later
|
| + * (including e.g. Pentium II/III/IV, Athlon XP, and Core 2). For i586
|
| + * (e.g. Pentium), slicing-by-four would be better, and even the C version
|
| + * of slicing-by-eight built with gcc -march=i586 tends to be a little bit
|
| + * better than this. Very few probably run this code on i586 or older x86
|
| + * so this shouldn't be a problem in practice.
|
| + *
|
| + * Authors: Igor Pavlov (original version)
|
| + * Lasse Collin (AT&T syntax, PIC support, better portability)
|
| + *
|
| + * This file has been put into the public domain.
|
| + * You can do whatever you want with this file.
|
| + *
|
| + * This code needs lzma_crc32_table, which can be created using the
|
| + * following C code:
|
| +
|
| +uint32_t lzma_crc32_table[8][256];
|
| +
|
| +void
|
| +init_table(void)
|
| +{
|
| + // IEEE-802.3
|
| + static const uint32_t poly32 = UINT32_C(0xEDB88320);
|
| +
|
| + // Castagnoli
|
| + // static const uint32_t poly32 = UINT32_C(0x82F63B78);
|
| +
|
| + // Koopman
|
| + // static const uint32_t poly32 = UINT32_C(0xEB31D82E);
|
| +
|
| + for (size_t s = 0; s < 8; ++s) {
|
| + for (size_t b = 0; b < 256; ++b) {
|
| + uint32_t r = s == 0 ? b : lzma_crc32_table[s - 1][b];
|
| +
|
| + for (size_t i = 0; i < 8; ++i) {
|
| + if (r & 1)
|
| + r = (r >> 1) ^ poly32;
|
| + else
|
| + r >>= 1;
|
| + }
|
| +
|
| + lzma_crc32_table[s][b] = r;
|
| + }
|
| + }
|
| +}
|
| +
|
| + * The prototype of the CRC32 function:
|
| + * extern uint32_t lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc);
|
| + */
|
| +
|
| +/*
|
| + * On some systems, the functions need to be prefixed. The prefix is
|
| + * usually an underscore.
|
| + */
|
| +#ifndef __USER_LABEL_PREFIX__
|
| +# define __USER_LABEL_PREFIX__
|
| +#endif
|
| +#define MAKE_SYM_CAT(prefix, sym) prefix ## sym
|
| +#define MAKE_SYM(prefix, sym) MAKE_SYM_CAT(prefix, sym)
|
| +#define LZMA_CRC32 MAKE_SYM(__USER_LABEL_PREFIX__, lzma_crc32)
|
| +#define LZMA_CRC32_TABLE MAKE_SYM(__USER_LABEL_PREFIX__, lzma_crc32_table)
|
| +
|
| +/*
|
| + * Solaris assembler doesn't have .p2align, and Darwin uses .align
|
| + * differently than GNU/Linux and Solaris.
|
| + */
|
| +#if defined(__APPLE__) || defined(__MSDOS__)
|
| +# define ALIGN(pow2, abs) .align pow2
|
| +#else
|
| +# define ALIGN(pow2, abs) .align abs
|
| +#endif
|
| +
|
| + .text
|
| + .globl LZMA_CRC32
|
| +
|
| +#if !defined(__APPLE__) && !defined(_WIN32) && !defined(__CYGWIN__) \
|
| + && !defined(__MSDOS__)
|
| + .type LZMA_CRC32, @function
|
| +#endif
|
| +
|
| + ALIGN(4, 16)
|
| +LZMA_CRC32:
|
| + /*
|
| + * Register usage:
|
| + * %eax crc
|
| + * %esi buf
|
| + * %edi size or buf + size
|
| + * %ebx lzma_crc32_table
|
| + * %ebp Table index
|
| + * %ecx Temporary
|
| + * %edx Temporary
|
| + */
|
| + pushl %ebx
|
| + pushl %esi
|
| + pushl %edi
|
| + pushl %ebp
|
| + movl 0x14(%esp), %esi /* buf */
|
| + movl 0x18(%esp), %edi /* size */
|
| + movl 0x1C(%esp), %eax /* crc */
|
| +
|
| + /*
|
| + * Store the address of lzma_crc32_table to %ebx. This is needed to
|
| + * get position-independent code (PIC).
|
| + *
|
| + * The PIC macro is defined by libtool, while __PIC__ is defined
|
| + * by GCC but only on some systems. Testing for both makes it simpler
|
| + * to test this code without libtool, and keeps the code working also
|
| + * when built with libtool but using something else than GCC.
|
| + *
|
| + * I understood that libtool may define PIC on Windows even though
|
| + * the code in Windows DLLs is not PIC in sense that it is in ELF
|
| + * binaries, so we need a separate check to always use the non-PIC
|
| + * code on Windows.
|
| + */
|
| +#if (!defined(PIC) && !defined(__PIC__)) \
|
| + || (defined(_WIN32) || defined(__CYGWIN__))
|
| + /* Not PIC */
|
| + movl $ LZMA_CRC32_TABLE, %ebx
|
| +#elif defined(__APPLE__)
|
| + /* Mach-O */
|
| + call .L_get_pc
|
| +.L_pic:
|
| + leal .L_lzma_crc32_table$non_lazy_ptr-.L_pic(%ebx), %ebx
|
| + movl (%ebx), %ebx
|
| +#else
|
| + /* ELF */
|
| + call .L_get_pc
|
| + addl $_GLOBAL_OFFSET_TABLE_, %ebx
|
| + movl LZMA_CRC32_TABLE@GOT(%ebx), %ebx
|
| +#endif
|
| +
|
| + /* Complement the initial value. */
|
| + notl %eax
|
| +
|
| + ALIGN(4, 16)
|
| +.L_align:
|
| + /*
|
| + * Check if there is enough input to use slicing-by-eight.
|
| + * We need 16 bytes, because the loop pre-reads eight bytes.
|
| + */
|
| + cmpl $16, %edi
|
| + jb .L_rest
|
| +
|
| + /* Check if we have reached alignment of eight bytes. */
|
| + testl $7, %esi
|
| + jz .L_slice
|
| +
|
| + /* Calculate CRC of the next input byte. */
|
| + movzbl (%esi), %ebp
|
| + incl %esi
|
| + movzbl %al, %ecx
|
| + xorl %ecx, %ebp
|
| + shrl $8, %eax
|
| + xorl (%ebx, %ebp, 4), %eax
|
| + decl %edi
|
| + jmp .L_align
|
| +
|
| + ALIGN(2, 4)
|
| +.L_slice:
|
| + /*
|
| + * If we get here, there's at least 16 bytes of aligned input
|
| + * available. Make %edi multiple of eight bytes. Store the possible
|
| + * remainder over the "size" variable in the argument stack.
|
| + */
|
| + movl %edi, 0x18(%esp)
|
| + andl $-8, %edi
|
| + subl %edi, 0x18(%esp)
|
| +
|
| + /*
|
| + * Let %edi be buf + size - 8 while running the main loop. This way
|
| + * we can compare for equality to determine when exit the loop.
|
| + */
|
| + addl %esi, %edi
|
| + subl $8, %edi
|
| +
|
| + /* Read in the first eight aligned bytes. */
|
| + xorl (%esi), %eax
|
| + movl 4(%esi), %ecx
|
| + movzbl %cl, %ebp
|
| +
|
| +.L_loop:
|
| + movl 0x0C00(%ebx, %ebp, 4), %edx
|
| + movzbl %ch, %ebp
|
| + xorl 0x0800(%ebx, %ebp, 4), %edx
|
| + shrl $16, %ecx
|
| + xorl 8(%esi), %edx
|
| + movzbl %cl, %ebp
|
| + xorl 0x0400(%ebx, %ebp, 4), %edx
|
| + movzbl %ch, %ebp
|
| + xorl (%ebx, %ebp, 4), %edx
|
| + movzbl %al, %ebp
|
| +
|
| + /*
|
| + * Read the next four bytes, for which the CRC is calculated
|
| + * on the next interation of the loop.
|
| + */
|
| + movl 12(%esi), %ecx
|
| +
|
| + xorl 0x1C00(%ebx, %ebp, 4), %edx
|
| + movzbl %ah, %ebp
|
| + shrl $16, %eax
|
| + xorl 0x1800(%ebx, %ebp, 4), %edx
|
| + movzbl %ah, %ebp
|
| + movzbl %al, %eax
|
| + movl 0x1400(%ebx, %eax, 4), %eax
|
| + addl $8, %esi
|
| + xorl %edx, %eax
|
| + xorl 0x1000(%ebx, %ebp, 4), %eax
|
| +
|
| + /* Check for end of aligned input. */
|
| + cmpl %edi, %esi
|
| + movzbl %cl, %ebp
|
| + jne .L_loop
|
| +
|
| + /*
|
| + * Process the remaining eight bytes, which we have already
|
| + * copied to %ecx and %edx.
|
| + */
|
| + movl 0x0C00(%ebx, %ebp, 4), %edx
|
| + movzbl %ch, %ebp
|
| + xorl 0x0800(%ebx, %ebp, 4), %edx
|
| + shrl $16, %ecx
|
| + movzbl %cl, %ebp
|
| + xorl 0x0400(%ebx, %ebp, 4), %edx
|
| + movzbl %ch, %ebp
|
| + xorl (%ebx, %ebp, 4), %edx
|
| + movzbl %al, %ebp
|
| +
|
| + xorl 0x1C00(%ebx, %ebp, 4), %edx
|
| + movzbl %ah, %ebp
|
| + shrl $16, %eax
|
| + xorl 0x1800(%ebx, %ebp, 4), %edx
|
| + movzbl %ah, %ebp
|
| + movzbl %al, %eax
|
| + movl 0x1400(%ebx, %eax, 4), %eax
|
| + addl $8, %esi
|
| + xorl %edx, %eax
|
| + xorl 0x1000(%ebx, %ebp, 4), %eax
|
| +
|
| + /* Copy the number of remaining bytes to %edi. */
|
| + movl 0x18(%esp), %edi
|
| +
|
| +.L_rest:
|
| + /* Check for end of input. */
|
| + testl %edi, %edi
|
| + jz .L_return
|
| +
|
| + /* Calculate CRC of the next input byte. */
|
| + movzbl (%esi), %ebp
|
| + incl %esi
|
| + movzbl %al, %ecx
|
| + xorl %ecx, %ebp
|
| + shrl $8, %eax
|
| + xorl (%ebx, %ebp, 4), %eax
|
| + decl %edi
|
| + jmp .L_rest
|
| +
|
| +.L_return:
|
| + /* Complement the final value. */
|
| + notl %eax
|
| +
|
| + popl %ebp
|
| + popl %edi
|
| + popl %esi
|
| + popl %ebx
|
| + ret
|
| +
|
| +#if defined(PIC) || defined(__PIC__)
|
| + ALIGN(4, 16)
|
| +.L_get_pc:
|
| + movl (%esp), %ebx
|
| + ret
|
| +#endif
|
| +
|
| +#if defined(__APPLE__) && (defined(PIC) || defined(__PIC__))
|
| + /* Mach-O PIC */
|
| + .section __IMPORT,__pointers,non_lazy_symbol_pointers
|
| +.L_lzma_crc32_table$non_lazy_ptr:
|
| + .indirect_symbol LZMA_CRC32_TABLE
|
| + .long 0
|
| +
|
| +#elif defined(_WIN32) || defined(__CYGWIN__)
|
| +# ifdef DLL_EXPORT
|
| + /* This is equivalent of __declspec(dllexport). */
|
| + .section .drectve
|
| + .ascii " -export:lzma_crc32"
|
| +# endif
|
| +
|
| +#elif !defined(__MSDOS__)
|
| + /* ELF */
|
| + .size LZMA_CRC32, .-LZMA_CRC32
|
| +#endif
|
| +
|
| +/*
|
| + * This is needed to support non-executable stack. It's ugly to
|
| + * use __linux__ here, but I don't know a way to detect when
|
| + * we are using GNU assembler.
|
| + */
|
| +#if defined(__ELF__) && defined(__linux__)
|
| + .section .note.GNU-stack,"",@progbits
|
| +#endif
|
|
|
| Property changes on: xz/src/liblzma/check/crc32_x86.S
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|