1 files changed, 313 insertions, 0 deletions
diff --git a/src/liblzma/check/crc32_x86.S b/src/liblzma/check/crc32_x86.S
new file mode 100644
index 0000000..4f395df
--- /dev/null
+++ b/src/liblzma/check/crc32_x86.S
@@ -0,0 +1,313 @@
+/*
+ * 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);
+ */
+
+/* When Intel CET is enabled, include <cet.h> in assembly code to mark
+   Intel CET support.  */
+#ifdef __CET__
+# include <cet.h>
+#else
+# define _CET_ENDBR
+#endif
+
+/*
+ * 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:
+	_CET_ENDBR
+	/*
+	 * 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 iteration 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 __FreeBSD__ and __linux__ here, but I don't know a way to detect when
+ * we are using GNU assembler.
+ */
+#if defined(__ELF__) && (defined(__FreeBSD__) || defined(__linux__))
+	.section	.note.GNU-stack,"",@progbits
+#endif