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-rw-r--r--lib/ext2fs/crc32c_defs.h59
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/ext2fs/crc32c_defs.h b/lib/ext2fs/crc32c_defs.h
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+++ b/lib/ext2fs/crc32c_defs.h
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+/*
+ * There are multiple 16-bit CRC polynomials in common use, but this is
+ * *the* standard CRC-32 polynomial, first popularized by Ethernet.
+ * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0
+ */
+#define CRCPOLY_LE 0xedb88320
+#define CRCPOLY_BE 0x04c11db7
+
+/*
+ * This is the CRC32c polynomial, as outlined by Castagnoli.
+ * x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+
+ * x^8+x^6+x^0
+ */
+#define CRC32C_POLY_LE 0x82F63B78
+#define CRC32C_POLY_BE 0x1EDC6F41
+
+/* How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64. */
+/* For less performance-sensitive, use 4 */
+#ifndef CRC_LE_BITS
+# define CRC_LE_BITS 64
+#endif
+#ifndef CRC_BE_BITS
+# define CRC_BE_BITS 64
+#endif
+
+/*
+ * Little-endian CRC computation. Used with serial bit streams sent
+ * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC.
+ */
+#if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
+ CRC_LE_BITS & CRC_LE_BITS-1
+# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}"
+#endif
+
+/*
+ * Big-endian CRC computation. Used with serial bit streams sent
+ * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC.
+ */
+#if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
+ CRC_BE_BITS & CRC_BE_BITS-1
+# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}"
+#endif
+
+
+#define ___constant_swab32(x) \
+ ((uint32_t)( \
+ (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
+ (((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
+ (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >> 8) | \
+ (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
+
+
+#if (__GNUC__ >= 3)
+#define likely(x) __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+#else
+#define likely(x) (x)
+#define unlikely(x) (x)
+#endif