diff options
author | David Woodhouse <dwmw2@infradead.org> | 2007-01-18 10:34:51 +1100 |
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committer | David Woodhouse <dwmw2@infradead.org> | 2007-01-18 10:34:51 +1100 |
commit | 9cdf083f981b8d37b3212400a359368661385099 (patch) | |
tree | aa15a6a08ad87e650dea40fb59b3180bef0d345b /lib/crc32.c | |
parent | e499e01d234a31d59679b7b1e1cf628d917ba49a (diff) | |
parent | a8b3485287731978899ced11f24628c927890e78 (diff) |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'lib/crc32.c')
-rw-r--r-- | lib/crc32.c | 28 |
1 files changed, 5 insertions, 23 deletions
diff --git a/lib/crc32.c b/lib/crc32.c index 285fd9bc61b..bfc33314c72 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -235,23 +235,8 @@ u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len) } #endif -/** - * bitreverse - reverse the order of bits in a u32 value - * @x: value to be bit-reversed - */ -u32 bitreverse(u32 x) -{ - x = (x >> 16) | (x << 16); - x = (x >> 8 & 0x00ff00ff) | (x << 8 & 0xff00ff00); - x = (x >> 4 & 0x0f0f0f0f) | (x << 4 & 0xf0f0f0f0); - x = (x >> 2 & 0x33333333) | (x << 2 & 0xcccccccc); - x = (x >> 1 & 0x55555555) | (x << 1 & 0xaaaaaaaa); - return x; -} - EXPORT_SYMBOL(crc32_le); EXPORT_SYMBOL(crc32_be); -EXPORT_SYMBOL(bitreverse); /* * A brief CRC tutorial. @@ -400,10 +385,7 @@ buf_dump(char const *prefix, unsigned char const *buf, size_t len) static void bytereverse(unsigned char *buf, size_t len) { while (len--) { - unsigned char x = *buf; - x = (x >> 4) | (x << 4); - x = (x >> 2 & 0x33) | (x << 2 & 0xcc); - x = (x >> 1 & 0x55) | (x << 1 & 0xaa); + unsigned char x = bitrev8(*buf); *buf++ = x; } } @@ -460,11 +442,11 @@ static u32 test_step(u32 init, unsigned char *buf, size_t len) /* Now swap it around for the other test */ bytereverse(buf, len + 4); - init = bitreverse(init); - crc2 = bitreverse(crc1); - if (crc1 != bitreverse(crc2)) + init = bitrev32(init); + crc2 = bitrev32(crc1); + if (crc1 != bitrev32(crc2)) printf("\nBit reversal fail: 0x%08x -> 0x%08x -> 0x%08x\n", - crc1, crc2, bitreverse(crc2)); + crc1, crc2, bitrev32(crc2)); crc1 = crc32_le(init, buf, len); if (crc1 != crc2) printf("\nCRC endianness fail: 0x%08x != 0x%08x\n", crc1, |