From 90258fdadace50db3ef72a46aa84e9004c7cb61a Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Tue, 16 Apr 2013 00:06:18 +0200 Subject: fix binary logarithm MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- c/sha3.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'c') diff --git a/c/sha3.c b/c/sha3.c index d8981ed..72f3e83 100644 --- a/c/sha3.c +++ b/c/sha3.c @@ -241,10 +241,18 @@ inline void revarraycopy(byte* src, long soff, byte* dest, long doff, long lengt /** * Binary logarithm * - * @param X:long The value of which to calculate the binary logarithm - * @return :long The binary logarithm + * @param x The value of which to calculate the binary logarithm + * @return The binary logarithm */ -#define lb(X) ((((X & 0xFF00) == 0 ? 0 : 8) + ((X & 0xF0F0) == 0 ? 0 : 4)) + (((X & 0xCCCC) == 0 ? 0 : 2) + ((X & 0xAAAA) == 0 ? 0 : 1))) +static long lb(long x) +{ + long rc = 0; + if ((x & 0xFF00) != 0) { rc += 8; x >>= 8; } + if ((x & 0x00F0) != 0) { rc += 4; x >>= 4; } + if ((x & 0x000C) != 0) { rc += 2; x >>= 2; } + if ((x & 0x0002) != 0) rc += 1; + return rc; +} /** -- cgit v1.2.3-70-g09d2