lkml.org 
[lkml]   [2003]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: Algoritmic Complexity Attacks and 2.4.20 the dcache code
From
   From: Alex Riesen <alexander.riesen@synopsys.COM>
Date: Fri, 30 May 2003 10:59:01 +0200

static
int hash_3(int hi, int c)
{
return (hi + (c << 4) + (c >> 4)) * 11;
}

gcc-3.2.1 -O2 -march=pentium
...
It is not guaranteed to be this way on all architectures, of course.
But still - no multiplications.

Indeed, I'd missed this. GCC will emit the constant multiply
expansion unless the multiply cost is set VERY low.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:35    [W:0.055 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site