I am using Linux and 8-core x86 platform. First how do I find the cache line size.
$ getconf LEVEL1_DCACHE_LINESIZE
64
Pass the value as a macro definition to the compiler.
$ gcc -DLEVEL1_DCACHE_LINESIZE=`getconf LEVEL1_DCACHE_LINESIZE` ...
At run-time sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
can be used to get L1 cache size.