cpuid? It seems to me that the *only* thing that should determine how the program gets compiled is the compiler flags, since the target platform might have either less or more capability than the build machine. I've experienced both cases, firsthand. GCC will define the following preprocessor macros, depending on which code generation flags you specify: __MMX__ __SSE__ __SSE2__ __SSE3__ __SSSE3__ __SSE4A__ __SSE4_1__ __SSE4_2__ __AES__ __PCLMUL__ __AVX__ Matt ________________________________ From: boost-bounces@lists.boost.org on behalf of Mathias Gaunard Sent: Wed 3/23/2011 7:44 PM To: boost@lists.boost.org Subject: Re: [boost] [GSoC] SIMD proposal On 23/03/2011 21:45, Mathieu - wrote:
One of the main concern I have is that nt2 relies heavily on cmake to detect various things like SSE instruction set support etc.
The library must know what instruction sets are available on the target machine. This is done using a configuration header file that contains macros that exist if the instruction sets in question are available. That configuration header can be either written manually or be generated by the build system. On x86, we use a program that calls the 'cpuid' instruction (using inline assembler) which directly gives the processor capabilities. Then we check the compiler allows their usage (MSVC Express Edition does not allow SSE3+). ...