4 ms·
Indeed works. A simple trace reveals that the function is called mkl_serv_intel_cpu_true(). Make a file with the following content: int mkl_serv_intel_cpu
by danieldk 6y ago
Indeed works. A simple trace reveals that the function is called mkl_serv_intel_cpu_true().
Make a file with the following content:
int mkl_serv_intel_cpu_true() {
return 1;
}
Compile
gcc -shared -o libfake.so fake.c
Run
LD_PRELOAD=libfake.so yourprogram
And it uses the optimized AVX codepaths.
Disclaimer: may not be legal in your country. I take no responsibility.
- ashleyn 6y agoWow. I wasn't quite expecting something as simple as "if CPU is not intel, make everything worse."
- colejohnson66 6y agoI’m sure their justification is that (1) they have no obligation to help AMD, and (2) how could you guarantee AMD implements CPUID the same as Intel (as in: what if AMD implements a feature bit differently?) Of course, the second one makes no sense as x86 programs run just as fine on AMD as Intel with the same feature set (albeit at different speeds)
- danieldk 6y agoBy the way, if you want make this permanent in a binary, there is no need to set LD_PRELOAD all the time. You could just add a DT_NEEDED entry to the dynamic section. E.g. something like: patchelf --add-needed libfakeintel.so yourbinary