Fixed x2APIC discovery for 256-processor architectures.
Fixed x2APIC discovery for 256-processor architectures.

Mask for value read from ebx register returned by CPUID expanded to 0xFFFF.

Differential Revision: https://reviews.llvm.org/D23203

git-svn-id: f99161ee8ccfe2101cbe1bdda2220bce2ed25485@277825 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/openmp,llvm-mirror/openmp,llvm-mirror/openmp,llvm-mirror/openmp,llvm-mirror/openmp