LLVM Lands Performance-Hitting Mitigation For Intel LVI Vulnerability

When using the SMHasher test suite to test various hashing functions, the throughput was only minimally impacted but the CPU cycles needed per hash did shoot up significantly from having the LVI mitigation when compiling the software with LLVM 11 Clang. The number of cycles per hash shot up by 30%+ with the LLVM LVI mitigation.

John The Ripper's MD5 hashing benchmark saw a minor hit as well to the performance from this LVI mitigation.

When turning to the LAMMPS molecular dynamics simulator for some scientific application coverage, the LVI mitigation in LLVM had a minor impact on the performance.

Video encoding/decoding were seeing performance hits as well from LLVM's LVI mitigation though the impact varied depending upon each particular code-base.