semantic: 0.983 graphic: 0.873 device: 0.790 socket: 0.764 vnc: 0.756 boot: 0.678 network: 0.672 performance: 0.656 files: 0.633 permissions: 0.619 other: 0.609 debug: 0.525 PID: 0.488 KVM: 0.412 x86 BLSI and BLSR semantic bug Description of problem The result of instruction BLSI and BLSR is different from the CPU. The value of CF is different. Steps to reproduce Compile this code void main() { asm("blsi rax, rbx"); } Execute and compare the result with the CPU. The value of CF is exactly the opposite. This problem happens with BLSR, too. Additional information This bug is discovered by research conducted by KAIST SoftSec.