x86: 0.997 semantic: 0.987 architecture: 0.935 assembly: 0.879 device: 0.743 graphic: 0.735 vnc: 0.612 socket: 0.607 mistranslation: 0.603 boot: 0.585 register: 0.568 arm: 0.512 risc-v: 0.501 debug: 0.428 permissions: 0.370 network: 0.366 files: 0.340 PID: 0.289 other: 0.269 performance: 0.268 TCG: 0.254 kernel virtual machine: 0.130 x86 BLSMSK semantic bug Description of problem The result of instruction BLSMSK is different with from the CPU. The value of CF is different. Steps to reproduce Compile this code void main() { asm("mov rax, 0x65b2e276ad27c67"); asm("mov rbx, 0x62f34955226b2b5d"); asm("blsmsk eax, ebx"); } Execute and compare the result with the CPU. CPU CF = 0 QEMU CF = 1 Additional information This bug is discovered by research conducted by KAIST SoftSec.