x86: 0.997 semantic: 0.987 architecture: 0.935 assembly: 0.879 i386: 0.871 device: 0.743 graphic: 0.735 ppc: 0.729 operating system: 0.627 vnc: 0.612 socket: 0.607 mistranslation: 0.603 boot: 0.585 register: 0.568 alpha: 0.543 kernel: 0.521 arm: 0.512 risc-v: 0.501 debug: 0.428 permissions: 0.370 network: 0.366 files: 0.340 PID: 0.289 performance: 0.268 TCG: 0.254 VMM: 0.231 virtual: 0.185 KVM: 0.163 peripherals: 0.134 hypervisor: 0.067 user-level: 0.028 -------------------- x86: 1.000 semantic: 0.987 assembly: 0.982 i386: 0.968 debug: 0.389 register: 0.292 operating system: 0.057 kernel: 0.047 files: 0.027 performance: 0.021 virtual: 0.019 TCG: 0.016 peripherals: 0.011 user-level: 0.011 device: 0.009 PID: 0.008 architecture: 0.008 hypervisor: 0.006 VMM: 0.005 KVM: 0.004 network: 0.004 permissions: 0.003 socket: 0.003 boot: 0.003 graphic: 0.002 risc-v: 0.002 alpha: 0.002 vnc: 0.001 mistranslation: 0.001 ppc: 0.000 arm: 0.000 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.