src/etc/platform-intrinsics/x86/bmi.json

{
    "intrinsic_prefix": "_bmi",
    "llvm_prefix": "llvm.x86.bmi.",
    "intrinsics": [
        {
            "intrinsic": "_bextr_{0.bitwidth}",
            "width": ["0"],
            "llvm": "bextr.{0.bitwidth}",
            "ret": "S(32-64)u",
            "args": ["0", "0"]
        }
    ]
}