Function `svcvtx_f32_f64_m`

#[target_feature(enable = "sve", enable = "sve2")]
pub fn svcvtx_f32_f64_m(inactive: svfloat32_t, pg: svbool_t, op: svfloat64_t) -> svfloat32_t

Down convert, rounding to odd Arm's documentation