{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
                    let b_lane_masked = fx.bcx.ins().band_imm(b_lane, 0xf);
                    let is_zero = fx.bcx.ins().band_imm(b_lane, 0x80);
                    let a_idx = fx.bcx.ins().iadd_imm(b_lane_masked, 16);