ref: 0184094beffb581a783c037aadbb4301c4e85f71 dir: jxl/builtins.arm64.s
TEXT __builtin_ctz(SB),1,$0 RBITW R0, R0 CLZW R0, R0 RETURN TEXT __builtin_clz(SB),1,$0 CLZW R0, R0 RETURN TEXT __builtin_clzll(SB),1,$0 CLZ R0, R0 RETURN