BUILTIN(__builtin_ctzl , "iULi" , "nc")
BUILTIN(__builtin_ctzll, "iULLi", "nc")
// TODO: int ctzimax(uintmax_t)
-BUILTIN(__builtin_ffs , "iUi" , "nc")
-BUILTIN(__builtin_ffsl , "iULi" , "nc")
-BUILTIN(__builtin_ffsll, "iULLi", "nc")
+BUILTIN(__builtin_ffs , "ii" , "nc")
+BUILTIN(__builtin_ffsl , "iLi" , "nc")
+BUILTIN(__builtin_ffsll, "iLLi", "nc")
BUILTIN(__builtin_parity , "iUi" , "nc")
BUILTIN(__builtin_parityl , "iULi" , "nc")
BUILTIN(__builtin_parityll, "iULLi", "nc")
extern unsigned int __builtin_ia32_crc32qi (unsigned int, unsigned char);
extern unsigned int __builtin_ia32_crc32hi (unsigned int, unsigned short);
extern unsigned int __builtin_ia32_crc32si (unsigned int, unsigned int);
+
+// GCC documents these as unsigned, but they are defined with a signed argument.
+extern int __builtin_ffs(int);
+extern int __builtin_ffsl(long);
+extern int __builtin_ffsll(long long);