libbb: use narrow isqrt() when 64-bit one is not needed (only "factor" uses it)

function                                             old     new   delta
isqrt_ull                                              -      84     +84
create_J                                            1809    1808      -1
isqrt                                                106      38     -68
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 84/-69)             Total: 15 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/libbb.h b/include/libbb.h
index aacff42ee..7cca925b9 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -408,7 +408,12 @@ unsigned FAST_FUNC bb_popcnt_long(unsigned long m);
 #define bb_popcnt_long(m) bb_popcnt_32(m)
 #endif
 
-unsigned long FAST_FUNC isqrt(unsigned long long N);
+unsigned FAST_FUNC isqrt(unsigned long N);
+#if LLONG_MAX > LONG_MAX
+unsigned long FAST_FUNC isqrt_ull(unsigned long long N);
+#else
+# define isqrt_ull(N) isqrt(N)
+#endif
 
 unsigned long long monotonic_ns(void) FAST_FUNC;
 unsigned long long monotonic_us(void) FAST_FUNC;