Create fcn for lossless conversion of NV to IV

Essentially the same code was being used in three places, and had
undefined C behavior for some inputs.

This consolidates the code into one inline function, and rewrites it to
avoid undefined behavior.

1 files changed, 2 insertions, 8 deletions

diff --git a/pp_hot.c b/pp_hot.c
index 7d5ffc02fd..2df5df8303 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1435,16 +1435,10 @@ PP(pp_add)
             NV nl = SvNVX(svl);
             NV nr = SvNVX(svr);
 
-            if (
-#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
-                !Perl_isnan(nl) && nl == (NV)(il = (IV)nl)
-                && !Perl_isnan(nr) && nr == (NV)(ir = (IV)nr)
-#else
-                nl == (NV)(il = (IV)nl) && nr == (NV)(ir = (IV)nr)
-#endif
-                )
+            if (lossless_NV_to_IV(nl, &il) && lossless_NV_to_IV(nr, &ir)) {
                 /* nothing was lost by converting to IVs */
                 goto do_iv;
+            }
             SP--;
             TARGn(nl + nr, 0); /* args not GMG, so can't be tainted */
             SETs(TARG);