SvTRUE(): inline ROK, outline NOK

SvTRUE (and its variants) are wrappers around sv_2bool(), which
attempt to test for the common cases without the overhead of a function
call.

This commit changes the definition of common:

SvROK() becomes common: it's very common to test whether a variable
is undef or a ref;
SvNOK becomes uncommon: these days perl prefers IV values over NV values
in SVs whenever possible, so testing the truth value of an NV is less
common.

1 files changed, 5 insertions, 3 deletions

diff --git a/sv.h b/sv.h
index b80aba1766..ad7046a559 100644
--- a/sv.h
+++ b/sv.h
@@ -1774,9 +1774,11 @@ Like C<sv_utf8_upgrade>, but doesn't do magic on C<sv>.
 	? 0						\
     : SvPOK(sv)						\
 	? SvPVXtrue(sv)					\
-    : (SvFLAGS(sv) & (SVf_IOK|SVf_NOK))			\
-	? (   (SvIOK(sv) && SvIVX(sv) != 0)		\
-	   || (SvNOK(sv) && SvNVX(sv) != 0.0))		\
+    : SvIOK(sv)                			        \
+        ? SvIVX(sv)                                     \
+    : (SvROK(sv) && !(   SvOBJECT(SvRV(sv))             \
+                      && HvAMAGIC(SvSTASH(SvRV(sv)))))  \
+        ? TRUE                                          \
     : (fallback))
 
 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)