reduce cost of SvVALID()

Now that SvVALID() no longer just checks an SV flag, but instead checks
for the existence of a certain type of magic, avoid using this more
expensive macro when its not really needed.

Also, and an extra flag test to SvVALID() to make it fail quicker.

1 files changed, 3 insertions, 2 deletions

diff --git a/util.c b/util.c
index fb2ddec974..88f1700431 100644
--- a/util.c
+++ b/util.c
@@ -811,7 +811,8 @@ Perl_fbm_instr(pTHX_ unsigned char *big, unsigned char *bigend, SV *littlestr, U
     const unsigned char *little = (const unsigned char *)SvPV_const(littlestr,l);
     STRLEN littlelen = l;
     const I32 multiline = flags & FBMrf_MULTILINE;
-    bool tail = SvVALID(littlestr) ? cBOOL(SvTAIL(littlestr)) : FALSE;
+    bool valid = SvVALID(littlestr);
+    bool tail = valid ? cBOOL(SvTAIL(littlestr)) : FALSE;
 
     PERL_ARGS_ASSERT_FBM_INSTR;
 
@@ -945,7 +946,7 @@ Perl_fbm_instr(pTHX_ unsigned char *big, unsigned char *bigend, SV *littlestr, U
 	return NULL;
     }
 
-    if (!SvVALID(littlestr)) {
+    if (!valid) {
         /* not compiled; use Perl_ninstr() instead */
 	char * const b = ninstr((char*)big,(char*)bigend,
 			 (char*)little, (char*)little + littlelen);