grok_bin_oct_hex(): Add branch prediction

1 files changed, 4 insertions, 2 deletions

diff --git a/numeric.c b/numeric.c
index d9e7b3581c..fe5e0f723b 100644
--- a/numeric.c
+++ b/numeric.c
@@ -335,10 +335,12 @@ Perl_grok_bin_oct_hex(pTHX_ const char *start,
         if (_generic_isCC(*s, class_bit)) {
             /* Write it in this wonky order with a goto to attempt to get the
                compiler to make the common case integer-only loop pretty tight.
-               With gcc seems to be much straighter code than old scan_hex.  */
+               With gcc seems to be much straighter code than old scan_hex.
+               (khw suspects that adding a LIKELY() just above would do the
+               same thing) */
           redo:
             if (!overflowed) {
-                if (value <= max_div) {
+                if (LIKELY(value <= max_div)) {
                     value = (value << shift) | XDIGIT_VALUE(*s);
                         /* Note XDIGIT_VALUE() is branchless, works on binary
                          * and octal as well, so can be used here, without