diff options
| -rw-r--r-- | av.c | 21 |
1 files changed, 14 insertions, 7 deletions
@@ -244,6 +244,9 @@ S_adjust_index(pTHX_ AV *av, const MAGIC *mg, SSize_t *keyp) SV** Perl_av_fetch(pTHX_ AV *av, SSize_t key, I32 lval) { + SSize_t neg; + SSize_t size; + PERL_ARGS_ASSERT_AV_FETCH; assert(SvTYPE(av) == SVt_PVAV); @@ -268,15 +271,19 @@ Perl_av_fetch(pTHX_ AV *av, SSize_t key, I32 lval) } } - if (key < 0) { - key += AvFILLp(av) + 1; - if (UNLIKELY(key < 0)) + neg = (key < 0); + size = AvFILLp(av) + 1; + key += neg * size; /* handle negative index without using branch */ + + /* the cast from SSize_t to Size_t allows both (key < 0) and (key >= size) + * to be tested as a single condition */ + if ((Size_t)key >= (Size_t)size) { + if (UNLIKELY(neg)) return NULL; - assert(key <= AvFILLp(av)); - if (!AvARRAY(av)[key]) - goto emptyness; + goto emptyness; } - else if (key > AvFILLp(av) || !AvARRAY(av)[key]) { + + if (!AvARRAY(av)[key]) { emptyness: return lval ? av_store(av,key,newSV(0)) : NULL; } |