From 7faeda8ddb4f17c21f1c05bb349464a70a4358de Mon Sep 17 00:00:00 2001
From: Richard Leach <richardleach@users.noreply.github.com>
Date: Mon, 19 Apr 2021 21:28:01 +0100
Subject: [PATCH] Perl_clear_defarray: faster array creation via new
 macro+function

---
 av.c     | 2 +-
 pp_hot.c | 7 +++----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/av.c b/av.c
index 041fc32ac32b..afac896dda8d 100644
--- a/av.c
+++ b/av.c
@@ -418,7 +418,7 @@ Perl_av_new_alloc(pTHX_ SSize_t size, bool zeroflag)
     AV * const av = newAV();
     SV** ary;
     PERL_ARGS_ASSERT_AV_NEW_ALLOC;
-    assert(size > 1);
+    assert(size > 0);
 
     Newx(ary, size, SV*); /* Newx performs the memwrap check */
     AvALLOC(av) = ary;
diff --git a/pp_hot.c b/pp_hot.c
index 5119638b9ff6..e7f688ad1b97 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -4966,8 +4966,6 @@ PP(pp_leavesub)
 void
 Perl_clear_defarray(pTHX_ AV* av, bool abandon)
 {
-    const SSize_t fill = AvFILLp(av);
-
     PERL_ARGS_ASSERT_CLEAR_DEFARRAY;
 
     if (LIKELY(!abandon && SvREFCNT(av) == 1 && !SvMAGICAL(av))) {
@@ -4975,8 +4973,9 @@ Perl_clear_defarray(pTHX_ AV* av, bool abandon)
         AvREIFY_only(av);
     }
     else {
-        AV *newav = newAV();
-        av_extend(newav, fill);
+        const SSize_t size = AvFILLp(av) + 1;
+        /* The ternary gives consistency with av_extend() */
+        AV *newav = newAV_alloc_x(size < 4 ? 4 : size);
         AvREIFY_only(newav);
         PAD_SVl(0) = MUTABLE_SV(newav);
         SvREFCNT_dec_NN(av);