create Perl_hv_pushkv() function

...and make pp_padhv(), pp_rv2hv() use it rather than using Perl_do_kv()

Both pp_padhv() and pp_rv2hv() (via S_padhv_rv2hv_common()), outsource to
Perl_do_kv(), the list-context pushing/flattening of a hash onto the
stack.

Perl_do_kv() is a big function that handles all the actions of
keys, values etc. Instead, create a new function which does just the
pushing of a hash onto the stack.

At the same time, split it out into two loops, one for tied, one for
normal: the untied one can skip extending the stack on each iteration,
and use a cheaper HeVAL() instead of calling hv_iterval().

1 files changed, 44 insertions, 0 deletions

diff --git a/hv.c b/hv.c
index 1c339d5c73..37518c4ff4 100644
--- a/hv.c
+++ b/hv.c
@@ -967,6 +967,50 @@ Perl_hv_scalar(pTHX_ HV *hv)
     return sv;
 }
 
+
+/*
+Pushes all the keys and values of a hash onto the stack.
+Resets the hash's iterator.
+The rough Perl equivalent: C< () = %hash; >
+XXX this may at some point be extended to push 'keys %h' and 'values %h'
+too. I might also unroll hv_iternext() - DAPM
+*/
+
+void
+Perl_hv_pushkv(pTHX_ HV *hv)
+{
+    HE *entry;
+    bool tied = SvRMAGICAL(hv) && mg_find(MUTABLE_SV(hv), PERL_MAGIC_tied);
+    dSP;
+
+    PERL_ARGS_ASSERT_HV_PUSHKV;
+
+    (void)hv_iterinit(hv);
+
+    if (tied) {
+        while ((entry = hv_iternext(hv))) {
+            EXTEND(SP, 2);
+            PUSHs(hv_iterkeysv(entry));
+            PUSHs(hv_iterval(hv, entry));
+        }
+    }
+    else {
+        SSize_t extend_size;
+        /* 2*HvUSEDKEYS() should never be big enough to truncate or wrap */
+        assert(HvUSEDKEYS(hv) <= (SSize_t_MAX >> 1));
+        extend_size = (SSize_t)HvUSEDKEYS(hv) * 2;
+        EXTEND(SP, extend_size);
+
+        while ((entry = hv_iternext(hv))) {
+            PUSHs(hv_iterkeysv(entry));
+            PUSHs(HeVAL(entry));
+        }
+    }
+
+    PUTBACK;
+}
+
+
 /*
 =for apidoc hv_bucket_ratio