Perl_newSV_type_mortal - new inline function introduced and used

There's no efficient way to create a mortal SV of any type other than
SVt_NULL (via sv_newmortal). The options are either to do:

* SV* sv = sv_newmortal; sv_upgrade(sv, SVt_SOMETYPE);
  but sv_upgrade is needlessly inefficient on new SVs.

* SV* sv = sv_2mortal(newSV_type(SVt_SOMETYPE)
  but this will perform runtime checks to see if (sv) and if (SvIMMORTAL(sv),
  and for a new SV we know that those answers will always be yes and no.

This commit adds a new inline function which is basically a mortalizing
wrapper around the now-inlined newSV_type.

av.c

@@ -267,8 +267,7 @@ Perl_av_fetch(pTHX_ AV *av, SSize_t key, I32 lval)
                         return NULL;
             }
 
-            sv = sv_newmortal();
-            sv_upgrade(sv, SVt_PVLV);
+            sv = newSV_type_mortal(SVt_PVLV);
             mg_copy(MUTABLE_SV(av), sv, 0, key);
             if (!tied_magic) /* for regdata, force leavesub to make copies */
                 SvTEMP_off(sv);

doop.c

@@ -1176,7 +1176,7 @@ Perl_do_kv(pTHX)
 
     if (gimme == G_SCALAR) {
         if (PL_op->op_flags & OPf_MOD || LVRET) {	/* lvalue */
-            SV * const ret = sv_2mortal(newSV_type(SVt_PVLV));  /* Not TARG RT#67838 */
+            SV * const ret = newSV_type_mortal(SVt_PVLV);  /* Not TARG RT#67838 */
             sv_magic(ret, NULL, PERL_MAGIC_nkeys, NULL, 0);
             LvTYPE(ret) = 'k';
             LvTARG(ret) = SvREFCNT_inc_simple(keys);

embed.fnc

@@ -1520,6 +1520,7 @@ ApMbdR	|SV*	|newSVsv	|NULLOK SV *const old
 AmdR	|SV*	|newSVsv_nomg	|NULLOK SV *const old
 AdpR	|SV*	|newSVsv_flags	|NULLOK SV *const old|I32 flags
 ApdiR	|SV*	|newSV_type	|const svtype type
+ApdIR	|SV*    |newSV_type_mortal|const svtype type
 ApdR	|OP*	|newUNOP	|I32 type|I32 flags|NULLOK OP* first
 ApdR	|OP*	|newUNOP_AUX	|I32 type|I32 flags|NULLOK OP* first \
 				|NULLOK UNOP_AUX_item *aux

embed.h

@@ -386,6 +386,7 @@
 #define newSVOP(a,b,c)		Perl_newSVOP(aTHX_ a,b,c)
 #define newSVREF(a)		Perl_newSVREF(aTHX_ a)
 #define newSV_type(a)		Perl_newSV_type(aTHX_ a)
+#define newSV_type_mortal(a)	Perl_newSV_type_mortal(aTHX_ a)
 #define newSVhek(a)		Perl_newSVhek(aTHX_ a)
 #define newSViv(a)		Perl_newSViv(aTHX_ a)
 #define newSVnv(a)		Perl_newSVnv(aTHX_ a)

gv.c

@@ -3801,7 +3801,7 @@ Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
             break;
         case G_LIST:
             if (flags & AMGf_want_list) {
-                res = sv_2mortal((SV *)newAV());
+                res = newSV_type_mortal(SVt_PVAV);
                 av_extend((AV *)res, nret);
                 while (nret--)
                     av_store((AV *)res, nret, POPs);

hv.c

@@ -200,12 +200,12 @@ static void
 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
                 const char *msg)
 {
-    SV * const sv = sv_newmortal();
+   /* Straight to SVt_PVN here, as needed by sv_setpvn_fresh and
+    * sv_usepvn would otherwise call it */
+    SV * const sv = newSV_type_mortal(SVt_PV);
 
     PERL_ARGS_ASSERT_HV_NOTALLOWED;
 
-    sv_upgrade(sv, SVt_PV); /* Needed by sv_setpvn_fresh and
-                             * sv_usepvn would otherwise call it */
     if (!(flags & HVhek_FREEKEY)) {
         sv_setpvn_fresh(sv, key, klen);
     }
@@ -968,6 +968,7 @@ SV *
 Perl_hv_scalar(pTHX_ HV *hv)
 {
     SV *sv;
+    UV u;
 
     PERL_ARGS_ASSERT_HV_SCALAR;
 
@@ -977,8 +978,21 @@ Perl_hv_scalar(pTHX_ HV *hv)
             return magic_scalarpack(hv, mg);
     }
 
-    sv = sv_newmortal();
-    sv_setuv(sv, HvUSEDKEYS(hv));
+    sv = newSV_type_mortal(SVt_IV);
+
+    /* Inlined sv_setuv(sv, HvUSEDKEYS(hv)) follows:*/
+    u = HvUSEDKEYS(hv);
+
+    if (u <= (UV)IV_MAX) {
+        SvIV_set(sv, (IV)u);
+        (void)SvIOK_only(sv);
+        SvTAINT(sv);
+    } else {
+        SvIV_set(sv, 0);
+        SvUV_set(sv, u);
+        (void)SvIOK_only_UV(sv);
+        SvTAINT(sv);
+    }
 
     return sv;
 }

mg.c

@@ -877,7 +877,7 @@ Perl_sv_string_from_errnum(pTHX_ int errnum, SV *tgtsv)
 {
     char const *errstr;
     if(!tgtsv)
-        tgtsv = sv_newmortal();
+        tgtsv = newSV_type_mortal(SVt_PV);
     errstr = my_strerror(errnum);
     if(errstr) {
         sv_setpv(tgtsv, errstr);

mro_core.c

@@ -255,7 +255,7 @@ S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level)
 
     /* not in cache, make a new one */
 
-    retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV())));
+    retval = MUTABLE_AV(newSV_type_mortal(SVt_PVAV));
     /* We use this later in this function, but don't need a reference to it
        beyond the end of this function, so reference count is fine.  */
     our_name = newSVhek(stashhek);
@@ -347,7 +347,7 @@ S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level)
                 } else {
                     /* They have no stash.  So create ourselves an ->isa cache
                        as if we'd copied it from what theirs should be.  */
-                    stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV())));
+                    stored = MUTABLE_HV(newSV_type_mortal(SVt_PVHV));
                     (void) hv_stores(stored, "UNIVERSAL", &PL_sv_undef);
                     av_push(retval,
                             newSVhek(HeKEY_hek(hv_store_ent(stored, sv,
@@ -357,7 +357,7 @@ S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level)
         }
     } else {
         /* We have no parents.  */
-        stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV())));
+        stored = MUTABLE_HV(newSV_type_mortal(SVt_PVHV));
         (void) hv_stores(stored, "UNIVERSAL", &PL_sv_undef);
     }
 
@@ -428,7 +428,7 @@ Perl_mro_get_linear_isa(pTHX_ HV *stash)
             SV **svp;
             SV **ovp = AvARRAY(old);
             SV * const * const oend = ovp + AvFILLp(old) + 1;
-            isa = (AV *)sv_2mortal((SV *)newAV());
+            isa = (AV *)newSV_type_mortal(SVt_PVAV);
             av_extend(isa, AvFILLp(isa) = AvFILLp(old)+1);
             *AvARRAY(isa) = namesv;
             svp = AvARRAY(isa)+1;
@@ -570,7 +570,7 @@ Perl_mro_isa_changed_in(pTHX_ HV* stash)
         if(hv_iterinit(isarev)) {
             /* Only create the hash if we need it; i.e., if isarev has
                any elements. */
-            isa_hashes = (HV *)sv_2mortal((SV *)newHV());
+            isa_hashes = (HV *)newSV_type_mortal(SVt_PVHV);
         }
         while((iter = hv_iternext(isarev))) {
             HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0);
@@ -817,7 +817,7 @@ Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash,
     }
     else {
         SV *aname;
-        namesv = sv_2mortal((SV *)newAV());
+        namesv = newSV_type_mortal(SVt_PVAV);
         while (name_count--) {
             if(memEQs(HEK_KEY(*namep), HEK_LEN(*namep), "main")){
                 aname = GvNAMELEN(gv) == 1
@@ -854,9 +854,9 @@ Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash,
        wrong name. The names must be set on *all* affected stashes before
        we do anything else. (And linearisations must be cleared, too.)
      */
-    stashes = (HV *) sv_2mortal((SV *)newHV());
+    stashes = (HV *) newSV_type_mortal(SVt_PVHV);
     mro_gather_and_rename(
-     stashes, (HV *) sv_2mortal((SV *)newHV()),
+     stashes, (HV *) newSV_type_mortal(SVt_PVHV),
      stash, oldstash, namesv
     );
 
@@ -1119,7 +1119,7 @@ S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes,
     /* Skip the entire loop if the hash is empty.   */
     if(oldstash && HvTOTALKEYS(oldstash)) {
         xhv = (XPVHV*)SvANY(oldstash);
-        seen = (HV *) sv_2mortal((SV *)newHV());
+        seen = (HV *) newSV_type_mortal(SVt_PVHV);
 
         /* Iterate through entries in the oldstash, adding them to the
            list, meanwhile doing the equivalent of $seen{$key} = 1.
@@ -1164,7 +1164,7 @@ S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes,
                             SV *aname;
                             items = AvFILLp((AV *)namesv) + 1;
                             svp = AvARRAY((AV *)namesv);
-                            subname = sv_2mortal((SV *)newAV());
+                            subname = newSV_type_mortal(SVt_PVAV);
                             while (items--) {
                                 aname = newSVsv(*svp++);
                                 if (len == 1)
@@ -1247,7 +1247,7 @@ S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes,
                             SV *aname;
                             items = AvFILLp((AV *)namesv) + 1;
                             svp = AvARRAY((AV *)namesv);
-                            subname = sv_2mortal((SV *)newAV());
+                            subname = newSV_type_mortal(SVt_PVAV);
                             while (items--) {
                                 aname = newSVsv(*svp++);
                                 if (len == 1)

pad.c

@@ -1252,13 +1252,13 @@ S_pad_findlex(pTHX_ const char *namepv, STRLEN namelen, U32 flags, const CV* cv,
                 }
                 if (!*out_capture) {
                     if (namelen != 0 && *namepv == '@')
-                        *out_capture = sv_2mortal(MUTABLE_SV(newAV()));
+                        *out_capture = newSV_type_mortal(SVt_PVAV);
                     else if (namelen != 0 && *namepv == '%')
-                        *out_capture = sv_2mortal(MUTABLE_SV(newHV()));
+                        *out_capture = newSV_type_mortal(SVt_PVHV);
                     else if (namelen != 0 && *namepv == '&')
-                        *out_capture = sv_2mortal(newSV_type(SVt_PVCV));
+                        *out_capture = newSV_type_mortal(SVt_PVCV);
                     else
-                        *out_capture = sv_newmortal();
+                        *out_capture = newSV_type_mortal(SVt_NULL);
                 }
             }
 
@@ -2063,7 +2063,7 @@ S_cv_clone_pad(pTHX_ CV *proto, CV *cv, CV *outside, HV *cloned,
              */
             bool cloned_in_this_pass;
             if (!cloned)
-                cloned = (HV *)sv_2mortal((SV *)newHV());
+                cloned = (HV *)newSV_type_mortal(SVt_PVHV);
             do {
                 cloned_in_this_pass = FALSE;
                 for (ix = fpad; ix > 0; ix--) {

pp.c

@@ -313,7 +313,7 @@ PP(pp_pos)
     dSP; dTOPss;
 
     if (PL_op->op_flags & OPf_MOD || LVRET) {
-        SV * const ret = sv_2mortal(newSV_type(SVt_PVLV));/* Not TARG RT#67838 */
+        SV * const ret = newSV_type_mortal(SVt_PVLV);/* Not TARG RT#67838 */
         sv_magic(ret, NULL, PERL_MAGIC_pos, NULL, 0);
         LvTYPE(ret) = '.';
         LvTARG(ret) = SvREFCNT_inc_simple(sv);
@@ -467,7 +467,7 @@ S_refto(pTHX_ SV *sv)
         SvTEMP_off(sv);
         SvREFCNT_inc_void_NN(sv);
     }
-    rv = sv_newmortal();
+    rv = newSV_type_mortal(SVt_IV);
     sv_setrv_noinc(rv, sv);
     return rv;
 }
@@ -3300,7 +3300,7 @@ PP(pp_substr)
     }
     if (lvalue && !repl_sv) {
         SV * ret;
-        ret = sv_2mortal(newSV_type(SVt_PVLV));  /* Not TARG RT#67838 */
+        ret = newSV_type_mortal(SVt_PVLV);  /* Not TARG RT#67838 */
         sv_magic(ret, NULL, PERL_MAGIC_substr, NULL, 0);
         LvTYPE(ret) = 'x';
         LvTARG(ret) = SvREFCNT_inc_simple(sv);
@@ -3432,7 +3432,7 @@ PP(pp_vec)
     retuv = errflags ? 0 : do_vecget(src, offset, size);
 
     if (lvalue) {			/* it's an lvalue! */
-        ret = sv_2mortal(newSV_type(SVt_PVLV));  /* Not TARG RT#67838 */
+        ret = newSV_type_mortal(SVt_PVLV);  /* Not TARG RT#67838 */
         sv_magic(ret, NULL, PERL_MAGIC_vec, NULL, 0);
         LvTYPE(ret) = 'v';
         LvTARG(ret) = SvREFCNT_inc_simple(src);
@@ -6830,7 +6830,7 @@ PP(pp_refassign)
 PP(pp_lvref)
 {
     dSP;
-    SV * const ret = sv_2mortal(newSV_type(SVt_PVMG));
+    SV * const ret = newSV_type_mortal(SVt_PVMG);
     SV * const elem = PL_op->op_private & OPpLVREF_ELEM ? POPs : NULL;
     SV * const arg = PL_op->op_flags & OPf_STACKED ? POPs : NULL;
     MAGIC * const mg = sv_magicext(ret, arg, PERL_MAGIC_lvref,
@@ -6898,7 +6898,7 @@ PP(pp_lvrefslice)
             else
                 S_localise_helem_lval(aTHX_ (HV *)av, elemsv, can_preserve);
         }
-        *MARK = sv_2mortal(newSV_type(SVt_PVMG));
+        *MARK = newSV_type_mortal(SVt_PVMG);
         sv_magic(*MARK,(SV *)av,PERL_MAGIC_lvref,(char *)elemsv,HEf_SVKEY);
     }
     RETURN;

pp_ctl.c

@@ -5169,12 +5169,10 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other, const bool copied)
                 const Size_t other_len = av_count(other_av);
 
                 if (NULL == seen_this) {
-                    seen_this = newHV();
-                    (void) sv_2mortal(MUTABLE_SV(seen_this));
+                    seen_this = (HV*)newSV_type_mortal(SVt_PVHV);
                 }
                 if (NULL == seen_other) {
-                    seen_other = newHV();
-                    (void) sv_2mortal(MUTABLE_SV(seen_other));
+                    seen_other = (HV*)newSV_type_mortal(SVt_PVHV);
                 }
                 for(i = 0; i < other_len; ++i) {
                     SV * const * const this_elem = av_fetch(MUTABLE_AV(SvRV(e)), i, FALSE);
@@ -5882,7 +5880,7 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
        don't want to pass it in a second time.
        I'm going to use a mortal in case the upstream filter croaks.  */
     upstream = ((SvOK(buf_sv) && sv_len(buf_sv)) || SvGMAGICAL(buf_sv))
-        ? sv_newmortal() : buf_sv;
+        ? newSV_type_mortal(SVt_PV) : buf_sv;
     SvUPGRADE(upstream, SVt_PV);
 
     if (filter_has_file) {

pp_hot.c

@@ -991,7 +991,7 @@ PP(pp_multiconcat)
                    )
             )
             {
-                SV *tmp = sv_newmortal();
+                SV *tmp = newSV_type_mortal(SVt_PV);
                 sv_copypv(tmp, left);
                 SvSETMAGIC(tmp);
                 left = tmp;
@@ -2868,7 +2868,7 @@ PP(pp_qr)
     REGEXP * rx = PM_GETRE(pm);
     regexp *prog = ReANY(rx);
     SV * const pkg = RXp_ENGINE(prog)->qr_package(aTHX_ (rx));
-    SV * const rv = sv_newmortal();
+    SV * const rv = newSV_type_mortal(SVt_IV);
     CV **cvp;
     CV *cv;
 
@@ -3406,8 +3406,7 @@ PP(pp_helem)
             if (!defer) {
                 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
             }
-            lv = sv_newmortal();
-            sv_upgrade(lv, SVt_PVLV);
+            lv = newSV_type_mortal(SVt_PVLV);
             LvTYPE(lv) = 'y';
             sv_magic(lv, key2 = newSVsv(keysv), PERL_MAGIC_defelem, NULL, 0);
             SvREFCNT_dec_NN(key2);	/* sv_magic() increments refcount */
@@ -3846,8 +3845,7 @@ PP(pp_multideref)
                             SV* key2;
                             if (!defer)
                                 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
-                            lv = sv_newmortal();
-                            sv_upgrade(lv, SVt_PVLV);
+                            lv = newSV_type_mortal(SVt_PVLV);
                             LvTYPE(lv) = 'y';
                             sv_magic(lv, key2 = newSVsv(keysv),
                                                 PERL_MAGIC_defelem, NULL, 0);

proto.h

@@ -2488,6 +2488,13 @@ PERL_STATIC_INLINE SV*	Perl_newSV_type(pTHX_ const svtype type)
 #define PERL_ARGS_ASSERT_NEWSV_TYPE
 #endif
 
+#ifndef PERL_NO_INLINE_FUNCTIONS
+PERL_STATIC_FORCE_INLINE SV*	Perl_newSV_type_mortal(pTHX_ const svtype type)
+			__attribute__warn_unused_result__
+			__attribute__always_inline__;
+#define PERL_ARGS_ASSERT_NEWSV_TYPE_MORTAL
+#endif
+
 PERL_CALLCONV SV*	Perl_newSVavdefelem(pTHX_ AV *av, SSize_t ix, bool extendible)
 			__attribute__warn_unused_result__;
 #define PERL_ARGS_ASSERT_NEWSVAVDEFELEM	\

regcomp.c

@@ -16673,8 +16673,8 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
      * so that everything gets evaluated down to a single operand, which is the
      * result */
 
-    sv_2mortal((SV *)(stack = newAV()));
-    sv_2mortal((SV *)(fence_stack = newAV()));
+    stack = (AV*)newSV_type_mortal(SVt_PVAV);
+    fence_stack = (AV*)newSV_type_mortal(SVt_PVAV);
 
     while (RExC_parse < RExC_end) {
         I32 top_index;              /* Index of top-most element in 'stack' */