Investigation reveals that the work of restoring the iterator to the

pad is shared between POPLOOP, using itersave, and the end of scope
restore action requested by Perl_save_padsv(). In fact, the only user
of SAVEt_PADSV is pp_enteriter, and it already provides enough
information to allow it to perform the sv_2mortal() in POPLOOP.
So make it do so. Rather than creating a new routine, use the existing
routine because nothing else (at least nothing else known to Google's
codesearch) uses it. But rename it just in case something we can't see
is being naughty and using our private functions - they will get
link errors against 5.12.

All this means that itersave is now redundant. So remove it.
This makes struct context 48 bytes on ILP32 platforms with 32bit IVs,
down from 64 bytes in 5.10. 33% more context stack in the same memory.

p4raw-id: //depot/perl@33080

diff --git a/cop.h b/cop.h
index ca9dae286e7c5db81c3d1c5263b267e7cfd8d3c0..4af6b8f74ceeef4e296942bdf4669710a63441fb 100644 (file)
--- a/cop.h
+++ b/cop.h
@@ -442,7 +442,6 @@ struct block_loop {
     OP *       next_op;
     SV **      itervar;
 #endif
-    SV *       itersave;
     union {
        struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
            AV * ary; /* use the stack if this is NULL */
@@ -469,18 +468,11 @@ struct block_loop {
         : (SV**)NULL)
 #  define CX_ITERDATA_SET(cx,idata)                                    \
        CX_CURPAD_SAVE(cx->blk_loop);                                   \
-       if ((cx->blk_loop.iterdata = (idata)) && SvPADMY(*CxITERVAR(cx))) \
-           cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
-       else                                                            \
-           cx->blk_loop.itersave = NULL;
+       cx->blk_loop.iterdata = (idata);
 #else
 #  define CxITERVAR(c)         ((c)->blk_loop.itervar)
 #  define CX_ITERDATA_SET(cx,ivar)                                     \
-       if ((cx->blk_loop.itervar = (SV**)(ivar))                       \
-           && SvPADMY(*CxITERVAR(cx)))                                 \
-           cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
-       else                                                            \
-           cx->blk_loop.itersave = NULL;
+       cx->blk_loop.itervar = (SV**)(ivar);
 #endif
 #define CxLABEL(c)     (0 + (c)->blk_oldcop->cop_label)
 #define CxHASARGS(c)   (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
@@ -515,12 +507,6 @@ struct block_loop {
            SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
            SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
        }                                                               \
-       if (cx->blk_loop.itersave) {                                    \
-           SV ** const s_v_p = CxITERVAR(cx);                          \
-           assert(SvPADMY(cx->blk_loop.itersave));                     \
-           sv_2mortal(*s_v_p);                                         \
-           *s_v_p = cx->blk_loop.itersave;                             \
-       }                                                               \
        if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
            SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
 

diff --git a/embed.fnc b/embed.fnc
index 972e5417674360a38dfd1ce21d100a6357ff7334..ef4ae062cc246abe7a1954c705f07c19089b61c7 100644 (file)
--- a/embed.fnc
+++ b/embed.fnc
@@ -775,7 +775,7 @@ Ap  |SV*    |save_scalar    |NN GV* gv
 Ap     |void   |save_pptr      |NN char** pptr
 Ap     |void   |save_vptr      |NN void* pptr
 Ap     |void   |save_re_context
-Ap     |void   |save_padsv     |PADOFFSET off
+Ap     |void   |save_padsv_and_mortalize|PADOFFSET off
 Ap     |void   |save_sptr      |NN SV** sptr
 Ap     |SV*    |save_svref     |NN SV** sptr
 p      |OP*    |sawparens      |NULLOK OP* o

diff --git a/embed.h b/embed.h
index c0bcae20014ad3c240adbcd3d75743eaf09a4613..8d2d11e18fd5ce13a09dfd8771d83d213d38a870 100644 (file)
--- a/embed.h
+++ b/embed.h
@@ -781,7 +781,7 @@
 #define save_pptr              Perl_save_pptr
 #define save_vptr              Perl_save_vptr
 #define save_re_context                Perl_save_re_context
-#define save_padsv             Perl_save_padsv
+#define save_padsv_and_mortalize       Perl_save_padsv_and_mortalize
 #define save_sptr              Perl_save_sptr
 #define save_svref             Perl_save_svref
 #ifdef PERL_CORE
@@ -3085,7 +3085,7 @@
 #define save_pptr(a)           Perl_save_pptr(aTHX_ a)
 #define save_vptr(a)           Perl_save_vptr(aTHX_ a)
 #define save_re_context()      Perl_save_re_context(aTHX)
-#define save_padsv(a)          Perl_save_padsv(aTHX_ a)
+#define save_padsv_and_mortalize(a)    Perl_save_padsv_and_mortalize(aTHX_ a)
 #define save_sptr(a)           Perl_save_sptr(aTHX_ a)
 #define save_svref(a)          Perl_save_svref(aTHX_ a)
 #ifdef PERL_CORE

diff --git a/pp_ctl.c b/pp_ctl.c
index 5da699358f17fbfbff7faace4194f4c20d235cb7..9c6e2b1e1363025c2faf7bb2b39c6c822e55b591 100644 (file)
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -1849,11 +1849,10 @@ PP(pp_enteriter)
            SAVESETSVFLAGS(PAD_SVl(PL_op->op_targ),
                    SVs_PADSTALE, SVs_PADSTALE);
        }
+       SAVEPADSVANDMORTALIZE(PL_op->op_targ);
 #ifndef USE_ITHREADS
        svp = &PAD_SVl(PL_op->op_targ);         /* "my" variable */
-       SAVESPTR(*svp);
 #else
-       SAVEPADSV(PL_op->op_targ);
        iterdata = INT2PTR(void*, PL_op->op_targ);
        cxtype |= CXp_PADVAR;
 #endif

diff --git a/proto.h b/proto.h
index e1a3647b0e5430d287807941d507f11a9331cbf7..222bd1421777e29b06cfa75d85d3ef9e6d3063b8 100644 (file)
--- a/proto.h
+++ b/proto.h
@@ -2089,7 +2089,7 @@ PERL_CALLCONV void        Perl_save_vptr(pTHX_ void* pptr)
                        __attribute__nonnull__(pTHX_1);
 
 PERL_CALLCONV void     Perl_save_re_context(pTHX);
-PERL_CALLCONV void     Perl_save_padsv(pTHX_ PADOFFSET off);
+PERL_CALLCONV void     Perl_save_padsv_and_mortalize(pTHX_ PADOFFSET off);
 PERL_CALLCONV void     Perl_save_sptr(pTHX_ SV** sptr)
                        __attribute__nonnull__(pTHX_1);
 

diff --git a/scope.c b/scope.c
index 616247e6741d83f0af563a844fdcc91e9612915f..fae4892ab1602e63608b3576cea5db3271bbea30 100644 (file)
--- a/scope.c
+++ b/scope.c
@@ -412,15 +412,15 @@ Perl_save_sptr(pTHX_ SV **sptr)
 }
 
 void
-Perl_save_padsv(pTHX_ PADOFFSET off)
+Perl_save_padsv_and_mortalize(pTHX_ PADOFFSET off)
 {
     dVAR;
     SSCHECK(4);
     ASSERT_CURPAD_ACTIVE("save_padsv");
-    SSPUSHPTR(PL_curpad[off]);
+    SSPUSHPTR(SvREFCNT_inc_simple_NN(PL_curpad[off]));
     SSPUSHPTR(PL_comppad);
     SSPUSHLONG((long)off);
-    SSPUSHINT(SAVEt_PADSV);
+    SSPUSHINT(SAVEt_PADSV_AND_MORTALIZE);
 }
 
 void
@@ -929,12 +929,18 @@ Perl_leave_scope(pTHX_ I32 base)
            else
                PL_curpad = NULL;
            break;
-       case SAVEt_PADSV:
+       case SAVEt_PADSV_AND_MORTALIZE:
            {
                const PADOFFSET off = (PADOFFSET)SSPOPLONG;
+               SV **svp;
                ptr = SSPOPPTR;
-               if (ptr)
-                   assert(AvARRAY((PAD*)ptr)[off] == (SV*)SSPOPPTR);
+               assert (ptr);
+               svp = AvARRAY((PAD*)ptr) + off;
+               /* This mortalizing used to be done by POPLOOP() via itersave.
+                  But as we have all the information here, we can do it here,
+                  save even having to have itersave in the struct.  */
+               sv_2mortal(*svp);
+               *svp = (SV*)SSPOPPTR;
            }
            break;
        case SAVEt_SAVESWITCHSTACK:
@@ -1101,9 +1107,6 @@ Perl_cx_dump(pTHX_ PERL_CONTEXT *cx)
                (long)cx->blk_loop.state_u.ary.ix);
        PerlIO_printf(Perl_debug_log, "BLK_LOOP.ITERVAR = 0x%"UVxf"\n",
                PTR2UV(CxITERVAR(cx)));
-       if (CxITERVAR(cx))
-           PerlIO_printf(Perl_debug_log, "BLK_LOOP.ITERSAVE = 0x%"UVxf"\n",
-               PTR2UV(cx->blk_loop.itersave));
        break;
 
     case CXt_SUBST:

diff --git a/scope.h b/scope.h
index 606fbc23d62994315d3962a94d3f7aaeafec746e..7f56460b2dc016b740d9857bbc4ae512e5cd3f23 100644 (file)
--- a/scope.h
+++ b/scope.h
@@ -43,7 +43,7 @@
 #define SAVEt_I8               32
 #define SAVEt_COMPPAD          33
 #define SAVEt_GENERIC_PVREF    34
-#define SAVEt_PADSV            35
+#define SAVEt_PADSV_AND_MORTALIZE      35
 #define SAVEt_MORTALIZESV      36
 #define SAVEt_SHARED_PVREF     37
 #define SAVEt_BOOL             38
@@ -126,7 +126,7 @@ Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
 #define SAVESPTR(s)    save_sptr((SV**)&(s))
 #define SAVEPPTR(s)    save_pptr((char**)&(s))
 #define SAVEVPTR(s)    save_vptr((void*)&(s))
-#define SAVEPADSV(s)   save_padsv(s)
+#define SAVEPADSVANDMORTALIZE(s)       save_padsv_and_mortalize(s)
 #define SAVEFREESV(s)  save_freesv((SV*)(s))
 #define SAVEMORTALIZESV(s)     save_mortalizesv((SV*)(s))
 #define SAVEFREEOP(o)  save_freeop((OP*)(o))

diff --git a/sv.c b/sv.c
index 925b83e2939bb28332e4a4ccde3a13ccaa367819..6d60eebdb554489d89b9de9d2d93eeed624a404f 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -10564,8 +10564,6 @@ Perl_cx_dup(pTHX_ PERL_CONTEXT *cxs, I32 ix, I32 max, CLONE_PARAMS* param)
                ncx->blk_loop.oldcomppad
                    = (PAD*)ptr_table_fetch(PL_ptr_table,
                                            ncx->blk_loop.oldcomppad);
-               ncx->blk_loop.itersave  = sv_dup_inc(ncx->blk_loop.itersave,
-                                                    param);
                break;
            case CXt_FORMAT:
                ncx->blk_format.cv      = cv_dup(ncx->blk_format.cv, param);
@@ -10874,13 +10872,13 @@ Perl_ss_dup(pTHX_ PerlInterpreter *proto_perl, CLONE_PARAMS* param)
                TOPPTR(nss,ix) = hv_dup_inc(hv, param);
            }
            break;
-       case SAVEt_PADSV:
+       case SAVEt_PADSV_AND_MORTALIZE:
            longval = (long)POPLONG(ss,ix);
            TOPLONG(nss,ix) = longval;
            ptr = POPPTR(ss,ix);
            TOPPTR(nss,ix) = any_dup(ptr, proto_perl);
            sv = (SV*)POPPTR(ss,ix);
-           TOPPTR(nss,ix) = sv_dup(sv, param);
+           TOPPTR(nss,ix) = sv_dup_inc(sv, param);
            break;
        case SAVEt_BOOL:
            ptr = POPPTR(ss,ix);