Add a new macro SvPV_free() which undoes OOK and free()s the PVX(),

becase there's a lot of code around that calls SvOOK_off(), memmov()s
the buffer, then promptly free()s it. So avoid the needless memmov().

p4raw-id: //depot/perl@24348

6 files changed, 29 insertions, 36 deletions

diff --git a/perl.c b/perl.c
index dfd5f83355..96f5b2dba2 100644
--- a/perl.c
+++ b/perl.c
@@ -957,8 +957,7 @@ perl_destruct(pTHXx)
 	    }
 	}
 	/* we know that type >= SVt_PV */
-	SvOOK_off(PL_mess_sv);
-	Safefree(SvPVX(PL_mess_sv));
+	SvPV_free(PL_mess_sv);
 	Safefree(SvANY(PL_mess_sv));
 	Safefree(PL_mess_sv);
 	PL_mess_sv = Nullsv;
diff --git a/pp.c b/pp.c
index ca4f61d4cb..4500c575de 100644
--- a/pp.c
+++ b/pp.c
@@ -175,9 +175,7 @@ PP(pp_rv2gv)
 		    if (SvTYPE(sv) < SVt_RV)
 			sv_upgrade(sv, SVt_RV);
 		    if (SvPVX(sv)) {
-			SvOOK_off(sv);		/* backoff */
-			if (SvLEN(sv))
-			    Safefree(SvPVX(sv));
+			SvPV_free(sv);
 			SvLEN_set(sv, 0);
                         SvCUR_set(sv, 0);
 		    }
@@ -825,8 +823,7 @@ PP(pp_undef)
 	break;
     default:
 	if (SvTYPE(sv) >= SVt_PV && SvPVX(sv) && SvLEN(sv)) {
-	    SvOOK_off(sv);
-	    Safefree(SvPVX(sv));
+	    SvPV_free(sv);
 	    SvPV_set(sv, Nullch);
 	    SvLEN_set(sv, 0);
 	}
diff --git a/pp_ctl.c b/pp_ctl.c
index 2db8d7e051..783a59a7b5 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -240,9 +240,7 @@ PP(pp_substcont)
 	    } else
 #endif
 	    {
-		SvOOK_off(targ);
-		if (SvLEN(targ))
-		    Safefree(SvPVX(targ));
+		SvPV_free(targ);
 	    }
 	    SvPV_set(targ, SvPVX(dstr));
 	    SvCUR_set(targ, SvCUR(dstr));
diff --git a/pp_hot.c b/pp_hot.c
index 767188be9a..97d7e28868 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -2251,9 +2251,7 @@ PP(pp_subst)
 	} else
 #endif
 	{
-	    SvOOK_off(TARG);
-	    if (SvLEN(TARG))
-		Safefree(SvPVX(TARG));
+	    SvPV_free(TARG);
 	}
 	SvPV_set(TARG, SvPVX(dstr));
 	SvCUR_set(TARG, SvCUR(dstr));
@@ -2934,8 +2932,7 @@ Perl_vivify_ref(pTHX_ SV *sv, U32 to_what)
 	if (SvTYPE(sv) < SVt_RV)
 	    sv_upgrade(sv, SVt_RV);
 	else if (SvTYPE(sv) >= SVt_PV) {
-	    SvOOK_off(sv);
-	    Safefree(SvPVX(sv));
+	    SvPV_free(sv);
             SvLEN_set(sv, 0);
 	    SvCUR_set(sv, 0);
 	}
diff --git a/sv.c b/sv.c
index 5353df2ac2..f2e6206729 100644
--- a/sv.c
+++ b/sv.c
@@ -1906,11 +1906,13 @@ Perl_sv_upgrade(pTHX_ register SV *sv, U32 mt)
 	/* to here.  */
 	/* XXX? Only SVt_NULL is ever upgraded to AV or HV?  */
 	assert(!pv);
-	/* FIXME. Should be able to remove this if the above assertion is
-	   genuinely always true.  */
-	(void)SvOOK_off(sv);
-	if (pv)
-	    Safefree(pv);
+	/* FIXME. Should be able to remove all this if()... if the above
+	   assertion is genuinely always true.  */
+	if(SvOOK(sv)) {
+	    pv -= iv;
+	    SvFLAGS(sv) &= ~SVf_OOK;
+	}
+	Safefree(pv);
 	SvPV_set(sv, (char*)0);
 	SvMAGIC_set(sv, magic);
 	SvSTASH_set(sv, stash);
@@ -4416,16 +4418,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
 		return;
 	    }
 	    if (SvPVX(dstr)) {
-		if (SvLEN(dstr)) {
-		    /* Unwrap the OOK offset by hand, to save a needless
-		       memmove on memory that's about to be free()d.  */
-		    char *pv = SvPVX(dstr);
-		    if (SvOOK(dstr)) {
-			pv -= SvIVX(dstr);
-			SvFLAGS(dstr) &= ~SVf_OOK;
-		    }
-		    Safefree(pv);
-		}
+		SvPV_free(dstr);
 		SvLEN_set(dstr, 0);
                 SvCUR_set(dstr, 0);
 	    }
@@ -4843,9 +4836,8 @@ Perl_sv_usepvn(pTHX_ register SV *sv, register char *ptr, register STRLEN len)
 	(void)SvOK_off(sv);
 	return;
     }
-    (void)SvOOK_off(sv);
-    if (SvPVX(sv) && SvLEN(sv))
-	Safefree(SvPVX(sv));
+    if (SvPVX(sv))
+	SvPV_free(sv);
     Renew(ptr, len+1, char);
     SvPV_set(sv, ptr);
     SvCUR_set(sv, len);
@@ -8493,9 +8485,7 @@ Perl_newSVrv(pTHX_ SV *rv, const char *classname)
     if (SvTYPE(rv) < SVt_RV)
 	sv_upgrade(rv, SVt_RV);
     else if (SvTYPE(rv) > SVt_RV) {
-	SvOOK_off(rv);
-	if (SvPVX(rv) && SvLEN(rv))
-	    Safefree(SvPVX(rv));
+	SvPV_free(rv);
 	SvCUR_set(rv, 0);
 	SvLEN_set(rv, 0);
     }
diff --git a/sv.h b/sv.h
index cf71f03430..869cd422b5 100644
--- a/sv.h
+++ b/sv.h
@@ -842,6 +842,18 @@ in gv.h: */
 		   SvPV_renew(sv, _lEnGtH); \
 		 } STMT_END
 
+#define SvPV_free(sv) \
+	STMT_START { assert(SvTYPE(sv) >= SVt_PV);	\
+		if (SvLEN(sv)) {			\
+		    if(SvOOK(sv)) {			\
+		      Safefree(SvPVX(sv) - SvIVX(sv));	\
+		      SvFLAGS(sv) &= ~SVf_OOK;		\
+		    } else {				\
+		      Safefree(SvPVX(sv));		\
+		    }					\
+		}					\
+	} STMT_END
+
 #define BmRARE(sv)	((XPVBM*)  SvANY(sv))->xbm_rare
 #define BmUSEFUL(sv)	((XPVBM*)  SvANY(sv))->xbm_useful
 #define BmPREVIOUS(sv)	((XPVBM*)  SvANY(sv))->xbm_previous