X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/93d7320bf7eac5942274854396d4ccc6268106c7..72de20cdcc84ae35e0d8a55c7a92950fece19347:/pp.c

diff --git a/pp.c b/pp.c
index 112f4f5..98d6482 100644
--- a/pp.c
+++ b/pp.c
@@ -71,11 +71,14 @@ PP(pp_padav)
     if (PL_op->op_flags & OPf_REF) {
 	PUSHs(TARG);
 	RETURN;
-    } else if (LVRET) {
+    } else if (PL_op->op_private & OPpMAYBE_LVSUB) {
+       const I32 flags = is_lvalue_sub();
+       if (flags && !(flags & OPpENTERSUB_INARGS)) {
 	if (GIMME == G_SCALAR)
 	    Perl_croak(aTHX_ "Can't return array to lvalue scalar context");
 	PUSHs(TARG);
 	RETURN;
+       }
     }
     gimme = GIMME_V;
     if (gimme == G_ARRAY) {
@@ -114,14 +117,17 @@ PP(pp_padhv)
 	    SAVECLEARSV(PAD_SVl(PL_op->op_targ));
     if (PL_op->op_flags & OPf_REF)
 	RETURN;
-    else if (LVRET) {
+    else if (PL_op->op_private & OPpMAYBE_LVSUB) {
+      const I32 flags = is_lvalue_sub();
+      if (flags && !(flags & OPpENTERSUB_INARGS)) {
 	if (GIMME == G_SCALAR)
 	    Perl_croak(aTHX_ "Can't return hash to lvalue scalar context");
 	RETURN;
+      }
     }
     gimme = GIMME_V;
     if (gimme == G_ARRAY) {
-	RETURNOP(do_kv());
+	RETURNOP(Perl_do_kv(aTHX));
     }
     else if (gimme == G_SCALAR) {
 	SV* const sv = Perl_hv_scalar(aTHX_ MUTABLE_HV(TARG));
@@ -248,7 +254,10 @@ Perl_softref2xv(pTHX_ SV *const sv, const char *const what,
 	    Perl_die(aTHX_ PL_no_usym, what);
     }
     if (!SvOK(sv)) {
-	if (PL_op->op_flags & OPf_REF)
+	if (
+	  PL_op->op_flags & OPf_REF &&
+	  PL_op->op_next->op_type != OP_BOOLKEYS
+	)
 	    Perl_die(aTHX_ PL_no_usym, what);
 	if (ckWARN(WARN_UNINITIALIZED))
 	    report_uninit(sv);
@@ -698,71 +707,84 @@ PP(pp_study)
 {
     dVAR; dSP; dPOPss;
     register unsigned char *s;
-    register I32 pos;
-    register I32 ch;
-    register I32 *sfirst;
-    register I32 *snext;
+    char *sfirst_raw;
     STRLEN len;
+    MAGIC *mg = SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_study) : NULL;
+    U8 quanta;
+    STRLEN size;
+
+    if (mg && SvSCREAM(sv))
+	RETPUSHYES;
 
-    if (sv == PL_lastscream) {
-	if (SvSCREAM(sv))
-	    RETPUSHYES;
-    }
     s = (unsigned char*)(SvPV(sv, len));
-    pos = len;
-    if (pos <= 0 || !SvPOK(sv) || SvUTF8(sv)) {
+    if (len == 0 || len > I32_MAX || !SvPOK(sv) || SvUTF8(sv) || SvVALID(sv)) {
 	/* No point in studying a zero length string, and not safe to study
 	   anything that doesn't appear to be a simple scalar (and hence might
 	   change between now and when the regexp engine runs without our set
 	   magic ever running) such as a reference to an object with overloaded
-	   stringification.  */
+	   stringification.  Also refuse to study an FBM scalar, as this gives
+	   more flexibility in SV flag usage.  No real-world code would ever
+	   end up studying an FBM scalar, so this isn't a real pessimisation.
+	   Endemic use of I32 in Perl_screaminstr makes it hard to safely push
+	   the study length limit from I32_MAX to U32_MAX - 1.
+	*/
 	RETPUSHNO;
     }
 
-    if (PL_lastscream) {
-	SvSCREAM_off(PL_lastscream);
-	SvREFCNT_dec(PL_lastscream);
-    }
-    PL_lastscream = SvREFCNT_inc_simple(sv);
-
-    s = (unsigned char*)(SvPV(sv, len));
-    pos = len;
-    if (pos <= 0)
-	RETPUSHNO;
-    if (pos > PL_maxscream) {
-	if (PL_maxscream < 0) {
-	    PL_maxscream = pos + 80;
-	    Newx(PL_screamfirst, 256, I32);
-	    Newx(PL_screamnext, PL_maxscream, I32);
-	}
-	else {
-	    PL_maxscream = pos + pos / 4;
-	    Renew(PL_screamnext, PL_maxscream, I32);
-	}
-    }
+    if (len < 0xFF) {
+	quanta = 1;
+    } else if (len < 0xFFFF) {
+	quanta = 2;
+    } else
+	quanta = 4;
 
-    sfirst = PL_screamfirst;
-    snext = PL_screamnext;
+    size = (256 + len) * quanta;
+    sfirst_raw = (char *)safemalloc(size);
 
-    if (!sfirst || !snext)
+    if (!sfirst_raw)
 	DIE(aTHX_ "do_study: out of memory");
 
-    for (ch = 256; ch; --ch)
-	*sfirst++ = -1;
-    sfirst -= 256;
-
-    while (--pos >= 0) {
-	register const I32 ch = s[pos];
-	if (sfirst[ch] >= 0)
-	    snext[pos] = sfirst[ch] - pos;
-	else
-	    snext[pos] = -pos;
-	sfirst[ch] = pos;
+    SvSCREAM_on(sv);
+    if (!mg)
+	mg = sv_magicext(sv, NULL, PERL_MAGIC_study, &PL_vtbl_regexp, NULL, 0);
+    mg->mg_ptr = sfirst_raw;
+    mg->mg_len = size;
+    mg->mg_private = quanta;
+
+    memset(sfirst_raw, ~0, 256 * quanta);
+
+    /* The assumption here is that most studied strings are fairly short, hence
+       the pain of the extra code is worth it, given the memory savings.
+       80 character string, 336 bytes as U8, down from 1344 as U32
+       800 character string, 2112 bytes as U16, down from 4224 as U32
+    */
+       
+    if (quanta == 1) {
+	U8 *const sfirst = (U8 *)sfirst_raw;
+	U8 *const snext = sfirst + 256;
+	while (len-- > 0) {
+	    const U8 ch = s[len];
+	    snext[len] = sfirst[ch];
+	    sfirst[ch] = len;
+	}
+    } else if (quanta == 2) {
+	U16 *const sfirst = (U16 *)sfirst_raw;
+	U16 *const snext = sfirst + 256;
+	while (len-- > 0) {
+	    const U8 ch = s[len];
+	    snext[len] = sfirst[ch];
+	    sfirst[ch] = len;
+	}
+    } else  {
+	U32 *const sfirst = (U32 *)sfirst_raw;
+	U32 *const snext = sfirst + 256;
+	while (len-- > 0) {
+	    const U8 ch = s[len];
+	    snext[len] = sfirst[ch];
+	    sfirst[ch] = len;
+	}
     }
 
-    SvSCREAM_on(sv);
-    /* piggyback on m//g magic */
-    sv_magic(sv, NULL, PERL_MAGIC_regex_global, NULL, 0);
     RETPUSHYES;
 }
 
@@ -791,10 +813,181 @@ PP(pp_trans)
 
 /* Lvalue operators. */
 
+static void
+S_do_chomp(pTHX_ SV *retval, SV *sv, bool chomping)
+{
+    dVAR;
+    STRLEN len;
+    char *s;
+
+    PERL_ARGS_ASSERT_DO_CHOMP;
+
+    if (chomping && (RsSNARF(PL_rs) || RsRECORD(PL_rs)))
+	return;
+    if (SvTYPE(sv) == SVt_PVAV) {
+	I32 i;
+	AV *const av = MUTABLE_AV(sv);
+	const I32 max = AvFILL(av);
+
+	for (i = 0; i <= max; i++) {
+	    sv = MUTABLE_SV(av_fetch(av, i, FALSE));
+	    if (sv && ((sv = *(SV**)sv), sv != &PL_sv_undef))
+		do_chomp(retval, sv, chomping);
+	}
+        return;
+    }
+    else if (SvTYPE(sv) == SVt_PVHV) {
+	HV* const hv = MUTABLE_HV(sv);
+	HE* entry;
+        (void)hv_iterinit(hv);
+        while ((entry = hv_iternext(hv)))
+            do_chomp(retval, hv_iterval(hv,entry), chomping);
+	return;
+    }
+    else if (SvREADONLY(sv)) {
+        if (SvFAKE(sv)) {
+            /* SV is copy-on-write */
+	    sv_force_normal_flags(sv, 0);
+        }
+        if (SvREADONLY(sv))
+            Perl_croak_no_modify(aTHX);
+    }
+
+    if (PL_encoding) {
+	if (!SvUTF8(sv)) {
+	    /* XXX, here sv is utf8-ized as a side-effect!
+	       If encoding.pm is used properly, almost string-generating
+	       operations, including literal strings, chr(), input data, etc.
+	       should have been utf8-ized already, right?
+	    */
+	    sv_recode_to_utf8(sv, PL_encoding);
+	}
+    }
+
+    s = SvPV(sv, len);
+    if (chomping) {
+	char *temp_buffer = NULL;
+	SV *svrecode = NULL;
+
+	if (s && len) {
+	    s += --len;
+	    if (RsPARA(PL_rs)) {
+		if (*s != '\n')
+		    goto nope;
+		++SvIVX(retval);
+		while (len && s[-1] == '\n') {
+		    --len;
+		    --s;
+		    ++SvIVX(retval);
+		}
+	    }
+	    else {
+		STRLEN rslen, rs_charlen;
+		const char *rsptr = SvPV_const(PL_rs, rslen);
+
+		rs_charlen = SvUTF8(PL_rs)
+		    ? sv_len_utf8(PL_rs)
+		    : rslen;
+
+		if (SvUTF8(PL_rs) != SvUTF8(sv)) {
+		    /* Assumption is that rs is shorter than the scalar.  */
+		    if (SvUTF8(PL_rs)) {
+			/* RS is utf8, scalar is 8 bit.  */
+			bool is_utf8 = TRUE;
+			temp_buffer = (char*)bytes_from_utf8((U8*)rsptr,
+							     &rslen, &is_utf8);
+			if (is_utf8) {
+			    /* Cannot downgrade, therefore cannot possibly match
+			     */
+			    assert (temp_buffer == rsptr);
+			    temp_buffer = NULL;
+			    goto nope;
+			}
+			rsptr = temp_buffer;
+		    }
+		    else if (PL_encoding) {
+			/* RS is 8 bit, encoding.pm is used.
+			 * Do not recode PL_rs as a side-effect. */
+			svrecode = newSVpvn(rsptr, rslen);
+			sv_recode_to_utf8(svrecode, PL_encoding);
+			rsptr = SvPV_const(svrecode, rslen);
+			rs_charlen = sv_len_utf8(svrecode);
+		    }
+		    else {
+			/* RS is 8 bit, scalar is utf8.  */
+			temp_buffer = (char*)bytes_to_utf8((U8*)rsptr, &rslen);
+			rsptr = temp_buffer;
+		    }
+		}
+		if (rslen == 1) {
+		    if (*s != *rsptr)
+			goto nope;
+		    ++SvIVX(retval);
+		}
+		else {
+		    if (len < rslen - 1)
+			goto nope;
+		    len -= rslen - 1;
+		    s -= rslen - 1;
+		    if (memNE(s, rsptr, rslen))
+			goto nope;
+		    SvIVX(retval) += rs_charlen;
+		}
+	    }
+	    s = SvPV_force_nolen(sv);
+	    SvCUR_set(sv, len);
+	    *SvEND(sv) = '\0';
+	    SvNIOK_off(sv);
+	    SvSETMAGIC(sv);
+	}
+    nope:
+
+	SvREFCNT_dec(svrecode);
+
+	Safefree(temp_buffer);
+    } else {
+	if (len && !SvPOK(sv))
+	    s = SvPV_force_nomg(sv, len);
+	if (DO_UTF8(sv)) {
+	    if (s && len) {
+		char * const send = s + len;
+		char * const start = s;
+		s = send - 1;
+		while (s > start && UTF8_IS_CONTINUATION(*s))
+		    s--;
+		if (is_utf8_string((U8*)s, send - s)) {
+		    sv_setpvn(retval, s, send - s);
+		    *s = '\0';
+		    SvCUR_set(sv, s - start);
+		    SvNIOK_off(sv);
+		    SvUTF8_on(retval);
+		}
+	    }
+	    else
+		sv_setpvs(retval, "");
+	}
+	else if (s && len) {
+	    s += --len;
+	    sv_setpvn(retval, s, 1);
+	    *s = '\0';
+	    SvCUR_set(sv, len);
+	    SvUTF8_off(sv);
+	    SvNIOK_off(sv);
+	}
+	else
+	    sv_setpvs(retval, "");
+	SvSETMAGIC(sv);
+    }
+}
+
 PP(pp_schop)
 {
     dVAR; dSP; dTARGET;
-    do_chop(TARG, TOPs);
+    const bool chomping = PL_op->op_type == OP_SCHOMP;
+
+    if (chomping)
+	sv_setiv(TARG, 0);
+    do_chomp(TARG, TOPs, chomping);
     SETTARG;
     RETURN;
 }
@@ -802,31 +995,17 @@ PP(pp_schop)
 PP(pp_chop)
 {
     dVAR; dSP; dMARK; dTARGET; dORIGMARK;
+    const bool chomping = PL_op->op_type == OP_CHOMP;
+
+    if (chomping)
+	sv_setiv(TARG, 0);
     while (MARK < SP)
-	do_chop(TARG, *++MARK);
+	do_chomp(TARG, *++MARK, chomping);
     SP = ORIGMARK;
     XPUSHTARG;
     RETURN;
 }
 
-PP(pp_schomp)
-{
-    dVAR; dSP; dTARGET;
-    SETi(do_chomp(TOPs));
-    RETURN;
-}
-
-PP(pp_chomp)
-{
-    dVAR; dSP; dMARK; dTARGET;
-    register I32 count = 0;
-
-    while (SP > MARK)
-	count += do_chomp(POPs);
-    XPUSHi(count);
-    RETURN;
-}
-
 PP(pp_undef)
 {
     dVAR; dSP;
@@ -888,7 +1067,7 @@ PP(pp_undef)
 
 	    gp_free(MUTABLE_GV(sv));
 	    Newxz(gp, 1, GP);
-	    GvGP(sv) = gp_ref(gp);
+	    GvGP_set(sv, gp_ref(gp));
 	    GvSV(sv) = newSV(0);
 	    GvLINE(sv) = CopLINE(PL_curcop);
 	    GvEGV(sv) = MUTABLE_GV(sv);
@@ -1338,7 +1517,7 @@ PP(pp_divide)
                warning before dieing, hence this test goes here.
                If it were immediately before the second SvIV_please, then
                DIE() would be invoked before left was even inspected, so
-               no inpsection would give no warning.  */
+               no inspection would give no warning.  */
             if (right == 0)
                 DIE(aTHX_ "Illegal division by zero");
 
@@ -1838,518 +2017,178 @@ PP(pp_right_shift)
 PP(pp_lt)
 {
     dVAR; dSP;
+    SV *left, *right;
+
     tryAMAGICbin_MG(lt_amg, AMGf_set|AMGf_numeric);
-#ifdef PERL_PRESERVE_IVUV
-    SvIV_please_nomg(TOPs);
-    if (SvIOK(TOPs)) {
-	SvIV_please_nomg(TOPm1s);
-	if (SvIOK(TOPm1s)) {
-	    bool auvok = SvUOK(TOPm1s);
-	    bool buvok = SvUOK(TOPs);
-	
-	    if (!auvok && !buvok) { /* ## IV < IV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		const IV biv = SvIVX(TOPs);
-		
-		SP--;
-		SETs(boolSV(aiv < biv));
-		RETURN;
-	    }
-	    if (auvok && buvok) { /* ## UV < UV ## */
-		const UV auv = SvUVX(TOPm1s);
-		const UV buv = SvUVX(TOPs);
-		
-		SP--;
-		SETs(boolSV(auv < buv));
-		RETURN;
-	    }
-	    if (auvok) { /* ## UV < IV ## */
-		UV auv;
-		const IV biv = SvIVX(TOPs);
-		SP--;
-		if (biv < 0) {
-		    /* As (a) is a UV, it's >=0, so it cannot be < */
-		    SETs(&PL_sv_no);
-		    RETURN;
-		}
-		auv = SvUVX(TOPs);
-		SETs(boolSV(auv < (UV)biv));
-		RETURN;
-	    }
-	    { /* ## IV < UV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		UV buv;
-		
-		if (aiv < 0) {
-		    /* As (b) is a UV, it's >=0, so it must be < */
-		    SP--;
-		    SETs(&PL_sv_yes);
-		    RETURN;
-		}
-		buv = SvUVX(TOPs);
-		SP--;
-		SETs(boolSV((UV)aiv < buv));
-		RETURN;
-	    }
-	}
-    }
-#endif
-#ifndef NV_PRESERVES_UV
-#ifdef PERL_PRESERVE_IVUV
-    else
-#endif
-    if (SvROK(TOPs) && !SvAMAGIC(TOPs) && SvROK(TOPm1s) && !SvAMAGIC(TOPm1s)) {
-	SP--;
-	SETs(boolSV(SvRV(TOPs) < SvRV(TOPp1s)));
-	RETURN;
-    }
-#endif
-    {
-#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
-      dPOPTOPnnrl_nomg;
-      if (Perl_isnan(left) || Perl_isnan(right))
-	  RETSETNO;
-      SETs(boolSV(left < right));
-#else
-      dPOPnv_nomg;
-      SETs(boolSV(SvNV_nomg(TOPs) < value));
-#endif
-      RETURN;
-    }
+    right = POPs;
+    left  = TOPs;
+    SETs(boolSV(
+	(SvIOK_notUV(left) && SvIOK_notUV(right))
+	? (SvIVX(left) < SvIVX(right))
+	: (do_ncmp(left, right) == -1)
+    ));
+    RETURN;
 }
 
 PP(pp_gt)
 {
     dVAR; dSP;
-    tryAMAGICbin_MG(gt_amg, AMGf_set|AMGf_numeric);
-#ifdef PERL_PRESERVE_IVUV
-    SvIV_please_nomg(TOPs);
-    if (SvIOK(TOPs)) {
-	SvIV_please_nomg(TOPm1s);
-	if (SvIOK(TOPm1s)) {
-	    bool auvok = SvUOK(TOPm1s);
-	    bool buvok = SvUOK(TOPs);
-	
-	    if (!auvok && !buvok) { /* ## IV > IV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		const IV biv = SvIVX(TOPs);
+    SV *left, *right;
 
-		SP--;
-		SETs(boolSV(aiv > biv));
-		RETURN;
-	    }
-	    if (auvok && buvok) { /* ## UV > UV ## */
-		const UV auv = SvUVX(TOPm1s);
-		const UV buv = SvUVX(TOPs);
-		
-		SP--;
-		SETs(boolSV(auv > buv));
-		RETURN;
-	    }
-	    if (auvok) { /* ## UV > IV ## */
-		UV auv;
-		const IV biv = SvIVX(TOPs);
-
-		SP--;
-		if (biv < 0) {
-		    /* As (a) is a UV, it's >=0, so it must be > */
-		    SETs(&PL_sv_yes);
-		    RETURN;
-		}
-		auv = SvUVX(TOPs);
-		SETs(boolSV(auv > (UV)biv));
-		RETURN;
-	    }
-	    { /* ## IV > UV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		UV buv;
-		
-		if (aiv < 0) {
-		    /* As (b) is a UV, it's >=0, so it cannot be > */
-		    SP--;
-		    SETs(&PL_sv_no);
-		    RETURN;
-		}
-		buv = SvUVX(TOPs);
-		SP--;
-		SETs(boolSV((UV)aiv > buv));
-		RETURN;
-	    }
-	}
-    }
-#endif
-#ifndef NV_PRESERVES_UV
-#ifdef PERL_PRESERVE_IVUV
-    else
-#endif
-    if (SvROK(TOPs) && !SvAMAGIC(TOPs) && SvROK(TOPm1s) && !SvAMAGIC(TOPm1s)) {
-        SP--;
-        SETs(boolSV(SvRV(TOPs) > SvRV(TOPp1s)));
-        RETURN;
-    }
-#endif
-    {
-#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
-      dPOPTOPnnrl_nomg;
-      if (Perl_isnan(left) || Perl_isnan(right))
-	  RETSETNO;
-      SETs(boolSV(left > right));
-#else
-      dPOPnv_nomg;
-      SETs(boolSV(SvNV_nomg(TOPs) > value));
-#endif
-      RETURN;
-    }
+    tryAMAGICbin_MG(gt_amg, AMGf_set|AMGf_numeric);
+    right = POPs;
+    left  = TOPs;
+    SETs(boolSV(
+	(SvIOK_notUV(left) && SvIOK_notUV(right))
+	? (SvIVX(left) > SvIVX(right))
+	: (do_ncmp(left, right) == 1)
+    ));
+    RETURN;
 }
 
 PP(pp_le)
 {
     dVAR; dSP;
-    tryAMAGICbin_MG(le_amg, AMGf_set|AMGf_numeric);
-#ifdef PERL_PRESERVE_IVUV
-    SvIV_please_nomg(TOPs);
-    if (SvIOK(TOPs)) {
-	SvIV_please_nomg(TOPm1s);
-	if (SvIOK(TOPm1s)) {
-	    bool auvok = SvUOK(TOPm1s);
-	    bool buvok = SvUOK(TOPs);
-	
-	    if (!auvok && !buvok) { /* ## IV <= IV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		const IV biv = SvIVX(TOPs);
-		
-		SP--;
-		SETs(boolSV(aiv <= biv));
-		RETURN;
-	    }
-	    if (auvok && buvok) { /* ## UV <= UV ## */
-		UV auv = SvUVX(TOPm1s);
-		UV buv = SvUVX(TOPs);
-		
-		SP--;
-		SETs(boolSV(auv <= buv));
-		RETURN;
-	    }
-	    if (auvok) { /* ## UV <= IV ## */
-		UV auv;
-		const IV biv = SvIVX(TOPs);
-
-		SP--;
-		if (biv < 0) {
-		    /* As (a) is a UV, it's >=0, so a cannot be <= */
-		    SETs(&PL_sv_no);
-		    RETURN;
-		}
-		auv = SvUVX(TOPs);
-		SETs(boolSV(auv <= (UV)biv));
-		RETURN;
-	    }
-	    { /* ## IV <= UV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		UV buv;
+    SV *left, *right;
 
-		if (aiv < 0) {
-		    /* As (b) is a UV, it's >=0, so a must be <= */
-		    SP--;
-		    SETs(&PL_sv_yes);
-		    RETURN;
-		}
-		buv = SvUVX(TOPs);
-		SP--;
-		SETs(boolSV((UV)aiv <= buv));
-		RETURN;
-	    }
-	}
-    }
-#endif
-#ifndef NV_PRESERVES_UV
-#ifdef PERL_PRESERVE_IVUV
-    else
-#endif
-    if (SvROK(TOPs) && !SvAMAGIC(TOPs) && SvROK(TOPm1s) && !SvAMAGIC(TOPm1s)) {
-        SP--;
-        SETs(boolSV(SvRV(TOPs) <= SvRV(TOPp1s)));
-        RETURN;
-    }
-#endif
-    {
-#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
-      dPOPTOPnnrl_nomg;
-      if (Perl_isnan(left) || Perl_isnan(right))
-	  RETSETNO;
-      SETs(boolSV(left <= right));
-#else
-      dPOPnv_nomg;
-      SETs(boolSV(SvNV_nomg(TOPs) <= value));
-#endif
-      RETURN;
-    }
+    tryAMAGICbin_MG(le_amg, AMGf_set|AMGf_numeric);
+    right = POPs;
+    left  = TOPs;
+    SETs(boolSV(
+	(SvIOK_notUV(left) && SvIOK_notUV(right))
+	? (SvIVX(left) <= SvIVX(right))
+	: (do_ncmp(left, right) <= 0)
+    ));
+    RETURN;
 }
 
 PP(pp_ge)
 {
     dVAR; dSP;
-    tryAMAGICbin_MG(ge_amg,AMGf_set|AMGf_numeric);
-#ifdef PERL_PRESERVE_IVUV
-    SvIV_please_nomg(TOPs);
-    if (SvIOK(TOPs)) {
-	SvIV_please_nomg(TOPm1s);
-	if (SvIOK(TOPm1s)) {
-	    bool auvok = SvUOK(TOPm1s);
-	    bool buvok = SvUOK(TOPs);
-	
-	    if (!auvok && !buvok) { /* ## IV >= IV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		const IV biv = SvIVX(TOPs);
+    SV *left, *right;
+
+    tryAMAGICbin_MG(ge_amg, AMGf_set|AMGf_numeric);
+    right = POPs;
+    left  = TOPs;
+    SETs(boolSV(
+	(SvIOK_notUV(left) && SvIOK_notUV(right))
+	? (SvIVX(left) >= SvIVX(right))
+	: ( (do_ncmp(left, right) & 2) == 0)
+    ));
+    RETURN;
+}
 
-		SP--;
-		SETs(boolSV(aiv >= biv));
-		RETURN;
-	    }
-	    if (auvok && buvok) { /* ## UV >= UV ## */
-		const UV auv = SvUVX(TOPm1s);
-		const UV buv = SvUVX(TOPs);
+PP(pp_ne)
+{
+    dVAR; dSP;
+    SV *left, *right;
+
+    tryAMAGICbin_MG(ne_amg, AMGf_set|AMGf_numeric);
+    right = POPs;
+    left  = TOPs;
+    SETs(boolSV(
+	(SvIOK_notUV(left) && SvIOK_notUV(right))
+	? (SvIVX(left) != SvIVX(right))
+	: (do_ncmp(left, right) != 0)
+    ));
+    RETURN;
+}
 
-		SP--;
-		SETs(boolSV(auv >= buv));
-		RETURN;
-	    }
-	    if (auvok) { /* ## UV >= IV ## */
-		UV auv;
-		const IV biv = SvIVX(TOPs);
+/* compare left and right SVs. Returns:
+ * -1: <
+ *  0: ==
+ *  1: >
+ *  2: left or right was a NaN
+ */
+I32
+Perl_do_ncmp(pTHX_ SV* const left, SV * const right)
+{
+    dVAR;
 
-		SP--;
-		if (biv < 0) {
-		    /* As (a) is a UV, it's >=0, so it must be >= */
-		    SETs(&PL_sv_yes);
-		    RETURN;
+    PERL_ARGS_ASSERT_DO_NCMP;
+#ifdef PERL_PRESERVE_IVUV
+    SvIV_please_nomg(right);
+    /* Fortunately it seems NaN isn't IOK */
+    if (SvIOK(right)) {
+	SvIV_please_nomg(left);
+	if (SvIOK(left)) {
+	    if (!SvUOK(left)) {
+		const IV leftiv = SvIVX(left);
+		if (!SvUOK(right)) {
+		    /* ## IV <=> IV ## */
+		    const IV rightiv = SvIVX(right);
+		    return (leftiv > rightiv) - (leftiv < rightiv);
 		}
-		auv = SvUVX(TOPs);
-		SETs(boolSV(auv >= (UV)biv));
-		RETURN;
-	    }
-	    { /* ## IV >= UV ## */
-		const IV aiv = SvIVX(TOPm1s);
-		UV buv;
-
-		if (aiv < 0) {
-		    /* As (b) is a UV, it's >=0, so a cannot be >= */
-		    SP--;
-		    SETs(&PL_sv_no);
-		    RETURN;
+		/* ## IV <=> UV ## */
+		if (leftiv < 0)
+		    /* As (b) is a UV, it's >=0, so it must be < */
+		    return -1;
+		{
+		    const UV rightuv = SvUVX(right);
+		    return ((UV)leftiv > rightuv) - ((UV)leftiv < rightuv);
 		}
-		buv = SvUVX(TOPs);
-		SP--;
-		SETs(boolSV((UV)aiv >= buv));
-		RETURN;
 	    }
-	}
-    }
-#endif
-#ifndef NV_PRESERVES_UV
-#ifdef PERL_PRESERVE_IVUV
-    else
-#endif
-    if (SvROK(TOPs) && !SvAMAGIC(TOPs) && SvROK(TOPm1s) && !SvAMAGIC(TOPm1s)) {
-        SP--;
-        SETs(boolSV(SvRV(TOPs) >= SvRV(TOPp1s)));
-        RETURN;
-    }
-#endif
-    {
-#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
-      dPOPTOPnnrl_nomg;
-      if (Perl_isnan(left) || Perl_isnan(right))
-	  RETSETNO;
-      SETs(boolSV(left >= right));
-#else
-      dPOPnv_nomg;
-      SETs(boolSV(SvNV_nomg(TOPs) >= value));
-#endif
-      RETURN;
-    }
-}
 
-PP(pp_ne)
-{
-    dVAR; dSP;
-    tryAMAGICbin_MG(ne_amg,AMGf_set|AMGf_numeric);
-#ifndef NV_PRESERVES_UV
-    if (SvROK(TOPs) && !SvAMAGIC(TOPs) && SvROK(TOPm1s) && !SvAMAGIC(TOPm1s)) {
-        SP--;
-	SETs(boolSV(SvRV(TOPs) != SvRV(TOPp1s)));
-	RETURN;
-    }
-#endif
-#ifdef PERL_PRESERVE_IVUV
-    SvIV_please_nomg(TOPs);
-    if (SvIOK(TOPs)) {
-	SvIV_please_nomg(TOPm1s);
-	if (SvIOK(TOPm1s)) {
-	    const bool auvok = SvUOK(TOPm1s);
-	    const bool buvok = SvUOK(TOPs);
-	
-	    if (auvok == buvok) { /* ## IV == IV or UV == UV ## */
-                /* Casting IV to UV before comparison isn't going to matter
-                   on 2s complement. On 1s complement or sign&magnitude
-                   (if we have any of them) it could make negative zero
-                   differ from normal zero. As I understand it. (Need to
-                   check - is negative zero implementation defined behaviour
-                   anyway?). NWC  */
-		const UV buv = SvUVX(POPs);
-		const UV auv = SvUVX(TOPs);
-
-		SETs(boolSV(auv != buv));
-		RETURN;
+	    if (SvUOK(right)) {
+		/* ## UV <=> UV ## */
+		const UV leftuv = SvUVX(left);
+		const UV rightuv = SvUVX(right);
+		return (leftuv > rightuv) - (leftuv < rightuv);
 	    }
-	    {			/* ## Mixed IV,UV ## */
-		IV iv;
-		UV uv;
-		
-		/* != is commutative so swap if needed (save code) */
-		if (auvok) {
-		    /* swap. top of stack (b) is the iv */
-		    iv = SvIVX(TOPs);
-		    SP--;
-		    if (iv < 0) {
-			/* As (a) is a UV, it's >0, so it cannot be == */
-			SETs(&PL_sv_yes);
-			RETURN;
-		    }
-		    uv = SvUVX(TOPs);
-		} else {
-		    iv = SvIVX(TOPm1s);
-		    SP--;
-		    if (iv < 0) {
-			/* As (b) is a UV, it's >0, so it cannot be == */
-			SETs(&PL_sv_yes);
-			RETURN;
-		    }
-		    uv = SvUVX(*(SP+1)); /* Do I want TOPp1s() ? */
+	    /* ## UV <=> IV ## */
+	    {
+		const IV rightiv = SvIVX(right);
+		if (rightiv < 0)
+		    /* As (a) is a UV, it's >=0, so it cannot be < */
+		    return 1;
+		{
+		    const UV leftuv = SvUVX(left);
+		    return (leftuv > (UV)rightiv) - (leftuv < (UV)rightiv);
 		}
-		SETs(boolSV((UV)iv != uv));
-		RETURN;
 	    }
+	    /* NOTREACHED */
 	}
     }
 #endif
     {
+      NV const rnv = SvNV_nomg(right);
+      NV const lnv = SvNV_nomg(left);
+
 #if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
-      dPOPTOPnnrl_nomg;
-      if (Perl_isnan(left) || Perl_isnan(right))
-	  RETSETYES;
-      SETs(boolSV(left != right));
+      if (Perl_isnan(lnv) || Perl_isnan(rnv)) {
+	  return 2;
+       }
+      return (lnv > rnv) - (lnv < rnv);
 #else
-      dPOPnv_nomg;
-      SETs(boolSV(SvNV_nomg(TOPs) != value));
+      if (lnv < rnv)
+	return -1;
+      if (lnv > rnv)
+	return 1;
+      if (lnv == rnv)
+	return 0;
+      return 2;
 #endif
-      RETURN;
     }
 }
 
+
 PP(pp_ncmp)
 {
-    dVAR; dSP; dTARGET;
+    dVAR; dSP;
+    SV *left, *right;
+    I32 value;
     tryAMAGICbin_MG(ncmp_amg, AMGf_numeric);
-#ifndef NV_PRESERVES_UV
-    if (SvROK(TOPs) && !SvAMAGIC(TOPs) && SvROK(TOPm1s) && !SvAMAGIC(TOPm1s)) {
-	const UV right = PTR2UV(SvRV(POPs));
-	const UV left = PTR2UV(SvRV(TOPs));
-	SETi((left > right) - (left < right));
-	RETURN;
-    }
-#endif
-#ifdef PERL_PRESERVE_IVUV
-    /* Fortunately it seems NaN isn't IOK */
-    SvIV_please_nomg(TOPs);
-    if (SvIOK(TOPs)) {
-	SvIV_please_nomg(TOPm1s);
-	if (SvIOK(TOPm1s)) {
-	    const bool leftuvok = SvUOK(TOPm1s);
-	    const bool rightuvok = SvUOK(TOPs);
-	    I32 value;
-	    if (!leftuvok && !rightuvok) { /* ## IV <=> IV ## */
-		const IV leftiv = SvIVX(TOPm1s);
-		const IV rightiv = SvIVX(TOPs);
-		
-		if (leftiv > rightiv)
-		    value = 1;
-		else if (leftiv < rightiv)
-		    value = -1;
-		else
-		    value = 0;
-	    } else if (leftuvok && rightuvok) { /* ## UV <=> UV ## */
-		const UV leftuv = SvUVX(TOPm1s);
-		const UV rightuv = SvUVX(TOPs);
-		
-		if (leftuv > rightuv)
-		    value = 1;
-		else if (leftuv < rightuv)
-		    value = -1;
-		else
-		    value = 0;
-	    } else if (leftuvok) { /* ## UV <=> IV ## */
-		const IV rightiv = SvIVX(TOPs);
-		if (rightiv < 0) {
-		    /* As (a) is a UV, it's >=0, so it cannot be < */
-		    value = 1;
-		} else {
-		    const UV leftuv = SvUVX(TOPm1s);
-		    if (leftuv > (UV)rightiv) {
-			value = 1;
-		    } else if (leftuv < (UV)rightiv) {
-			value = -1;
-		    } else {
-			value = 0;
-		    }
-		}
-	    } else { /* ## IV <=> UV ## */
-		const IV leftiv = SvIVX(TOPm1s);
-		if (leftiv < 0) {
-		    /* As (b) is a UV, it's >=0, so it must be < */
-		    value = -1;
-		} else {
-		    const UV rightuv = SvUVX(TOPs);
-		    if ((UV)leftiv > rightuv) {
-			value = 1;
-		    } else if ((UV)leftiv < rightuv) {
-			value = -1;
-		    } else {
-			value = 0;
-		    }
-		}
-	    }
-	    SP--;
-	    SETi(value);
-	    RETURN;
-	}
-    }
-#endif
-    {
-      dPOPTOPnnrl_nomg;
-      I32 value;
-
-#ifdef Perl_isnan
-      if (Perl_isnan(left) || Perl_isnan(right)) {
-	  SETs(&PL_sv_undef);
-	  RETURN;
-       }
-      value = (left > right) - (left < right);
-#else
-      if (left == right)
-	value = 0;
-      else if (left < right)
-	value = -1;
-      else if (left > right)
-	value = 1;
-      else {
+    right = POPs;
+    left  = TOPs;
+    value = do_ncmp(left, right);
+    if (value == 2) {
 	SETs(&PL_sv_undef);
-	RETURN;
-      }
-#endif
-      SETi(value);
-      RETURN;
     }
+    else {
+	dTARGET;
+	SETi(value);
+    }
+    RETURN;
 }
 
 PP(pp_sle)
@@ -3170,8 +3009,11 @@ PP(pp_length)
 			   SV_UNDEF_RETURNS_NULL|SV_CONST_RETURN|SV_GMAGIC);
 
 	if (!p) {
-	    sv_setsv(TARG, &PL_sv_undef);
-	    SETTARG;
+	    if (!SvPADTMP(TARG)) {
+		sv_setsv(TARG, &PL_sv_undef);
+		SETTARG;
+	    }
+	    SETs(&PL_sv_undef);
 	}
 	else if (DO_UTF8(sv)) {
 	    SETi(utf8_length((U8*)p, (U8*)p + len));
@@ -3185,8 +3027,11 @@ PP(pp_length)
 	else
 	    SETi(sv_len(sv));
     } else {
-	sv_setsv_nomg(TARG, &PL_sv_undef);
-	SETTARG;
+	if (!SvPADTMP(TARG)) {
+	    sv_setsv_nomg(TARG, &PL_sv_undef);
+	    SETTARG;
+	}
+	SETs(&PL_sv_undef);
     }
     RETURN;
 }
@@ -3380,7 +3225,8 @@ PP(pp_substr)
 	}
     }
     SPAGAIN;
-    PUSHs(TARG);		/* avoid SvSETMAGIC here */
+    SvSETMAGIC(TARG);
+    PUSHs(TARG);
     RETURN;
 
 bound_fail:
@@ -3541,8 +3387,6 @@ PP(pp_index)
 PP(pp_sprintf)
 {
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    if (SvTAINTED(MARK[1]))
-	TAINT_PROPER("sprintf");
     SvTAINTED_off(TARG);
     do_sprintf(TARG, SP-MARK, MARK+1);
     TAINT_IF(SvTAINTED(TARG));
@@ -3681,12 +3525,6 @@ PP(pp_crypt)
 /* Generally UTF-8 and UTF-EBCDIC are indistinguishable at this level.  So 
  * most comments below say UTF-8, when in fact they mean UTF-EBCDIC as well */
 
-/* Both the characters below can be stored in two UTF-8 bytes.  In UTF-8 the max
- * character that 2 bytes can hold is U+07FF, and in UTF-EBCDIC it is U+03FF.
- * See http://www.unicode.org/unicode/reports/tr16 */
-#define LATIN_CAPITAL_LETTER_Y_WITH_DIAERESIS 0x0178	/* Also is title case */
-#define GREEK_CAPITAL_LETTER_MU 0x039C	/* Upper and title case of MICRON */
-
 /* Below are several macros that generate code */
 /* Generates code to store a unicode codepoint c that is known to occupy
  * exactly two UTF-8 and UTF-EBCDIC bytes; it is stored into p and p+1. */
@@ -4050,6 +3888,8 @@ PP(pp_ucfirst)
 	    SvCUR_set(dest, need - 1);
 	}
     }
+    if (dest != source && SvTAINTED(source))
+	SvTAINT(dest);
     SvSETMAGIC(dest);
     RETURN;
 }
@@ -4320,6 +4160,8 @@ PP(pp_uc)
 	    SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
 	}
     } /* End of isn't utf8 */
+    if (dest != source && SvTAINTED(source))
+	SvTAINT(dest);
     SvSETMAGIC(dest);
     RETURN;
 }
@@ -4542,6 +4384,8 @@ PP(pp_lc)
 	    SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
 	}
     }
+    if (dest != source && SvTAINTED(source))
+	SvTAINT(dest);
     SvSETMAGIC(dest);
     RETURN;
 }
@@ -4671,54 +4515,26 @@ PP(pp_rkeys)
     dSP;
     dPOPss;
 
-    if (!SvOK(sv))
-	RETURN;
-
-    if (SvROK(sv)) {
-	SvGETMAGIC(sv);
-	if (SvAMAGIC(sv)) {
-	    /* N.B.: AMG macros return sv if no overloading is found */
-	    SV *maybe_hv = AMG_CALLun(sv,to_hv);
-	    SV *maybe_av = AMG_CALLun(sv,to_av);
-	    if ( maybe_hv != sv && maybe_av != sv ) {
-		Perl_ck_warner(aTHX_ packWARN(WARN_AMBIGUOUS), "%s",
-		    Perl_form(aTHX_ "Ambiguous overloaded argument to %s resolved as %%{}",
-			PL_op_desc[PL_op->op_type]
-		    )
-		);
-		sv = maybe_hv;
-	    }
-	    else if ( maybe_av != sv ) {
-		if ( SvTYPE(SvRV(sv)) == SVt_PVHV ) {
-		    /* @{} overload, but underlying reftype is HV */
-		    Perl_ck_warner(aTHX_ packWARN(WARN_AMBIGUOUS), "%s",
-			Perl_form(aTHX_ "Ambiguous overloaded argument to %s resolved as @{}",
-			    PL_op_desc[PL_op->op_type]
-			)
-		    );
-		}
-		sv = maybe_av;
-	    }
-	    else if ( maybe_hv != sv ) {
-		if ( SvTYPE(SvRV(sv)) == SVt_PVAV ) {
-		    /* %{} overload, but underlying reftype is AV */
-		    Perl_ck_warner(aTHX_ packWARN(WARN_AMBIGUOUS), "%s",
-			Perl_form(aTHX_ "Ambiguous overloaded argument to %s resolved as %%{}",
-			    PL_op_desc[PL_op->op_type]
-			)
-		    );
-		}
-		sv = maybe_hv;
-	    }
-	}
-	sv = SvRV(sv);
-    }
-
-    if ( SvTYPE(sv) != SVt_PVHV && SvTYPE(sv) != SVt_PVAV ) {
-	DIE(aTHX_ "Type of argument to %s must be hashref or arrayref",
+    SvGETMAGIC(sv);
+
+    if (
+         !SvROK(sv)
+      || (sv = SvRV(sv),
+            (SvTYPE(sv) != SVt_PVHV && SvTYPE(sv) != SVt_PVAV)
+          || SvOBJECT(sv)
+         )
+    ) {
+	DIE(aTHX_
+	   "Type of argument to %s must be unblessed hashref or arrayref",
 	    PL_op_desc[PL_op->op_type] );
     }
 
+    if (PL_op->op_flags & OPf_SPECIAL && SvTYPE(sv) == SVt_PVAV)
+	DIE(aTHX_
+	   "Can't modify %s in %s",
+	    PL_op_desc[PL_op->op_type], PL_op_desc[PL_op->op_next->op_type]
+	);
+
     /* Delegate to correct function for op type */
     PUSHs(sv);
     if (PL_op->op_type == OP_RKEYS || PL_op->op_type == OP_RVALUES) {
@@ -5259,10 +5075,41 @@ PP(pp_anonhash)
     RETURN;
 }
 
+static AV *
+S_deref_plain_array(pTHX_ AV *ary)
+{
+    if (SvTYPE(ary) == SVt_PVAV) return ary;
+    SvGETMAGIC((SV *)ary);
+    if (!SvROK(ary) || SvTYPE(SvRV(ary)) != SVt_PVAV)
+	Perl_die(aTHX_ "Not an ARRAY reference");
+    else if (SvOBJECT(SvRV(ary)))
+	Perl_die(aTHX_ "Not an unblessed ARRAY reference");
+    return (AV *)SvRV(ary);
+}
+
+#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
+# define DEREF_PLAIN_ARRAY(ary)       \
+   ({                                  \
+     AV *aRrRay = ary;                  \
+     SvTYPE(aRrRay) == SVt_PVAV          \
+      ? aRrRay                            \
+      : S_deref_plain_array(aTHX_ aRrRay); \
+   })
+#else
+# define DEREF_PLAIN_ARRAY(ary)            \
+   (                                        \
+     PL_Sv = (SV *)(ary),                    \
+     SvTYPE(PL_Sv) == SVt_PVAV                \
+      ? (AV *)PL_Sv                            \
+      : S_deref_plain_array(aTHX_ (AV *)PL_Sv)  \
+   )
+#endif
+
 PP(pp_splice)
 {
     dVAR; dSP; dMARK; dORIGMARK;
-    register AV *ary = MUTABLE_AV(*++MARK);
+    int num_args = (SP - MARK);
+    register AV *ary = DEREF_PLAIN_ARRAY(MUTABLE_AV(*++MARK));
     register SV **src;
     register SV **dst;
     register I32 i;
@@ -5274,14 +5121,9 @@ PP(pp_splice)
     const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);
 
     if (mg) {
-	*MARK-- = SvTIED_obj(MUTABLE_SV(ary), mg);
-	PUSHMARK(MARK);
-	PUTBACK;
-	ENTER_with_name("call_SPLICE");
-	call_method("SPLICE",GIMME_V);
-	LEAVE_with_name("call_SPLICE");
-	SPAGAIN;
-	RETURN;
+	return Perl_tied_method(aTHX_ "SPLICE", mark - 1, MUTABLE_SV(ary), mg,
+				    GIMME_V | TIED_METHOD_ARGUMENTS_ON_STACK,
+				    sp - mark);
     }
 
     SP++;
@@ -5310,7 +5152,8 @@ PP(pp_splice)
 	length = AvMAX(ary) + 1;
     }
     if (offset > AvFILLp(ary) + 1) {
-	Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
+	if (num_args > 2)
+	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
 	offset = AvFILLp(ary) + 1;
     }
     after = AvFILLp(ary) + 1 - (offset + length);
@@ -5348,7 +5191,7 @@ PP(pp_splice)
 	    if (AvREAL(ary)) {
 		EXTEND_MORTAL(length);
 		for (i = length, dst = MARK; i; i--) {
-		    sv_2mortal(*dst);	/* free them eventualy */
+		    sv_2mortal(*dst);	/* free them eventually */
 		    dst++;
 		}
 	    }
@@ -5440,7 +5283,7 @@ PP(pp_splice)
 		if (AvREAL(ary)) {
 		    EXTEND_MORTAL(length);
 		    for (i = length, dst = MARK; i; i--) {
-			sv_2mortal(*dst);	/* free them eventualy */
+			sv_2mortal(*dst);	/* free them eventually */
 			dst++;
 		    }
 		}
@@ -5470,7 +5313,7 @@ PP(pp_splice)
 PP(pp_push)
 {
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    register AV * const ary = MUTABLE_AV(*++MARK);
+    register AV * const ary = DEREF_PLAIN_ARRAY(MUTABLE_AV(*++MARK));
     const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);
 
     if (mg) {
@@ -5507,7 +5350,7 @@ PP(pp_shift)
     dVAR;
     dSP;
     AV * const av = PL_op->op_flags & OPf_SPECIAL
-	? MUTABLE_AV(GvAV(PL_defgv)) : MUTABLE_AV(POPs);
+	? MUTABLE_AV(GvAV(PL_defgv)) : DEREF_PLAIN_ARRAY(MUTABLE_AV(POPs));
     SV * const sv = PL_op->op_type == OP_SHIFT ? av_shift(av) : av_pop(av);
     EXTEND(SP, 1);
     assert (sv);
@@ -5520,7 +5363,7 @@ PP(pp_shift)
 PP(pp_unshift)
 {
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    register AV *ary = MUTABLE_AV(*++MARK);
+    register AV *ary = DEREF_PLAIN_ARRAY(MUTABLE_AV(*++MARK));
     const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);
 
     if (mg) {
@@ -5718,7 +5561,7 @@ PP(pp_split)
 	DIE(aTHX_ "panic: pp_split");
     rx = PM_GETRE(pm);
 
-    TAINT_IF((RX_EXTFLAGS(rx) & RXf_PMf_LOCALE) &&
+    TAINT_IF(get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET &&
 	     (RX_EXTFLAGS(rx) & (RXf_WHITE | RXf_SKIPWHITE)));
 
     RX_MATCH_UTF8_set(rx, do_utf8);
@@ -5764,7 +5607,7 @@ PP(pp_split)
 	    while (*s == ' ' || is_utf8_space((U8*)s))
 		s += UTF8SKIP(s);
 	}
-	else if (RX_EXTFLAGS(rx) & RXf_PMf_LOCALE) {
+	else if (get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET) {
 	    while (isSPACE_LC(*s))
 		s++;
 	}
@@ -5773,7 +5616,7 @@ PP(pp_split)
 		s++;
 	}
     }
-    if (RX_EXTFLAGS(rx) & PMf_MULTILINE) {
+    if (RX_EXTFLAGS(rx) & RXf_PMf_MULTILINE) {
 	multiline = 1;
     }
 
@@ -5794,7 +5637,8 @@ PP(pp_split)
 		    else
 			m += t;
 		}
-            } else if (RX_EXTFLAGS(rx) & RXf_PMf_LOCALE) {
+	    }
+	    else if (get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET) {
 	        while (m < strend && !isSPACE_LC(*m))
 		    ++m;
             } else {
@@ -5826,7 +5670,8 @@ PP(pp_split)
 	    if (do_utf8) {
 		while (s < strend && ( *s == ' ' || is_utf8_space((U8*)s) ))
 	            s +=  UTF8SKIP(s);
-            } else if (RX_EXTFLAGS(rx) & RXf_PMf_LOCALE) {
+	    }
+	    else if (get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET) {
 	        while (s < strend && isSPACE_LC(*s))
 		    ++s;
             } else {
@@ -5981,7 +5826,7 @@ PP(pp_split)
 	    I32 rex_return;
 	    PUTBACK;
 	    rex_return = CALLREGEXEC(rx, (char*)s, (char*)strend, (char*)orig, 1 ,
-			    sv, NULL, 0);
+				     sv, NULL, SvSCREAM(sv) ? REXEC_SCREAM : 0);
 	    SPAGAIN;
 	    if (rex_return == 0)
 		break;
@@ -6143,8 +5988,20 @@ PP(pp_lock)
 PP(unimplemented_op)
 {
     dVAR;
-    DIE(aTHX_ "panic: unimplemented op %s (#%d) called", OP_NAME(PL_op),
-	PL_op->op_type);
+    const Optype op_type = PL_op->op_type;
+    /* Using OP_NAME() isn't going to be helpful here. Firstly, it doesn't cope
+       with out of range op numbers - it only "special" cases op_custom.
+       Secondly, as the three ops we "panic" on are padmy, mapstart and custom,
+       if we get here for a custom op then that means that the custom op didn't
+       have an implementation. Given that OP_NAME() looks up the custom op
+       by its pp_addr, likely it will return NULL, unless someone (unhelpfully)
+       registers &PL_unimplemented_op as the address of their custom op.
+       NULL doesn't generate a useful error message. "custom" does. */
+    const char *const name = op_type >= OP_max
+	? "[out of range]" : PL_op_name[PL_op->op_type];
+    if(OP_IS_SOCKET(op_type))
+	DIE(aTHX_ PL_no_sock_func, name);
+    DIE(aTHX_ "panic: unimplemented op %s (#%d) called", name,	op_type);
 }
 
 PP(pp_boolkeys)
@@ -6153,6 +6010,8 @@ PP(pp_boolkeys)
     dSP;
     HV * const hv = (HV*)POPs;
     
+    if (SvTYPE(hv) != SVt_PVHV) { XPUSHs(&PL_sv_no); RETURN; }
+
     if (SvRMAGICAL(hv)) {
 	MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
 	if (mg) {
@@ -6161,7 +6020,7 @@ PP(pp_boolkeys)
         }	    
     }
 
-    XPUSHs(boolSV(HvKEYS(hv) != 0));
+    XPUSHs(boolSV(HvUSEDKEYS(hv) != 0));
     RETURN;
 }