This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Correct INSTALL to warn about editing cflags, not cflags.SH
[perl5.git] / regcomp.c
index d2085fc..b106cc1 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -86,6 +86,9 @@
 #endif
 
 #include "dquote_static.c"
+#ifndef PERL_IN_XSUB_RE
+#  include "charclass_invlists.h"
+#endif
 
 #ifdef op
 #undef op
@@ -379,9 +382,11 @@ static const scan_data_t zero_scan_data =
 #define SCF_SEEN_ACCEPT         0x8000 
 
 #define UTF cBOOL(RExC_utf8)
+
+/* The enums for all these are ordered so things work out correctly */
 #define LOC (get_regex_charset(RExC_flags) == REGEX_LOCALE_CHARSET)
-#define UNI_SEMANTICS (get_regex_charset(RExC_flags) == REGEX_UNICODE_CHARSET)
 #define DEPENDS_SEMANTICS (get_regex_charset(RExC_flags) == REGEX_DEPENDS_CHARSET)
+#define UNI_SEMANTICS (get_regex_charset(RExC_flags) == REGEX_UNICODE_CHARSET)
 #define AT_LEAST_UNI_SEMANTICS (get_regex_charset(RExC_flags) >= REGEX_UNICODE_CHARSET)
 #define ASCII_RESTRICTED (get_regex_charset(RExC_flags) == REGEX_ASCII_RESTRICTED_CHARSET)
 #define MORE_ASCII_RESTRICTED (get_regex_charset(RExC_flags) == REGEX_ASCII_MORE_RESTRICTED_CHARSET)
@@ -1361,44 +1366,47 @@ is the recommended Unicode-aware way of saying
     *(d++) = uv;
 */
 
-#define TRIE_STORE_REVCHAR                                                 \
+#define TRIE_STORE_REVCHAR(val)                                            \
     STMT_START {                                                           \
        if (UTF) {                                                         \
-           SV *zlopp = newSV(2);                                          \
+            SV *zlopp = newSV(7); /* XXX: optimize me */                   \
            unsigned char *flrbbbbb = (unsigned char *) SvPVX(zlopp);      \
-           unsigned const char *const kapow = uvuni_to_utf8(flrbbbbb, uvc & 0xFF); \
+            unsigned const char *const kapow = uvuni_to_utf8(flrbbbbb, val); \
            SvCUR_set(zlopp, kapow - flrbbbbb);                            \
            SvPOK_on(zlopp);                                               \
            SvUTF8_on(zlopp);                                              \
            av_push(revcharmap, zlopp);                                    \
        } else {                                                           \
-           char ooooff = (char)uvc;                                               \
+            char ooooff = (char)val;                                           \
            av_push(revcharmap, newSVpvn(&ooooff, 1));                     \
        }                                                                  \
         } STMT_END
 
-#define TRIE_READ_CHAR STMT_START {                                           \
-    wordlen++;                                                                \
-    if ( UTF ) {                                                              \
-       if ( folder ) {                                                       \
-           if ( foldlen > 0 ) {                                              \
-              uvc = utf8n_to_uvuni( scan, UTF8_MAXLEN, &len, uniflags );     \
-              foldlen -= len;                                                \
-              scan += len;                                                   \
-              len = 0;                                                       \
-           } else {                                                          \
-               len = UTF8SKIP(uc);\
-               uvc = to_utf8_fold( uc, foldbuf, &foldlen);                   \
-               foldlen -= UNISKIP( uvc );                                    \
-               scan = foldbuf + UNISKIP( uvc );                              \
-           }                                                                 \
-       } else {                                                              \
-           uvc = utf8n_to_uvuni( (const U8*)uc, UTF8_MAXLEN, &len, uniflags);\
-       }                                                                     \
-    } else {                                                                  \
-       uvc = (U32)*uc;                                                       \
-       len = 1;                                                              \
-    }                                                                         \
+#define TRIE_READ_CHAR STMT_START {                                                     \
+    wordlen++;                                                                          \
+    if ( UTF ) {                                                                        \
+        /* if it is UTF then it is either already folded, or does not need folding */   \
+        uvc = utf8n_to_uvuni( (const U8*) uc, UTF8_MAXLEN, &len, uniflags);             \
+    }                                                                                   \
+    else if (folder == PL_fold_latin1) {                                                \
+        /* if we use this folder we have to obey unicode rules on latin-1 data */       \
+        if ( foldlen > 0 ) {                                                            \
+           uvc = utf8n_to_uvuni( (const U8*) scan, UTF8_MAXLEN, &len, uniflags );       \
+           foldlen -= len;                                                              \
+           scan += len;                                                                 \
+           len = 0;                                                                     \
+        } else {                                                                        \
+            len = 1;                                                                    \
+            uvc = _to_fold_latin1( (U8) *uc, foldbuf, &foldlen, 1);                     \
+            skiplen = UNISKIP(uvc);                                                     \
+            foldlen -= skiplen;                                                         \
+            scan = foldbuf + skiplen;                                                   \
+        }                                                                               \
+    } else {                                                                            \
+        /* raw data, will be folded later if needed */                                  \
+        uvc = (U32)*uc;                                                                 \
+        len = 1;                                                                        \
+    }                                                                                   \
 } STMT_END
 
 
@@ -1517,10 +1525,12 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     switch (flags) {
        case EXACT: break;
        case EXACTFA:
+        case EXACTFU_SS:
+        case EXACTFU_TRICKYFOLD:
        case EXACTFU: folder = PL_fold_latin1; break;
        case EXACTF:  folder = PL_fold; break;
        case EXACTFL: folder = PL_fold_locale; break;
-        default: Perl_croak( aTHX_ "panic! In trie construction, unknown node type %u", (unsigned) flags );
+        default: Perl_croak( aTHX_ "panic! In trie construction, unknown node type %u %s", (unsigned) flags, PL_reg_name[flags] );
     }
 
     trie = (reg_trie_data *) PerlMemShared_calloc( 1, sizeof(reg_trie_data) );
@@ -1529,7 +1539,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     trie->wordcount = word_count;
     RExC_rxi->data->data[ data_slot ] = (void*)trie;
     trie->charmap = (U16 *) PerlMemShared_calloc( 256, sizeof(U16) );
-    if (!(UTF && folder))
+    if (flags == EXACT)
        trie->bitmap = (char *) PerlMemShared_calloc( ANYOF_BITMAP_SIZE, 1 );
     trie->wordinfo = (reg_trie_wordinfo *) PerlMemShared_calloc(
                        trie->wordcount+1, sizeof(reg_trie_wordinfo));
@@ -1589,6 +1599,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
         const U8 * const e  = uc + STR_LEN( noper );
         STRLEN foldlen = 0;
         U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
+        STRLEN skiplen = 0;
         const U8 *scan = (U8*)NULL;
         U32 wordlen      = 0;         /* required init */
         STRLEN chars = 0;
@@ -1598,28 +1609,37 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
             trie->minlen= 0;
             continue;
         }
-        if ( set_bit ) /* bitmap only alloced when !(UTF&&Folding) */
+        if ( set_bit ) /* bitmap only alloced when !(UTF&&Folding) */
             TRIE_BITMAP_SET(trie,*uc); /* store the raw first byte
                                           regardless of encoding */
-
+            if (OP( noper ) == EXACTFU_SS) {
+                /* false positives are ok, so just set this */
+                TRIE_BITMAP_SET(trie,0xDF);
+            }
+        }
         for ( ; uc < e ; uc += len ) {
             TRIE_CHARCOUNT(trie)++;
             TRIE_READ_CHAR;
             chars++;
             if ( uvc < 256 ) {
+                if ( folder ) {
+                    U8 folded= folder[ (U8) uvc ];
+                    if ( !trie->charmap[ folded ] ) {
+                        trie->charmap[ folded ]=( ++trie->uniquecharcount );
+                        TRIE_STORE_REVCHAR( folded );
+                    }
+                }
                 if ( !trie->charmap[ uvc ] ) {
                     trie->charmap[ uvc ]=( ++trie->uniquecharcount );
-                    if ( folder )
-                        trie->charmap[ folder[ uvc ] ] = trie->charmap[ uvc ];
-                    TRIE_STORE_REVCHAR;
+                    TRIE_STORE_REVCHAR( uvc );
                 }
                 if ( set_bit ) {
                    /* store the codepoint in the bitmap, and its folded
                     * equivalent. */
-                    TRIE_BITMAP_SET(trie,uvc);
+                    TRIE_BITMAP_SET(trie, uvc);
 
                    /* store the folded codepoint */
-                   if ( folder ) TRIE_BITMAP_SET(trie,folder[ uvc ]);
+                    if ( folder ) TRIE_BITMAP_SET(trie, folder[(U8) uvc ]);
 
                    if ( !UTF ) {
                        /* store first byte of utf8 representation of
@@ -1642,17 +1662,28 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
 
                 if ( !SvTRUE( *svpp ) ) {
                     sv_setiv( *svpp, ++trie->uniquecharcount );
-                    TRIE_STORE_REVCHAR;
+                    TRIE_STORE_REVCHAR(uvc);
                 }
             }
         }
         if( cur == first ) {
-            trie->minlen=chars;
-            trie->maxlen=chars;
+            trie->minlen = chars;
+            trie->maxlen = chars;
         } else if (chars < trie->minlen) {
-            trie->minlen=chars;
+            trie->minlen = chars;
         } else if (chars > trie->maxlen) {
-            trie->maxlen=chars;
+            trie->maxlen = chars;
+        }
+        if (OP( noper ) == EXACTFU_SS) {
+            /* XXX: workaround - 'ss' could match "\x{DF}" so minlen could be 1 and not 2*/
+           if (trie->minlen > 1)
+                trie->minlen= 1;
+        }
+       if (OP( noper ) == EXACTFU_TRICKYFOLD) {
+           /* XXX: workround - things like "\x{1FBE}\x{0308}\x{0301}" can match "\x{0390}" 
+            *                - We assume that any such sequence might match a 2 byte string */
+            if (trie->minlen > 2 )
+                trie->minlen= 2;
         }
 
     } /* end first pass */
@@ -1725,6 +1756,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
            STRLEN foldlen   = 0;         /* required init */
             U32 wordlen      = 0;         /* required init */
            U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
+            STRLEN skiplen   = 0;
 
             if (OP(noper) != NOTHING) {
                 for ( ; uc < e ; uc += len ) {
@@ -1925,8 +1957,10 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
 
             STRLEN foldlen   = 0;         /* required init */
             U32 wordlen      = 0;         /* required init */
+            STRLEN skiplen   = 0;
             U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
 
+
             if ( OP(noper) != NOTHING ) {
                 for ( ; uc < e ; uc += len ) {
 
@@ -2517,11 +2551,14 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
  * The adjacent nodes actually may be separated by NOTHING kind nodes, and
  * these get optimized out
  *
- * If there are problematic code sequences, *min_change is set to the delta
- * that the minimum size of the node can be off from its actual size.  And, the
- * node type of the result is changed to reflect that it contains these
+ * If there are problematic code sequences, *min_subtract is set to the delta
+ * that the minimum size of the node can be less than its actual size.  And,
+ * the node type of the result is changed to reflect that it contains these
  * sequences.
  *
+ * And *has_exactf_sharp_s is set to indicate whether or not the node is EXACTF
+ * and contains LATIN SMALL LETTER SHARP S
+ *
  * This is as good a place as any to discuss the design of handling these
  * problematic sequences.  It's been wrong in Perl for a very long time.  There
  * are three code points in Unicode whose folded lengths differ so much from
@@ -2529,20 +2566,20 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
  * construction.  Why only these are problematic, and not others where lengths
  * also differ is something I (khw) do not understand.  New versions of Unicode
  * might add more such code points.  Hopefully the logic in fold_grind.t that
- * figures out what to test (in part by veriying that each size-combination
+ * figures out what to test (in part by verifying that each size-combination
  * gets tested) will catch any that do come along, so they can be added to the
- * special handling below.  The chances of this are actually rather small, as
- * most, if not all, of the world's scripts that have casefolding have already
- * been encoded by Unicode.  Also, a number of Unicode's decisions were made to
- * allow compatibility with pre-existing standards, and almost all of those
- * have already been dealt with.  These would otherwise be the most likely
- * candidates for generating further tricky sequences.  In other words, Unicode
- * by itself is unlikely to add new ones unless it is for compatibility with
- * pre-existing standards.
+ * special handling below.  The chances of new ones are actually rather small,
+ * as most, if not all, of the world's scripts that have casefolding have
+ * already been encoded by Unicode.  Also, a number of Unicode's decisions were
+ * made to allow compatibility with pre-existing standards, and almost all of
+ * those have already been dealt with.  These would otherwise be the most
+ * likely candidates for generating further tricky sequences.  In other words,
+ * Unicode by itself is unlikely to add new ones unless it is for compatibility
+ * with pre-existing standards, and there aren't many of those left.
  *
  * The previous designs for dealing with these involved assigning a special
  * node for them.  This approach doesn't work, as evidenced by this example:
- *      "\xDFs" =~ /s\xDF/ui
+ *      "\xDFs" =~ /s\xDF/ui    # Used to fail before these patches
  * Both these fold to "sss", but if the pattern is parsed to create a node of
  * that would match just the \xDF, it won't be able to handle the case where a
  * successful match would have to cross the node's boundary.  The new approach
@@ -2552,14 +2589,15 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
  * There are a number of components to the approach (a lot of work for just
  * three code points!):
  * 1)   This routine examines each EXACTFish node that could contain the
- *      problematic sequences, and if found, returns in *min_change the total
- *      delta between the actual length of the string and one that could match
- *      it.  This delta is used by the caller to adjust the min length of the
- *      match, and the delta between min and max, so that the optimizer doesn't
- *      reject these possibilities based on size constraints
+ *      problematic sequences.  It returns in *min_subtract how much to
+ *      subtract from the the actual length of the string to get a real minimum
+ *      for one that could match it.  This number is usually 0 except for the
+ *      problematic sequences.  This delta is used by the caller to adjust the
+ *      min length of the match, and the delta between min and max, so that the
+ *      optimizer doesn't reject these possibilities based on size constraints.
  * 2)   These sequences are not currently correctly handled by the trie code
  *      either, so it changes the joined node type to ops that are not handled
- *      by trie's, those new ops being EXACTFU_SS and EXACTFU_NO_TRIE.
+ *      by trie's, those new ops being EXACTFU_SS and EXACTFU_TRICKYFOLD.
  * 3)   This is sufficient for the two Greek sequences (described below), but
  *      the one involving the Sharp s (\xDF) needs more.  The node type
  *      EXACTFU_SS is used for an EXACTFU node that contains at least one "ss"
@@ -2570,14 +2608,16 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
  *      takes advantage of this.  Generally, an EXACTFish node that is in UTF-8
  *      is pre-folded by regcomp.c.  This saves effort in regex matching.
  *      However, probably mostly for historical reasons, the pre-folding isn't
- *      done for non-UTF8 patterns.  The fold possibilities for these are quite
- *      simple, except for the sharp s.  All the ones that don't involve a
- *      UTF-8 target string are members of a fold-pair, and arrays are set up
- *      for all of them that quickly find the other member of the pair.  It
- *      might actually be faster to pre-fold these, but it isn't currently
- *      done, except for the sharp s.  Code elsewhere in this file makes sure
- *      that it gets folded to 'ss', even if the pattern isn't UTF-8.  This
- *      avoids the issues describe in the next item.
+ *      done for non-UTF8 patterns (and it can't be for EXACTF and EXACTFL
+ *      nodes, as what they fold to isn't known until runtime.)  The fold
+ *      possibilities for the non-UTF8 patterns are quite simple, except for
+ *      the sharp s.  All the ones that don't involve a UTF-8 target string
+ *      are members of a fold-pair, and arrays are set up for all of them
+ *      that quickly find the other member of the pair.  It might actually
+ *      be faster to pre-fold these, but it isn't currently done, except for
+ *      the sharp s.  Code elsewhere in this file makes sure that it gets
+ *      folded to 'ss', even if the pattern isn't UTF-8.  This avoids the
+ *      issues described in the next item.
  * 4)   A problem remains for the sharp s in EXACTF nodes.  Whether it matches
  *      'ss' or not is not knowable at compile time.  It will match iff the
  *      target string is in UTF-8, unlike the EXACTFU nodes, where it always
@@ -2592,21 +2632,23 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
  *      cases are either 1-1 folds when no UTF-8 is involved; or is true by
  *      virtue of having this file pre-fold UTF-8 patterns.   I'm
  *      reluctant to try to change this assumption, so instead the code punts.
- *      Elsewhere in this file, each EXACTF node is examined for the sharp s.
- *      If found, a flag is set that later causes the optimizer in this file to
- *      not set values for the floating and fixed string lengths, and thus
- *      avoid the optimizer code in regexec.c that makes this invalid
- *      assumption.  Thus, there is no optimization based on string lengths for
- *      EXACTF nodes that contain the sharp s.  This only happens for /id rules
- *      (which means the pattern isn't in UTF-8).
+ *      This routine examines EXACTF nodes for the sharp s, and returns a
+ *      boolean indicating whether or not the node is an EXACTF node that
+ *      contains a sharp s.  When it is true, the caller sets a flag that later
+ *      causes the optimizer in this file to not set values for the floating
+ *      and fixed string lengths, and thus avoids the optimizer code in
+ *      regexec.c that makes the invalid assumption.  Thus, there is no
+ *      optimization based on string lengths for EXACTF nodes that contain the
+ *      sharp s.  This only happens for /id rules (which means the pattern
+ *      isn't in UTF-8).
  */
 
-#define JOIN_EXACT(scan,min_change,flags) \
+#define JOIN_EXACT(scan,min_subtract,has_exactf_sharp_s, flags) \
     if (PL_regkind[OP(scan)] == EXACT) \
-        join_exact(pRExC_state,(scan),(min_change),(flags),NULL,depth+1)
+        join_exact(pRExC_state,(scan),(min_subtract),has_exactf_sharp_s, (flags),NULL,depth+1)
 
 STATIC U32
-S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, IV *min_change, U32 flags,regnode *val, U32 depth) {
+S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, UV *min_subtract, bool *has_exactf_sharp_s, U32 flags,regnode *val, U32 depth) {
     /* Merge several consecutive EXACTish nodes into one. */
     regnode *n = regnext(scan);
     U32 stringok = 1;
@@ -2683,28 +2725,38 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, IV *min_change, U32
        }
 #endif
     }
-#define GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS   0x0390
-#define IOTA_D_T       GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS
-#define GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS    0x03B0
-#define UPSILON_D_T    GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS
 
-    *min_change = 0;
+    *min_subtract = 0;
+    *has_exactf_sharp_s = FALSE;
 
     /* Here, all the adjacent mergeable EXACTish nodes have been merged.  We
      * can now analyze for sequences of problematic code points.  (Prior to
      * this final joining, sequences could have been split over boundaries, and
-     * hence missed).  The sequences only happen in folding */
+     * hence missed).  The sequences only happen in folding, hence for any
+     * non-EXACT EXACTish node */
     if (OP(scan) != EXACT) {
-        char *s, *t;
-        char * s0 = STRING(scan);
-        char * const s_end = s0 + STR_LEN(scan);
-
-       /* First we look at the sequences that can occur only in UTF-8 strings.
-        * The sequences are of length 6 */
-       if (UTF && STR_LEN(scan) >= 6) {
+        U8 *s;
+        U8 * s0 = (U8*) STRING(scan);
+        U8 * const s_end = s0 + STR_LEN(scan);
+
+       /* The below is perhaps overboard, but this allows us to save a test
+        * each time through the loop at the expense of a mask.  This is
+        * because on both EBCDIC and ASCII machines, 'S' and 's' differ by a
+        * single bit.  On ASCII they are 32 apart; on EBCDIC, they are 64.
+        * This uses an exclusive 'or' to find that bit and then inverts it to
+        * form a mask, with just a single 0, in the bit position where 'S' and
+        * 's' differ. */
+       const U8 S_or_s_mask = (U8) ~ ('S' ^ 's');
+       const U8 s_masked = 's' & S_or_s_mask;
+
+       /* One pass is made over the node's string looking for all the
+        * possibilities.  to avoid some tests in the loop, there are two main
+        * cases, for UTF-8 patterns (which can't have EXACTF nodes) and
+        * non-UTF-8 */
+       if (UTF) {
 
-           /* Two problematic code points in Unicode casefolding of EXACT
-            * nodes:
+           /* There are two problematic Greek code points in Unicode
+            * casefolding
             *
             * U+0390 - GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
             * U+03B0 - GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
@@ -2724,86 +2776,124 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan, IV *min_change, U32
             * minimum length computation.  (there are other code points that
             * also fold to these two sequences, but the delta is smaller)
             *
-            * What we'll do is to look for the tail four bytes, and then peek
-            * at the preceding two bytes to see whether we need to decrease
-            * the minimum length by four (six minus two).
+            * If these sequences are found, the minimum length is decreased by
+            * four (six minus two).
             *
-            * Thanks to the design of UTF-8, there cannot be false matches:
-            * A sequence of valid UTF-8 bytes cannot be a subsequence of
-            * another valid sequence of UTF-8 bytes. */
+            * Similarly, 'ss' may match the single char and byte LATIN SMALL
+            * LETTER SHARP S.  We decrease the min length by 1 for each
+            * occurrence of 'ss' found */
 
 #ifdef EBCDIC /* RD tunifold greek 0390 and 03B0 */
-           const char U390_first_byte = '\xb4';
-           const char U390_2nd_byte = '\x68';
-           const char U3B0_first_byte = '\xb5';
-           const char U3B0_2nd_byte = '\x46';
-           const char tail[] = "\xaf\x49\xaf\x42";
+#          define U390_first_byte 0xb4
+           const U8 U390_tail[] = "\x68\xaf\x49\xaf\x42";
+#          define U3B0_first_byte 0xb5
+           const U8 U3B0_tail[] = "\x46\xaf\x49\xaf\x42";
 #else
-           const char U390_first_byte = '\xce';
-           const char U390_2nd_byte = '\xb9';
-           const char U3B0_first_byte = '\xcf';
-           const char U3B0_2nd_byte = '\x85';
-           const char tail[] = "\xcc\x88\xcc\x81";
+#          define U390_first_byte 0xce
+           const U8 U390_tail[] = "\xb9\xcc\x88\xcc\x81";
+#          define U3B0_first_byte 0xcf
+           const U8 U3B0_tail[] = "\x85\xcc\x88\xcc\x81";
 #endif
-           const STRLEN tail_len = sizeof(tail) - 1;
-           for (s = s0 + 2;    /* +2 is to skip the non-tail */
-                s <= s_end - tail_len
-                  && (t = ninstr(s, s_end, tail, tail + tail_len));
-                s = t + tail_len)
+           const U8 len = sizeof(U390_tail); /* (-1 for NUL; +1 for 1st byte;
+                                                yields a net of 0 */
+           /* Examine the string for one of the problematic sequences */
+           for (s = s0;
+                s < s_end - 1; /* Can stop 1 before the end, as minimum length
+                                * sequence we are looking for is 2 */
+                s += UTF8SKIP(s))
            {
-               if ((t[-1] == U390_2nd_byte && t[-2] == U390_first_byte)
-                   || (t[-1] == U3B0_2nd_byte && t[-2] == U3B0_first_byte))
-               {
-                   *min_change -= 4;
 
-                   /* This can't currently be handled by tries, so change the
-                    * node type to indicate this. */
-                   if (OP(scan) == EXACTFU) {
-                       OP(scan) = EXACTFU_NO_TRIE;
-                   }
+               /* Look for the first byte in each problematic sequence */
+               switch (*s) {
+                   /* We don't have to worry about other things that fold to
+                    * 's' (such as the long s, U+017F), as all above-latin1
+                    * code points have been pre-folded */
+                   case 's':
+                   case 'S':
+
+                        /* Current character is an 's' or 'S'.  If next one is
+                         * as well, we have the dreaded sequence */
+                       if (((*(s+1) & S_or_s_mask) == s_masked)
+                           /* These two node types don't have special handling
+                            * for 'ss' */
+                           && OP(scan) != EXACTFL && OP(scan) != EXACTFA)
+                       {
+                           *min_subtract += 1;
+                           OP(scan) = EXACTFU_SS;
+                           s++;    /* No need to look at this character again */
+                       }
+                       break;
+
+                   case U390_first_byte:
+                       if (s_end - s >= len
+
+                           /* The 1's are because are skipping comparing the
+                            * first byte */
+                           && memEQ(s + 1, U390_tail, len - 1))
+                       {
+                           goto greek_sequence;
+                       }
+                       break;
+
+                   case U3B0_first_byte:
+                       if (! (s_end - s >= len
+                              && memEQ(s + 1, U3B0_tail, len - 1)))
+                       {
+                           break;
+                       }
+                     greek_sequence:
+                       *min_subtract += 4;
+
+                       /* This can't currently be handled by trie's, so change
+                        * the node type to indicate this.  If EXACTFA and
+                        * EXACTFL were ever to be handled by trie's, this
+                        * would have to be changed.  If this node has already
+                        * been changed to EXACTFU_SS in this loop, leave it as
+                        * is.  (I (khw) think it doesn't matter in regexec.c
+                        * for UTF patterns, but no need to change it */
+                       if (OP(scan) == EXACTFU) {
+                           OP(scan) = EXACTFU_TRICKYFOLD;
+                       }
+                       s += 6; /* We already know what this sequence is.  Skip
+                                  the rest of it */
+                       break;
                }
            }
        }
+       else if (OP(scan) != EXACTFL && OP(scan) != EXACTFA) {
 
-       /* The third problematic sequence is 'ss', which can match just the
-        * single byte LATIN SMALL LETTER SHARP S, and it can do it in both
-        * non- and UTF-8.  Code elsewhere in this file makes sure, however,
-        * that the sharp s gets folded to 'ss' under Unicode rules even if not
-        * UTF-8. */
-       if (STR_LEN(scan) >= 2
-           && (OP(scan) == EXACTFU
-               || OP(scan) == EXACTFU_NO_TRIE  /* The code above could have
-                                                  set to this node type */
-               || OP(scan) == EXACTF))
-       {
-           /* The string will be folded to 'ss' if it's in UTF-8, but it could
-             * include capital 'S' instead of lower case when not UTF-8.  We
-             * could have different code to handle the two cases, but this is
-             * not necessary since both S and s are invariants under UTF-8; and
-             * not worth it, especially because we can use just one test for
-             * either 'S' or 's' each * time through the loop (plus a mask).
-             * Ths is because on both EBCDIC and ASCII machines, 'S' and 's'
-             * differ by a single bit.  On ASCII they are 32 apart; on EBCDIC,
-             * they are 64.  This uses an exclusive 'or' to find that bit and
-             * then inverts it to form a mask, with just a single 0, in the bit
-             * position where 'S' and 's' differ. */
-           const char S_or_s_mask = ~ ('S' ^ 's');
-           const char s_masked = 's' & S_or_s_mask;
-
-           for (s = s0; s < s_end - 1; s++) {
-               if (((*s & S_or_s_mask) == s_masked)
-                   && ((*(s+1) & S_or_s_mask) == s_masked))
-               {
-                   s++;
-                   *min_change -= 1;
-
-                   /* EXACTFU_SS also isn't trie'able, so don't have to
-                    * preserve EXACTFU_NO_TRIE.  EXACTF is also not trie'able,
-                    * and because we essentially punt the optimizations in its
-                    * case, we don't need to indicate that it has an ss */
-                   if (OP(scan) == EXACTFU || OP(scan) == EXACTFU_NO_TRIE) {
-                       OP(scan) = EXACTFU_SS;
-                   }
+           /* Here, the pattern is not UTF-8.  We need to look only for the
+            * 'ss' sequence, and in the EXACTF case, the sharp s, which can be
+            * in the final position.  Otherwise we can stop looking 1 byte
+            * earlier because have to find both the first and second 's' */
+           const U8* upper = (OP(scan) == EXACTF) ? s_end : s_end -1;
+
+           for (s = s0; s < upper; s++) {
+               switch (*s) {
+                   case 'S':
+                   case 's':
+                       if (s_end - s > 1
+                           && ((*(s+1) & S_or_s_mask) == s_masked))
+                       {
+                           *min_subtract += 1;
+
+                           /* EXACTF nodes need to know that the minimum
+                            * length changed so that a sharp s in the string
+                            * can match this ss in the pattern, but they
+                            * remain EXACTF nodes, as they are not trie'able,
+                            * so don't have to invent a new node type to
+                            * exclude them from the trie code */
+                           if (OP(scan) != EXACTF) {
+                               OP(scan) = EXACTFU_SS;
+                           }
+                           s++;
+                       }
+                       break;
+                   case LATIN_SMALL_LETTER_SHARP_S:
+                       if (OP(scan) == EXACTF) {
+                           *has_exactf_sharp_s = TRUE;
+                       }
+                       break;
                }
            }
        }
@@ -2922,11 +3012,18 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
   fake_study_recurse:
     while ( scan && OP(scan) != END && scan < last ){
-        IV min_change = 0;
+        UV min_subtract = 0;    /* How much to subtract from the minimum node
+                                   length to get a real minimum (because the
+                                   folded version may be shorter) */
+       bool has_exactf_sharp_s = FALSE;
        /* Peephole optimizer: */
        DEBUG_STUDYDATA("Peep:", data,depth);
        DEBUG_PEEP("Peep",scan,depth);
-        JOIN_EXACT(scan,&min_change,0);
+
+        /* Its not clear to khw or hv why this is done here, and not in the
+         * clauses that deal with EXACT nodes.  khw's guess is that it's
+         * because of a previous design */
+        JOIN_EXACT(scan,&min_subtract, &has_exactf_sharp_s, 0);
 
        /* Follow the next-chain of the current node and optimize
           away all the NOTHINGs from it.  */
@@ -3117,7 +3214,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                         regnode *first = (regnode *)NULL;
                         regnode *last = (regnode *)NULL;
                         regnode *tail = scan;
-                        U8 optype = 0;
+                        U8 trietype = 0;
                         U32 count=0;
 
 #ifdef DEBUGGING
@@ -3148,32 +3245,59 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                         
                         /*
 
-                           step through the branches, cur represents each
-                           branch, noper is the first thing to be matched
-                           as part of that branch and noper_next is the
-                           regnext() of that node. if noper is an EXACT
-                           and noper_next is the same as scan (our current
-                           position in the regex) then the EXACT branch is
-                           a possible optimization target. Once we have
-                           two or more consecutive such branches we can
-                           create a trie of the EXACT's contents and stich
-                           it in place. If the sequence represents all of
-                           the branches we eliminate the whole thing and
-                           replace it with a single TRIE. If it is a
-                           subsequence then we need to stitch it in. This
-                           means the first branch has to remain, and needs
-                           to be repointed at the item on the branch chain
-                           following the last branch optimized. This could
-                           be either a BRANCH, in which case the
-                           subsequence is internal, or it could be the
-                           item following the branch sequence in which
-                           case the subsequence is at the end.
+                            Step through the branches
+                                cur represents each branch,
+                                noper is the first thing to be matched as part of that branch
+                                noper_next is the regnext() of that node.
+
+                            We normally handle a case like this /FOO[xyz]|BAR[pqr]/
+                            via a "jump trie" but we also support building with NOJUMPTRIE,
+                            which restricts the trie logic to structures like /FOO|BAR/.
+
+                            If noper is a trieable nodetype then the branch is a possible optimization
+                            target. If we are building under NOJUMPTRIE then we require that noper_next
+                            is the same as scan (our current position in the regex program).
+
+                            Once we have two or more consecutive such branches we can create a
+                            trie of the EXACT's contents and stitch it in place into the program.
+
+                            If the sequence represents all of the branches in the alternation we
+                            replace the entire thing with a single TRIE node.
+
+                            Otherwise when it is a subsequence we need to stitch it in place and
+                            replace only the relevant branches. This means the first branch has
+                            to remain as it is used by the alternation logic, and its next pointer,
+                            and needs to be repointed at the item on the branch chain following
+                            the last branch we have optimized away.
+
+                            This could be either a BRANCH, in which case the subsequence is internal,
+                            or it could be the item following the branch sequence in which case the
+                            subsequence is at the end (which does not necessarily mean the first node
+                            is the start of the alternation).
+
+                            TRIE_TYPE(X) is a define which maps the optype to a trietype.
+
+                                optype          |  trietype
+                                ----------------+-----------
+                                NOTHING         | NOTHING
+                                EXACT           | EXACT
+                                EXACTFU         | EXACTFU
+                                EXACTFU_SS      | EXACTFU
+                                EXACTFU_TRICKYFOLD | EXACTFU
+                                EXACTFA         | 0
+
 
                         */
+#define TRIE_TYPE(X) ( ( NOTHING == (X) ) ? NOTHING :   \
+                       ( EXACT == (X) )   ? EXACT :        \
+                       ( EXACTFU == (X) || EXACTFU_SS == (X) || EXACTFU_TRICKYFOLD == (X) ) ? EXACTFU :        \
+                       0 )
 
                         /* dont use tail as the end marker for this traverse */
                         for ( cur = startbranch ; cur != scan ; cur = regnext( cur ) ) {
                             regnode * const noper = NEXTOPER( cur );
+                            U8 noper_type = OP( noper );
+                            U8 noper_trietype = TRIE_TYPE( noper_type );
 #if defined(DEBUGGING) || defined(NOJUMPTRIE)
                             regnode * const noper_next = regnext( noper );
 #endif
@@ -3195,56 +3319,83 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                 PerlIO_printf( Perl_debug_log, "(First==%d,Last==%d,Cur==%d)\n",
                                    REG_NODE_NUM(first), REG_NODE_NUM(last), REG_NODE_NUM(cur) );
                             });
-                            if ( (((first && optype!=NOTHING) ? OP( noper ) == optype
-                                         : PL_regkind[ OP( noper ) ] == EXACT )
-                                  || OP(noper) == NOTHING )
+
+                            /* Is noper a trieable nodetype that can be merged with the
+                             * current trie (if there is one)? */
+                            if ( noper_trietype
+                                  &&
+                                  (
+                                        /* XXX: Currently we cannot allow a NOTHING node to be the first element
+                                         * of a TRIEABLE sequence, Otherwise we will overwrite the regop following
+                                         * the NOTHING with the TRIE regop later on. This is because a NOTHING node
+                                         * is only one regnode wide, and a TRIE is two regnodes. An example of a
+                                         * problematic pattern is: "x" =~ /\A(?>(?:(?:)A|B|C?x))\z/
+                                         * At a later point of time we can somewhat workaround this by handling
+                                         * NOTHING -> EXACT sequences as generated by /(?:)A|(?:)B/ type patterns,
+                                         * as we can effectively ignore the NOTHING regop in that case.
+                                         * This clause, which allows NOTHING to start a sequence is left commented
+                                         * out as a reference.
+                                         * - Yves
+
+                                           ( noper_trietype == NOTHING)
+                                           || ( trietype == NOTHING )
+                                        */
+                                        ( noper_trietype == NOTHING && trietype )
+                                        || ( trietype == noper_trietype )
+                                  )
 #ifdef NOJUMPTRIE
                                   && noper_next == tail
 #endif
                                   && count < U16_MAX)
                             {
+                                /* Handle mergable triable node
+                                 * Either we are the first node in a new trieable sequence,
+                                 * in which case we do some bookkeeping, otherwise we update
+                                 * the end pointer. */
                                 count++;
-                                if ( !first || optype == NOTHING ) {
-                                    if (!first) first = cur;
-                                    optype = OP( noper );
+                                if ( !first ) {
+                                    first = cur;
+                                    trietype = noper_trietype;
                                 } else {
+                                    if ( trietype == NOTHING )
+                                        trietype = noper_trietype;
                                     last = cur;
                                 }
-                            } else {
-/* 
-    Currently the trie logic handles case insensitive matching properly only
-    when the pattern is UTF-8 and the node is EXACTFU (thus forcing unicode
-    semantics).
-
-    If/when this is fixed the following define can be swapped
-    in below to fully enable trie logic.
-
-#define TRIE_TYPE_IS_SAFE 1
-
-*/
-#define TRIE_TYPE_IS_SAFE ((UTF && optype == EXACTFU) || optype==EXACT)
-
-                                if ( last && TRIE_TYPE_IS_SAFE ) {
-                                    make_trie( pRExC_state, 
-                                            startbranch, first, cur, tail, count, 
-                                            optype, depth+1 );
+                            } /* end handle mergable triable node */
+                            else {
+                                /* handle unmergable node -
+                                 * noper may either be a triable node which can not be tried
+                                 * together with the current trie, or a non triable node */
+                                if ( last ) {
+                                    /* If last is set and trietype is not NOTHING then we have found
+                                     * at least two triable branch sequences in a row of a similar
+                                     * trietype so we can turn them into a trie. If/when we
+                                     * allow NOTHING to start a trie sequence this condition will be
+                                     * required, and it isn't expensive so we leave it in for now. */
+                                    if ( trietype != NOTHING )
+                                        make_trie( pRExC_state,
+                                                startbranch, first, cur, tail, count,
+                                                trietype, depth+1 );
+                                    last = NULL; /* note: we clear/update first, trietype etc below, so we dont do it here */
                                 }
-                                if ( PL_regkind[ OP( noper ) ] == EXACT
+                                if ( noper_trietype
 #ifdef NOJUMPTRIE
                                      && noper_next == tail
 #endif
                                 ){
+                                    /* noper is triable, so we can start a new trie sequence */
                                     count = 1;
                                     first = cur;
-                                    optype = OP( noper );
-                                } else {
+                                    trietype = noper_trietype;
+                                } else if (first) {
+                                    /* if we already saw a first but the current node is not triable then we have
+                                     * to reset the first information. */
                                     count = 0;
                                     first = NULL;
-                                    optype = 0;
+                                    trietype = 0;
                                 }
-                                last = NULL;
-                            }
-                        }
+                            } /* end handle unmergable node */
+                        } /* loop over branches */
                         DEBUG_OPTIMISE_r({
                             regprop(RExC_rx, mysv, cur);
                             PerlIO_printf( Perl_debug_log,
@@ -3252,9 +3403,11 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                               "", SvPV_nolen_const( mysv ),REG_NODE_NUM(cur));
 
                         });
-                        
-                        if ( last && TRIE_TYPE_IS_SAFE ) {
-                            made= make_trie( pRExC_state, startbranch, first, scan, tail, count, optype, depth+1 );
+                        if ( last && trietype != NOTHING ) {
+                            /* the last branch of the sequence was part of a trie,
+                             * so we have to construct it here outside of the loop
+                             */
+                            made= make_trie( pRExC_state, startbranch, first, scan, tail, count, trietype, depth+1 );
 #ifdef TRIE_STUDY_OPT
                             if ( ((made == MADE_EXACT_TRIE && 
                                  startbranch == first) 
@@ -3268,8 +3421,8 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                 }
                             }
 #endif
-                        }
-                    }
+                        } /* end if ( last) */
+                    } /* TRIE_MAXBUF is non zero */
                     
                 } /* do trie */
                 
@@ -3342,8 +3495,8 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            UV uc;
            if (UTF) {
                const U8 * const s = (U8*)STRING(scan);
+               uc = utf8_to_uvchr_buf(s, s + l, NULL);
                l = utf8_length(s, s + l);
-               uc = utf8_to_uvchr(s, NULL);
            } else {
                uc = *((U8*)STRING(scan));
            }
@@ -3437,26 +3590,24 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            }
            if (UTF) {
                const U8 * const s = (U8 *)STRING(scan);
+               uc = utf8_to_uvchr_buf(s, s + l, NULL);
                l = utf8_length(s, s + l);
-               uc = utf8_to_uvchr(s, NULL);
            }
-           else if (OP(scan) == EXACTF) {
-               if (memchr(STRING(scan), LATIN_SMALL_LETTER_SHARP_S, l)) {
-                   RExC_seen |= REG_SEEN_EXACTF_SHARP_S;
-               }
+           else if (has_exactf_sharp_s) {
+               RExC_seen |= REG_SEEN_EXACTF_SHARP_S;
            }
-           min += l + min_change;
+           min += l - min_subtract;
             if (min < 0) {
                 min = 0;
             }
-            delta += abs(min_change);
+            delta += min_subtract;
            if (flags & SCF_DO_SUBSTR) {
-               data->pos_min += l + min_change;
+               data->pos_min += l - min_subtract;
                if (data->pos_min < 0) {
                     data->pos_min = 0;
                 }
-                data->pos_delta += abs(min_change);
-               if (min_change) {
+                data->pos_delta += min_subtract;
+               if (min_subtract) {
                    data->longest = &(data->longest_float);
                }
            }
@@ -3487,11 +3638,12 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                        /* Also set the other member of the fold pair.  In case
                         * that unicode semantics is called for at runtime, use
                         * the full latin1 fold.  (Can't do this for locale,
-                        * because not known until runtime */
+                        * because not known until runtime) */
                        ANYOF_BITMAP_SET(data->start_class, PL_fold_latin1[uc]);
 
-                       /* All folds except under /iaa that include s, S, and
-                        * sharp_s also may include the others */
+                        /* All other (EXACTFL handled above) folds except under
+                         * /iaa that include s, S, and sharp_s also may include
+                         * the others */
                        if (OP(scan) != EXACTFA) {
                            if (uc == 's' || uc == 'S') {
                                ANYOF_BITMAP_SET(data->start_class,
@@ -3944,18 +4096,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                data->longest = &(data->longest_float);
            }
        }
-       else if (OP(scan) == FOLDCHAR) {
-           int d = ARG(scan) == LATIN_SMALL_LETTER_SHARP_S ? 1 : 2;
-           flags &= ~SCF_DO_STCLASS;
-            min += 1;
-            delta += d;
-            if (flags & SCF_DO_SUBSTR) {
-               SCAN_COMMIT(pRExC_state,data,minlenp);  /* Cannot expect anything... */
-               data->pos_min += 1;
-               data->pos_delta += d;
-               data->longest = &(data->longest_float);
-           }
-       }
        else if (REGNODE_SIMPLE(OP(scan))) {
            int value = 0;
 
@@ -4760,6 +4900,64 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
 
     DEBUG_r(if (!PL_colorset) reginitcolors());
 
+#ifndef PERL_IN_XSUB_RE
+    /* Initialize these here instead of as-needed, as is quick and avoids
+     * having to test them each time otherwise */
+    if (! PL_AboveLatin1) {
+       PL_AboveLatin1 = _new_invlist_C_array(AboveLatin1_invlist);
+       PL_ASCII = _new_invlist_C_array(ASCII_invlist);
+       PL_Latin1 = _new_invlist_C_array(Latin1_invlist);
+
+       PL_L1PosixAlnum = _new_invlist_C_array(L1PosixAlnum_invlist);
+       PL_PosixAlnum = _new_invlist_C_array(PosixAlnum_invlist);
+
+       PL_L1PosixAlpha = _new_invlist_C_array(L1PosixAlpha_invlist);
+       PL_PosixAlpha = _new_invlist_C_array(PosixAlpha_invlist);
+
+       PL_PosixBlank = _new_invlist_C_array(PosixBlank_invlist);
+       PL_XPosixBlank = _new_invlist_C_array(XPosixBlank_invlist);
+
+       PL_L1Cased = _new_invlist_C_array(L1Cased_invlist);
+
+       PL_PosixCntrl = _new_invlist_C_array(PosixCntrl_invlist);
+       PL_XPosixCntrl = _new_invlist_C_array(XPosixCntrl_invlist);
+
+       PL_PosixDigit = _new_invlist_C_array(PosixDigit_invlist);
+
+       PL_L1PosixGraph = _new_invlist_C_array(L1PosixGraph_invlist);
+       PL_PosixGraph = _new_invlist_C_array(PosixGraph_invlist);
+
+       PL_L1PosixAlnum = _new_invlist_C_array(L1PosixAlnum_invlist);
+       PL_PosixAlnum = _new_invlist_C_array(PosixAlnum_invlist);
+
+       PL_L1PosixLower = _new_invlist_C_array(L1PosixLower_invlist);
+       PL_PosixLower = _new_invlist_C_array(PosixLower_invlist);
+
+       PL_L1PosixPrint = _new_invlist_C_array(L1PosixPrint_invlist);
+       PL_PosixPrint = _new_invlist_C_array(PosixPrint_invlist);
+
+       PL_L1PosixPunct = _new_invlist_C_array(L1PosixPunct_invlist);
+       PL_PosixPunct = _new_invlist_C_array(PosixPunct_invlist);
+
+       PL_PerlSpace = _new_invlist_C_array(PerlSpace_invlist);
+       PL_XPerlSpace = _new_invlist_C_array(XPerlSpace_invlist);
+
+       PL_PosixSpace = _new_invlist_C_array(PosixSpace_invlist);
+       PL_XPosixSpace = _new_invlist_C_array(XPosixSpace_invlist);
+
+       PL_L1PosixUpper = _new_invlist_C_array(L1PosixUpper_invlist);
+       PL_PosixUpper = _new_invlist_C_array(PosixUpper_invlist);
+
+       PL_VertSpace = _new_invlist_C_array(VertSpace_invlist);
+
+       PL_PosixWord = _new_invlist_C_array(PosixWord_invlist);
+       PL_L1PosixWord = _new_invlist_C_array(L1PosixWord_invlist);
+
+       PL_PosixXDigit = _new_invlist_C_array(PosixXDigit_invlist);
+       PL_XPosixXDigit = _new_invlist_C_array(XPosixXDigit_invlist);
+    }
+#endif
+
     exp = SvPV(pattern, plen);
 
     if (plen == 0) { /* ignore the utf8ness if the pattern is 0 length */
@@ -5271,6 +5469,7 @@ reStudy:
         {
             I32 t,ml;
 
+            /* See comments for join_exact for why REG_SEEN_EXACTF_SHARP_S */
            if ((RExC_seen & REG_SEEN_EXACTF_SHARP_S)
                || (SvCUR(data.longest_fixed)  /* ok to leave SvCUR */
                    && data.offset_fixed == data.offset_float_min
@@ -5317,6 +5516,8 @@ reStudy:
            Be careful. 
          */
        longest_fixed_length = CHR_SVLEN(data.longest_fixed);
+
+        /* See comments for join_exact for why REG_SEEN_EXACTF_SHARP_S */
        if (! (RExC_seen & REG_SEEN_EXACTF_SHARP_S)
            && (longest_fixed_length
                || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
@@ -6084,7 +6285,19 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
 #define INVLIST_LEN_OFFSET 0   /* Number of elements in the inversion list */
 #define INVLIST_ITER_OFFSET 1  /* Current iteration position */
 
-#define INVLIST_ZERO_OFFSET 2  /* 0 or 1; must be last element in header */
+/* This is a combination of a version and data structure type, so that one
+ * being passed in can be validated to be an inversion list of the correct
+ * vintage.  When the structure of the header is changed, a new random number
+ * in the range 2**31-1 should be generated and the new() method changed to
+ * insert that at this location.  Then, if an auxiliary program doesn't change
+ * correspondingly, it will be discovered immediately */
+#define INVLIST_VERSION_ID_OFFSET 2
+#define INVLIST_VERSION_ID 1064334010
+
+/* For safety, when adding new elements, remember to #undef them at the end of
+ * the inversion list code section */
+
+#define INVLIST_ZERO_OFFSET 3  /* 0 or 1; must be last element in header */
 /* The UV at position ZERO contains either 0 or 1.  If 0, the inversion list
  * contains the code point U+00000, and begins here.  If 1, the inversion list
  * doesn't contain U+0000, and it begins at the next UV in the array.
@@ -6244,10 +6457,39 @@ Perl__new_invlist(pTHX_ IV initial_size)
      * properly */
     *get_invlist_zero_addr(new_list) = UV_MAX;
 
+    *get_invlist_version_id_addr(new_list) = INVLIST_VERSION_ID;
+#if HEADER_LENGTH != 4
+#   error Need to regenerate VERSION_ID by running perl -E 'say int(rand 2**31-1)', and then changing the #if to the new length
+#endif
+
     return new_list;
 }
 #endif
 
+STATIC SV*
+S__new_invlist_C_array(pTHX_ UV* list)
+{
+    /* Return a pointer to a newly constructed inversion list, initialized to
+     * point to <list>, which has to be in the exact correct inversion list
+     * form, including internal fields.  Thus this is a dangerous routine that
+     * should not be used in the wrong hands */
+
+    SV* invlist = newSV_type(SVt_PV);
+
+    PERL_ARGS_ASSERT__NEW_INVLIST_C_ARRAY;
+
+    SvPV_set(invlist, (char *) list);
+    SvLEN_set(invlist, 0);  /* Means we own the contents, and the system
+                              shouldn't touch it */
+    SvCUR_set(invlist, TO_INTERNAL_SIZE(invlist_len(invlist)));
+
+    if (*get_invlist_version_id_addr(invlist) != INVLIST_VERSION_ID) {
+        Perl_croak(aTHX_ "panic: Incorrect version for previously generated inversion list");
+    }
+
+    return invlist;
+}
+
 STATIC void
 S_invlist_extend(pTHX_ SV* const invlist, const UV new_max)
 {
@@ -6274,6 +6516,8 @@ S_invlist_trim(pTHX_ SV* const invlist)
 #define ELEMENT_RANGE_MATCHES_INVLIST(i) (! ((i) & 1))
 #define PREV_RANGE_MATCHES_INVLIST(i) (! ELEMENT_RANGE_MATCHES_INVLIST(i))
 
+#define _invlist_union_complement_2nd(a, b, output) _invlist_union_maybe_complement_2nd(a, b, TRUE, output)
+
 #ifndef PERL_IN_XSUB_RE
 void
 Perl__append_range_to_invlist(pTHX_ SV* const invlist, const UV start, const UV end)
@@ -6479,12 +6723,17 @@ Perl__invlist_populate_swatch(pTHX_ SV* const invlist, const UV start, const UV
     return;
 }
 
+
 void
-Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
+Perl__invlist_union_maybe_complement_2nd(pTHX_ SV* const a, SV* const b, bool complement_b, SV** output)
 {
     /* Take the union of two inversion lists and point <output> to it.  *output
      * should be defined upon input, and if it points to one of the two lists,
-     * the reference count to that list will be decremented.
+     * the reference count to that list will be decremented.  The first list,
+     * <a>, may be NULL, in which case a copy of the second list is returned.
+     * If <complement_b> is TRUE, the union is taken of the complement
+     * (inversion) of <b> instead of b itself.
+     *
      * The basis for this comes from "Unicode Demystified" Chapter 13 by
      * Richard Gillam, published by Addison-Wesley, and explained at some
      * length there.  The preface says to incorporate its examples into your
@@ -6519,17 +6768,21 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
      */
     UV count = 0;
 
-    PERL_ARGS_ASSERT__INVLIST_UNION;
+    PERL_ARGS_ASSERT__INVLIST_UNION_MAYBE_COMPLEMENT_2ND;
     assert(a != b);
 
     /* If either one is empty, the union is the other one */
-    len_a = invlist_len(a);
-    if (len_a == 0) {
+    if (a == NULL || ((len_a = invlist_len(a)) == 0)) {
        if (*output == a) {
-           SvREFCNT_dec(a);
+            if (a != NULL) {
+                SvREFCNT_dec(a);
+            }
        }
        if (*output != b) {
            *output = invlist_clone(b);
+            if (complement_b) {
+                _invlist_invert(*output);
+            }
        } /* else *output already = b; */
        return;
     }
@@ -6537,10 +6790,20 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
        if (*output == b) {
            SvREFCNT_dec(b);
        }
-       if (*output != a) {
-           *output = invlist_clone(a);
-       }
-       /* else *output already = a; */
+
+        /* The complement of an empty list is a list that has everything in it,
+         * so the union with <a> includes everything too */
+        if (complement_b) {
+            if (a == *output) {
+                SvREFCNT_dec(a);
+            }
+            *output = _new_invlist(1);
+            _append_range_to_invlist(*output, 0, UV_MAX);
+        }
+        else if (*output != a) {
+            *output = invlist_clone(a);
+        }
+        /* else *output already = a; */
        return;
     }
 
@@ -6548,6 +6811,31 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
     array_a = invlist_array(a);
     array_b = invlist_array(b);
 
+    /* If are to take the union of 'a' with the complement of b, set it
+     * up so are looking at b's complement. */
+    if (complement_b) {
+
+       /* To complement, we invert: if the first element is 0, remove it.  To
+        * do this, we just pretend the array starts one later, and clear the
+        * flag as we don't have to do anything else later */
+        if (array_b[0] == 0) {
+            array_b++;
+            len_b--;
+            complement_b = FALSE;
+        }
+        else {
+
+            /* But if the first element is not zero, we unshift a 0 before the
+             * array.  The data structure reserves a space for that 0 (which
+             * should be a '1' right now), so physical shifting is unneeded,
+             * but temporarily change that element to 0.  Before exiting the
+             * routine, we must restore the element to '1' */
+            array_b--;
+            len_b++;
+            array_b[0] = 0;
+        }
+    }
+
     /* Size the union for the worst case: that the sets are completely
      * disjoint */
     u = _new_invlist(len_a + len_b);
@@ -6666,16 +6954,24 @@ Perl__invlist_union(pTHX_ SV* const a, SV* const b, SV** output)
        SvREFCNT_dec(*output);
     }
 
+    /* If we've changed b, restore it */
+    if (complement_b) {
+        array_b[0] = 1;
+    }
+
     *output = u;
     return;
 }
 
 void
-Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
+Perl__invlist_intersection_maybe_complement_2nd(pTHX_ SV* const a, SV* const b, bool complement_b, SV** i)
 {
     /* Take the intersection of two inversion lists and point <i> to it.  *i
      * should be defined upon input, and if it points to one of the two lists,
      * the reference count to that list will be decremented.
+     * If <complement_b> is TRUE, the result will be the intersection of <a>
+     * and the complement (or inversion) of <b> instead of <b> directly.
+     *
      * The basis for this comes from "Unicode Demystified" Chapter 13 by
      * Richard Gillam, published by Addison-Wesley, and explained at some
      * length there.  The preface says to incorporate its examples into your
@@ -6706,22 +7002,38 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
      */
     UV count = 0;
 
-    PERL_ARGS_ASSERT__INVLIST_INTERSECTION;
+    PERL_ARGS_ASSERT__INVLIST_INTERSECTION_MAYBE_COMPLEMENT_2ND;
     assert(a != b);
 
-    /* If either one is empty, the intersection is null */
+    /* Special case if either one is empty */
     len_a = invlist_len(a);
     if ((len_a == 0) || ((len_b = invlist_len(b)) == 0)) {
 
-       /* If the result is the same as one of the inputs, the input is being
-        * overwritten */
+        if (len_a != 0 && complement_b) {
+
+            /* Here, 'a' is not empty, therefore from the above 'if', 'b' must
+             * be empty.  Here, also we are using 'b's complement, which hence
+             * must be every possible code point.  Thus the intersection is
+             * simply 'a'. */
+            if (*i != a) {
+                *i = invlist_clone(a);
+
+                if (*i == b) {
+                    SvREFCNT_dec(b);
+                }
+            }
+            /* else *i is already 'a' */
+            return;
+        }
+
+        /* Here, 'a' or 'b' is empty and not using the complement of 'b'.  The
+         * intersection must be empty */
        if (*i == a) {
            SvREFCNT_dec(a);
        }
        else if (*i == b) {
            SvREFCNT_dec(b);
        }
-
        *i = _new_invlist(0);
        return;
     }
@@ -6730,6 +7042,31 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
     array_a = invlist_array(a);
     array_b = invlist_array(b);
 
+    /* If are to take the intersection of 'a' with the complement of b, set it
+     * up so are looking at b's complement. */
+    if (complement_b) {
+
+       /* To complement, we invert: if the first element is 0, remove it.  To
+        * do this, we just pretend the array starts one later, and clear the
+        * flag as we don't have to do anything else later */
+        if (array_b[0] == 0) {
+            array_b++;
+            len_b--;
+            complement_b = FALSE;
+        }
+        else {
+
+            /* But if the first element is not zero, we unshift a 0 before the
+             * array.  The data structure reserves a space for that 0 (which
+             * should be a '1' right now), so physical shifting is unneeded,
+             * but temporarily change that element to 0.  Before exiting the
+             * routine, we must restore the element to '1' */
+            array_b--;
+            len_b++;
+            array_b[0] = 0;
+        }
+    }
+
     /* Size the intersection for the worst case: that the intersection ends up
      * fragmenting everything to be completely disjoint */
     r= _new_invlist(len_a + len_b);
@@ -6838,6 +7175,11 @@ Perl__invlist_intersection(pTHX_ SV* const a, SV* const b, SV** i)
        SvREFCNT_dec(*i);
     }
 
+    /* If we've changed b, restore it */
+    if (complement_b) {
+        array_b[0] = 1;
+    }
+
     *i = r;
     return;
 }
@@ -6979,46 +7321,6 @@ S_invlist_clone(pTHX_ SV* const invlist)
     return new_invlist;
 }
 
-#ifndef PERL_IN_XSUB_RE
-void
-Perl__invlist_subtract(pTHX_ SV* const a, SV* const b, SV** result)
-{
-    /* Point <result> to an inversion list which consists of all elements in
-     * <a> that aren't also in <b>.  *result should be defined upon input, and
-     * if it points to C<b> its reference count will be decremented. */
-
-    PERL_ARGS_ASSERT__INVLIST_SUBTRACT;
-    assert(a != b);
-
-    /* Subtracting nothing retains the original */
-    if (invlist_len(b) == 0) {
-
-       if (*result == b) {
-           SvREFCNT_dec(b);
-       }
-
-       /* If the result is not to be the same variable as the original, create
-        * a copy */
-       if (*result != a) {
-           *result = invlist_clone(a);
-       }
-    } else {
-       SV *b_copy = invlist_clone(b);
-       _invlist_invert(b_copy);        /* Everything not in 'b' */
-
-       if (*result == b) {
-           SvREFCNT_dec(b);
-       }
-
-       _invlist_intersection(a, b_copy, result);    /* Everything in 'a' not in
-                                                      'b' */
-       SvREFCNT_dec(b_copy);
-    }
-
-    return;
-}
-#endif
-
 PERL_STATIC_INLINE UV*
 S_get_invlist_iter_addr(pTHX_ SV* invlist)
 {
@@ -7030,6 +7332,16 @@ S_get_invlist_iter_addr(pTHX_ SV* invlist)
     return (UV *) (SvPVX(invlist) + (INVLIST_ITER_OFFSET * sizeof (UV)));
 }
 
+PERL_STATIC_INLINE UV*
+S_get_invlist_version_id_addr(pTHX_ SV* invlist)
+{
+    /* Return the address of the UV that contains the version id. */
+
+    PERL_ARGS_ASSERT_GET_INVLIST_VERSION_ID_ADDR;
+
+    return (UV *) (SvPVX(invlist) + (INVLIST_VERSION_ID_OFFSET * sizeof (UV)));
+}
+
 PERL_STATIC_INLINE void
 S_invlist_iterinit(pTHX_ SV* invlist)  /* Initialize iterator for invlist */
 {
@@ -7135,6 +7447,7 @@ S_invlist_dump(pTHX_ SV* const invlist, const char * const header)
 #undef INVLIST_LEN_OFFSET
 #undef INVLIST_ZERO_OFFSET
 #undef INVLIST_ITER_OFFSET
+#undef INVLIST_VERSION_ID
 
 /* End of inversion list object */
 
@@ -7781,9 +8094,12 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                 U32 posflags = 0, negflags = 0;
                U32 *flagsp = &posflags;
                 char has_charset_modifier = '\0';
-               regex_charset cs = (RExC_utf8 || RExC_uni_semantics)
-                                   ? REGEX_UNICODE_CHARSET
-                                   : REGEX_DEPENDS_CHARSET;
+               regex_charset cs = get_regex_charset(RExC_flags);
+               if (cs == REGEX_DEPENDS_CHARSET
+                   && (RExC_utf8 || RExC_uni_semantics))
+               {
+                   cs = REGEX_UNICODE_CHARSET;
+               }
 
                while (*RExC_parse) {
                    /* && strchr("iogcmsx", *RExC_parse) */
@@ -9215,7 +9531,6 @@ tryagain:
            char *s;
            STRLEN foldlen;
            U8 tmpbuf[UTF8_MAXBYTES_CASE+1], *foldbuf;
-           regnode * orig_emit;
             U8 node_type;
 
            /* Is this a LATIN LOWER CASE SHARP S in an EXACTFU node?  If so,
@@ -9223,9 +9538,6 @@ tryagain:
            bool is_exactfu_sharp_s;
 
            ender = 0;
-           orig_emit = RExC_emit; /* Save the original output node position in
-                                     case we need to output a different node
-                                     type */
             node_type = ((! FOLD) ? EXACT
                        : (LOC)
                          ? EXACTFL
@@ -9458,7 +9770,8 @@ tryagain:
                    /* Prime the casefolded buffer.  Locale rules, which apply
                     * only to code points < 256, aren't known until execution,
                     * so for them, just output the original character using
-                    * utf8 */
+                     * utf8.  If we start to fold non-UTF patterns, be sure to
+                     * update join_exact() */
                    if (LOC && ender < 256) {
                        if (UNI_IS_INVARIANT(ender)) {
                            *tmpbuf = (U8) ender;
@@ -9524,7 +9837,10 @@ tryagain:
                              for (foldbuf = tmpbuf;
                                   foldlen;
                                   foldlen -= numlen) {
-                                  ender = utf8_to_uvchr(foldbuf, &numlen);
+
+                                  /* tmpbuf has been constructed by us, so we
+                                   * know it is valid utf8 */
+                                  ender = valid_utf8_to_uvchr(foldbuf, &numlen);
                                   if (numlen > 0) {
                                        const STRLEN unilen = reguni(pRExC_state, ender, s);
                                        s       += unilen;
@@ -9560,7 +9876,7 @@ tryagain:
                          for (foldbuf = tmpbuf;
                               foldlen;
                               foldlen -= numlen) {
-                              ender = utf8_to_uvchr(foldbuf, &numlen);
+                              ender = valid_utf8_to_uvchr(foldbuf, &numlen);
                               if (numlen > 0) {
                                    const STRLEN unilen = reguni(pRExC_state, ender, s);
                                    len     += unilen;
@@ -9807,91 +10123,132 @@ S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
     }
 }
 
-/* No locale test, and always Unicode semantics, no ignore-case differences */
-#define _C_C_T_NOLOC_(NAME,TEST,WORD)                                          \
-ANYOF_##NAME:                                                                  \
-       for (value = 0; value < 256; value++)                                  \
-           if (TEST)                                                          \
-           stored += set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);  \
-    yesno = '+';                                                               \
-    what = WORD;                                                               \
-    break;                                                                     \
-case ANYOF_N##NAME:                                                            \
-       for (value = 0; value < 256; value++)                                  \
-           if (!TEST)                                                         \
-           stored += set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);  \
-    yesno = '!';                                                               \
-    what = WORD;                                                               \
-    break
-
-/* Like the above, but there are differences if we are in uni-8-bit or not, so
- * there are two tests passed in, to use depending on that. There aren't any
- * cases where the label is different from the name, so no need for that
- * parameter.
- * Sets 'what' to WORD which is the property name for non-bitmap code points;
- * But, uses FOLD_WORD instead if /i has been selected, to allow a different
- * property name */
-#define _C_C_T_(NAME, TEST_8, TEST_7, WORD, FOLD_WORD)                         \
-ANYOF_##NAME:                                                                  \
-    if (LOC) ANYOF_CLASS_SET(ret, ANYOF_##NAME);                               \
-    else if (UNI_SEMANTICS) {                                                  \
-        for (value = 0; value < 256; value++) {                                \
-            if (TEST_8(value)) stored +=                                       \
-                      set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);  \
-        }                                                                      \
-    }                                                                          \
-    else {                                                                     \
-        for (value = 0; value < 128; value++) {                                \
-            if (TEST_7(UNI_TO_NATIVE(value))) stored +=                        \
-               set_regclass_bit(pRExC_state, ret,                     \
-                                  (U8) UNI_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);                 \
-        }                                                                      \
-    }                                                                          \
-    yesno = '+';                                                               \
-    if (FOLD) {                                                                \
-        what = FOLD_WORD;                                                      \
-    }                                                                          \
-    else {                                                                     \
-        what = WORD;                                                           \
-    }                                                                          \
-    break;                                                                     \
-case ANYOF_N##NAME:                                                            \
-    if (LOC) ANYOF_CLASS_SET(ret, ANYOF_N##NAME);                              \
-    else if (UNI_SEMANTICS) {                                                  \
-        for (value = 0; value < 256; value++) {                                \
-            if (! TEST_8(value)) stored +=                                     \
-                   set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);    \
-        }                                                                      \
-    }                                                                          \
-    else {                                                                     \
-        for (value = 0; value < 128; value++) {                                \
-            if (! TEST_7(UNI_TO_NATIVE(value))) stored += set_regclass_bit(  \
-                       pRExC_state, ret, (U8) UNI_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);    \
-        }                                                                      \
-       if (AT_LEAST_ASCII_RESTRICTED) {                                       \
-           for (value = 128; value < 256; value++) {                          \
-             stored += set_regclass_bit(                                     \
-                          pRExC_state, ret, (U8) UNI_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate); \
-           }                                                                  \
-           ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;                             \
-       }                                                                      \
-       else {                                                                 \
-           /* For a non-ut8 target string with DEPENDS semantics, all above   \
-            * ASCII Latin1 code points match the complement of any of the     \
-            * classes.  But in utf8, they have their Unicode semantics, so    \
-            * can't just set them in the bitmap, or else regexec.c will think \
-            * they matched when they shouldn't. */                            \
-           ANYOF_FLAGS(ret) |= ANYOF_NON_UTF8_LATIN1_ALL;                     \
-       }                                                                      \
-    }                                                                          \
-    yesno = '!';                                                               \
-    if (FOLD) {                                                                \
-        what = FOLD_WORD;                                                      \
-    }                                                                          \
-    else {                                                                     \
-        what = WORD;                                                           \
-    }                                                                          \
-    break
+/* Generate the code to add a full posix character <class> to the bracketed
+ * character class given by <node>.  (<node> is needed only under locale rules)
+ * destlist     is the inversion list for non-locale rules that this class is
+ *              to be added to
+ * sourcelist   is the ASCII-range inversion list to add under /a rules
+ * Xsourcelist  is the full Unicode range list to use otherwise. */
+#define DO_POSIX(node, class, destlist, sourcelist, Xsourcelist)           \
+    if (LOC) {                                                             \
+       SV* scratch_list = NULL;                                           \
+                                                                           \
+        /* Set this class in the node for runtime matching */              \
+        ANYOF_CLASS_SET(node, class);                                      \
+                                                                           \
+        /* For above Latin1 code points, we use the full Unicode range */  \
+        _invlist_intersection(PL_AboveLatin1,                              \
+                              Xsourcelist,                                 \
+                              &scratch_list);                              \
+        /* And set the output to it, adding instead if there already is an \
+        * output.  Checking if <destlist> is NULL first saves an extra    \
+        * clone.  Its reference count will be decremented at the next     \
+        * union, etc, or if this is the only instance, at the end of the  \
+        * routine */                                                      \
+        if (! destlist) {                                                  \
+            destlist = scratch_list;                                       \
+        }                                                                  \
+        else {                                                             \
+            _invlist_union(destlist, scratch_list, &destlist);             \
+            SvREFCNT_dec(scratch_list);                                    \
+        }                                                                  \
+    }                                                                      \
+    else {                                                                 \
+        /* For non-locale, just add it to any existing list */             \
+        _invlist_union(destlist,                                           \
+                       (AT_LEAST_ASCII_RESTRICTED)                         \
+                           ? sourcelist                                    \
+                           : Xsourcelist,                                  \
+                       &destlist);                                         \
+    }
+
+/* Like DO_POSIX, but matches the complement of <sourcelist> and <Xsourcelist>.
+ */
+#define DO_N_POSIX(node, class, destlist, sourcelist, Xsourcelist)         \
+    if (LOC) {                                                             \
+        SV* scratch_list = NULL;                                           \
+        ANYOF_CLASS_SET(node, class);                                     \
+        _invlist_subtract(PL_AboveLatin1, Xsourcelist, &scratch_list);    \
+        if (! destlist) {                                                 \
+            destlist = scratch_list;                                      \
+        }                                                                  \
+        else {                                                             \
+            _invlist_union(destlist, scratch_list, &destlist);             \
+            SvREFCNT_dec(scratch_list);                                    \
+        }                                                                  \
+    }                                                                      \
+    else {                                                                 \
+        _invlist_union_complement_2nd(destlist,                            \
+                                    (AT_LEAST_ASCII_RESTRICTED)            \
+                                        ? sourcelist                       \
+                                        : Xsourcelist,                     \
+                                    &destlist);                            \
+        /* Under /d, everything in the upper half of the Latin1 range      \
+         * matches this complement */                                      \
+        if (DEPENDS_SEMANTICS) {                                           \
+            ANYOF_FLAGS(node) |= ANYOF_NON_UTF8_LATIN1_ALL;                \
+        }                                                                  \
+    }
+
+/* Generate the code to add a posix character <class> to the bracketed
+ * character class given by <node>.  (<node> is needed only under locale rules)
+ * destlist       is the inversion list for non-locale rules that this class is
+ *                to be added to
+ * sourcelist     is the ASCII-range inversion list to add under /a rules
+ * l1_sourcelist  is the Latin1 range list to use otherwise.
+ * Xpropertyname  is the name to add to <run_time_list> of the property to
+ *                specify the code points above Latin1 that will have to be
+ *                determined at run-time
+ * run_time_list  is a SV* that contains text names of properties that are to
+ *                be computed at run time.  This concatenates <Xpropertyname>
+ *                to it, apppropriately
+ * This is essentially DO_POSIX, but we know only the Latin1 values at compile
+ * time */
+#define DO_POSIX_LATIN1_ONLY_KNOWN(node, class, destlist, sourcelist,      \
+                              l1_sourcelist, Xpropertyname, run_time_list) \
+    /* If not /a matching, there are going to be code points we will have  \
+     * to defer to runtime to look-up */                                   \
+    if (! AT_LEAST_ASCII_RESTRICTED) {                                     \
+        Perl_sv_catpvf(aTHX_ run_time_list, "+utf8::%s\n", Xpropertyname); \
+    }                                                                      \
+    if (LOC) {                                                             \
+        ANYOF_CLASS_SET(node, class);                                      \
+    }                                                                      \
+    else {                                                                 \
+        _invlist_union(destlist,                                           \
+                       (AT_LEAST_ASCII_RESTRICTED)                         \
+                           ? sourcelist                                    \
+                           : l1_sourcelist,                                \
+                       &destlist);                                         \
+    }
+
+/* Like DO_POSIX_LATIN1_ONLY_KNOWN, but for the complement.  A combination of
+ * this and DO_N_POSIX */
+#define DO_N_POSIX_LATIN1_ONLY_KNOWN(node, class, destlist, sourcelist,    \
+                              l1_sourcelist, Xpropertyname, run_time_list) \
+    if (AT_LEAST_ASCII_RESTRICTED) {                                       \
+        _invlist_union_complement_2nd(destlist, sourcelist, &destlist);    \
+    }                                                                      \
+    else {                                                                 \
+        Perl_sv_catpvf(aTHX_ run_time_list, "!utf8::%s\n", Xpropertyname); \
+       if (LOC) {                                                         \
+           ANYOF_CLASS_SET(node, namedclass);                             \
+       }                                                                  \
+       else {                                                             \
+            SV* scratch_list = NULL;                                       \
+           _invlist_subtract(PL_Latin1, l1_sourcelist, &scratch_list);    \
+           if (! destlist) {                                              \
+               destlist = scratch_list;                                   \
+           }                                                              \
+           else {                                                         \
+               _invlist_union(destlist, scratch_list, &destlist);         \
+               SvREFCNT_dec(scratch_list);                                \
+           }                                                              \
+           if (DEPENDS_SEMANTICS) {                                       \
+               ANYOF_FLAGS(node) |= ANYOF_NON_UTF8_LATIN1_ALL;            \
+           }                                                              \
+       }                                                                  \
+    }
 
 STATIC U8
 S_set_regclass_bit_fold(pTHX_ RExC_state_t *pRExC_state, regnode* node, const U8 value, SV** invlist_ptr, AV** alternate_ptr)
@@ -10368,18 +10725,7 @@ parseit:
 
                         /* Invert if asking for the complement */
                         if (value == 'P') {
-
-                           /* Add to any existing list */
-                           if (! properties) {
-                               properties = invlist_clone(invlist);
-                               _invlist_invert(properties);
-                           }
-                           else {
-                               invlist = invlist_clone(invlist);
-                               _invlist_invert(invlist);
-                               _invlist_union(properties, invlist, &properties);
-                               SvREFCNT_dec(invlist);
-                           }
+                           _invlist_union_complement_2nd(properties, invlist, &properties);
 
                             /* The swash can't be used as-is, because we've
                             * inverted things; delay removing it to here after
@@ -10388,12 +10734,7 @@ parseit:
                             swash = NULL;
                         }
                         else {
-                           if (! properties) {
-                               properties = invlist_clone(invlist);
-                           }
-                           else {
-                               _invlist_union(properties, invlist, &properties);
-                           }
+                            _invlist_union(properties, invlist, &properties);
                        }
                    }
                    Safefree(name);
@@ -10537,85 +10878,211 @@ parseit:
            }
 
            if (!SIZE_ONLY) {
-               const char *what = NULL;
-               char yesno = 0;
 
                /* Possible truncation here but in some 64-bit environments
                 * the compiler gets heartburn about switch on 64-bit values.
                 * A similar issue a little earlier when switching on value.
                 * --jhi */
                switch ((I32)namedclass) {
-               
-               case _C_C_T_(ALNUMC, isALNUMC_L1, isALNUMC, "XPosixAlnum", "XPosixAlnum");
-               case _C_C_T_(ALPHA, isALPHA_L1, isALPHA, "XPosixAlpha", "XPosixAlpha");
-               case _C_C_T_(BLANK, isBLANK_L1, isBLANK, "XPosixBlank", "XPosixBlank");
-               case _C_C_T_(CNTRL, isCNTRL_L1, isCNTRL, "XPosixCntrl", "XPosixCntrl");
-               case _C_C_T_(GRAPH, isGRAPH_L1, isGRAPH, "XPosixGraph", "XPosixGraph");
-               case _C_C_T_(LOWER, isLOWER_L1, isLOWER, "XPosixLower", "__XPosixLower_i");
-               case _C_C_T_(PRINT, isPRINT_L1, isPRINT, "XPosixPrint", "XPosixPrint");
-               case _C_C_T_(PSXSPC, isPSXSPC_L1, isPSXSPC, "XPosixSpace", "XPosixSpace");
-               case _C_C_T_(PUNCT, isPUNCT_L1, isPUNCT, "XPosixPunct", "XPosixPunct");
-               case _C_C_T_(UPPER, isUPPER_L1, isUPPER, "XPosixUpper", "__XPosixUpper_i");
-                /* \s, \w match all unicode if utf8. */
-                case _C_C_T_(SPACE, isSPACE_L1, isSPACE, "SpacePerl", "SpacePerl");
-                case _C_C_T_(ALNUM, isWORDCHAR_L1, isALNUM, "Word", "Word");
-               case _C_C_T_(XDIGIT, isXDIGIT_L1, isXDIGIT, "XPosixXDigit", "XPosixXDigit");
-               case _C_C_T_NOLOC_(VERTWS, is_VERTWS_latin1(&value), "VertSpace");
-               case _C_C_T_NOLOC_(HORIZWS, is_HORIZWS_latin1(&value), "HorizSpace");
+
+               case ANYOF_ALNUMC: /* C's alnum, in contrast to \w */
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlnum, PL_L1PosixAlnum, "XPosixAlnum", listsv);
+                   break;
+               case ANYOF_NALNUMC:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlnum, PL_L1PosixAlnum, "XPosixAlnum", listsv);
+                   break;
+               case ANYOF_ALPHA:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlpha, PL_L1PosixAlpha, "XPosixAlpha", listsv);
+                   break;
+               case ANYOF_NALPHA:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixAlpha, PL_L1PosixAlpha, "XPosixAlpha", listsv);
+                   break;
                case ANYOF_ASCII:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_ASCII);
-                   else {
-                       for (value = 0; value < 128; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) ASCII_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);
+                   if (LOC) {
+                       ANYOF_CLASS_SET(ret, namedclass);
                    }
-                   yesno = '+';
-                   what = NULL;        /* Doesn't match outside ascii, so
-                                          don't want to add +utf8:: */
+                    else {
+                        _invlist_union(properties, PL_ASCII, &properties);
+                    }
                    break;
                case ANYOF_NASCII:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_NASCII);
-                   else {
-                       for (value = 128; value < 256; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) ASCII_TO_NATIVE(value), &l1_fold_invlist, &unicode_alternate);
+                   if (LOC) {
+                       ANYOF_CLASS_SET(ret, namedclass);
                    }
-                   ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;
-                   yesno = '!';
-                   what = "ASCII";
-                   break;              
+                    else {
+                        _invlist_union_complement_2nd(properties,
+                                                    PL_ASCII, &properties);
+                        if (DEPENDS_SEMANTICS) {
+                            ANYOF_FLAGS(ret) |= ANYOF_NON_UTF8_LATIN1_ALL;
+                        }
+                    }
+                   break;
+               case ANYOF_BLANK:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixBlank, PL_XPosixBlank);
+                   break;
+               case ANYOF_NBLANK:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixBlank, PL_XPosixBlank);
+                   break;
+               case ANYOF_CNTRL:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixCntrl, PL_XPosixCntrl);
+                   break;
+               case ANYOF_NCNTRL:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixCntrl, PL_XPosixCntrl);
+                   break;
                case ANYOF_DIGIT:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
+                   /* Ignore the compiler warning for this macro, planned to
+                    * be eliminated later */
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixDigit, PL_PosixDigit, "XPosixDigit", listsv);
+                   break;
+               case ANYOF_NDIGIT:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixDigit, PL_PosixDigit, "XPosixDigit", listsv);
+                   break;
+               case ANYOF_GRAPH:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixGraph, PL_L1PosixGraph, "XPosixGraph", listsv);
+                   break;
+               case ANYOF_NGRAPH:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixGraph, PL_L1PosixGraph, "XPosixGraph", listsv);
+                   break;
+               case ANYOF_HORIZWS:
+                   /* For these, we use the nonbitmap, as /d doesn't make a
+                    * difference in what these match.  There would be problems
+                    * if these characters had folds other than themselves, as
+                    * nonbitmap is subject to folding.  It turns out that \h
+                    * is just a synonym for XPosixBlank */
+                   _invlist_union(nonbitmap, PL_XPosixBlank, &nonbitmap);
+                   break;
+               case ANYOF_NHORIZWS:
+                    _invlist_union_complement_2nd(nonbitmap,
+                                                 PL_XPosixBlank, &nonbitmap);
+                   break;
+               case ANYOF_LOWER:
+               case ANYOF_NLOWER:
+                {   /* These require special handling, as they differ under
+                      folding, matching Cased there (which in the ASCII range
+                      is the same as Alpha */
+
+                   SV* ascii_source;
+                   SV* l1_source;
+                   const char *Xname;
+
+                   if (FOLD && ! LOC) {
+                       ascii_source = PL_PosixAlpha;
+                       l1_source = PL_L1Cased;
+                       Xname = "Cased";
+                   }
+                   else {
+                       ascii_source = PL_PosixLower;
+                       l1_source = PL_L1PosixLower;
+                       Xname = "XPosixLower";
+                   }
+                   if (namedclass == ANYOF_LOWER) {
+                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                                    ascii_source, l1_source, Xname, listsv);
+                   }
                    else {
-                       /* consecutive digits assumed */
-                       for (value = '0'; value <= '9'; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);
+                       DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass,
+                            properties, ascii_source, l1_source, Xname, listsv);
                    }
-                   yesno = '+';
-                   what = "Digit";
                    break;
-               case ANYOF_NDIGIT:
-                   if (LOC)
-                       ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
+               }
+               case ANYOF_PRINT:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPrint, PL_L1PosixPrint, "XPosixPrint", listsv);
+                   break;
+               case ANYOF_NPRINT:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPrint, PL_L1PosixPrint, "XPosixPrint", listsv);
+                   break;
+               case ANYOF_PUNCT:
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPunct, PL_L1PosixPunct, "XPosixPunct", listsv);
+                   break;
+               case ANYOF_NPUNCT:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                        PL_PosixPunct, PL_L1PosixPunct, "XPosixPunct", listsv);
+                   break;
+               case ANYOF_PSXSPC:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixSpace, PL_XPosixSpace);
+                   break;
+               case ANYOF_NPSXSPC:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixSpace, PL_XPosixSpace);
+                   break;
+               case ANYOF_SPACE:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PerlSpace, PL_XPerlSpace);
+                   break;
+               case ANYOF_NSPACE:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PerlSpace, PL_XPerlSpace);
+                   break;
+               case ANYOF_UPPER:   /* Same as LOWER, above */
+               case ANYOF_NUPPER:
+               {
+                   SV* ascii_source;
+                   SV* l1_source;
+                   const char *Xname;
+
+                   if (FOLD && ! LOC) {
+                       ascii_source = PL_PosixAlpha;
+                       l1_source = PL_L1Cased;
+                       Xname = "Cased";
+                   }
                    else {
-                       /* consecutive digits assumed */
-                       for (value = 0; value < '0'; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);
-                       for (value = '9' + 1; value < 256; value++)
-                           stored +=
-                              set_regclass_bit(pRExC_state, ret, (U8) value, &l1_fold_invlist, &unicode_alternate);
+                       ascii_source = PL_PosixUpper;
+                       l1_source = PL_L1PosixUpper;
+                       Xname = "XPosixUpper";
+                   }
+                   if (namedclass == ANYOF_UPPER) {
+                       DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                                    ascii_source, l1_source, Xname, listsv);
                    }
-                   yesno = '!';
-                   what = "Digit";
-                   if (AT_LEAST_ASCII_RESTRICTED ) {
-                       ANYOF_FLAGS(ret) |= ANYOF_UNICODE_ALL;
+                   else {
+                       DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass,
+                        properties, ascii_source, l1_source, Xname, listsv);
                    }
-                   break;              
+                   break;
+               }
+               case ANYOF_ALNUM:   /* Really is 'Word' */
+                   DO_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                            PL_PosixWord, PL_L1PosixWord, "XPosixWord", listsv);
+                   break;
+               case ANYOF_NALNUM:
+                   DO_N_POSIX_LATIN1_ONLY_KNOWN(ret, namedclass, properties,
+                            PL_PosixWord, PL_L1PosixWord, "XPosixWord", listsv);
+                   break;
+               case ANYOF_VERTWS:
+                   /* For these, we use the nonbitmap, as /d doesn't make a
+                    * difference in what these match.  There would be problems
+                    * if these characters had folds other than themselves, as
+                    * nonbitmap is subject to folding */
+                   _invlist_union(nonbitmap, PL_VertSpace, &nonbitmap);
+                   break;
+               case ANYOF_NVERTWS:
+                    _invlist_union_complement_2nd(nonbitmap,
+                                                    PL_VertSpace, &nonbitmap);
+                   break;
+               case ANYOF_XDIGIT:
+                    DO_POSIX(ret, namedclass, properties,
+                                            PL_PosixXDigit, PL_XPosixXDigit);
+                   break;
+               case ANYOF_NXDIGIT:
+                    DO_N_POSIX(ret, namedclass, properties,
+                                            PL_PosixXDigit, PL_XPosixXDigit);
+                   break;
                case ANYOF_MAX:
                    /* this is to handle \p and \P */
                    break;
@@ -10623,10 +11090,6 @@ parseit:
                    vFAIL("Invalid [::] class");
                    break;
                }
-               if (what && ! (AT_LEAST_ASCII_RESTRICTED)) {
-                   /* Strings such as "+utf8::isWord\n" */
-                   Perl_sv_catpvf(aTHX_ listsv, "%cutf8::%s\n", yesno, what);
-               }
 
                continue;
            }
@@ -10964,13 +11427,14 @@ parseit:
            }
        }
 
-       /* Done with loop; set <nonbitmap> to not include any code points that
-        * are in the bitmap */
+        /* Done with loop; remove any code points that are in the bitmap from
+         * <nonbitmap> */
        if (change_invlist) {
-           SV* keep_list = _new_invlist(2);
-           _append_range_to_invlist(keep_list, max_cp_to_set + 1, UV_MAX);
-           _invlist_intersection(nonbitmap, keep_list, &nonbitmap);
-           SvREFCNT_dec(keep_list);
+           _invlist_subtract(nonbitmap,
+                             (DEPENDS_SEMANTICS)
+                               ? PL_ASCII
+                               : PL_Latin1,
+                              &nonbitmap);
        }
 
        /* If have completely emptied it, remove it completely */
@@ -11057,6 +11521,12 @@ parseit:
             * there should not be overlap unless is /d rules. */
            _invlist_invert(nonbitmap);
 
+           /* Any swash can't be used as-is, because we've inverted things */
+           if (swash) {
+               SvREFCNT_dec(swash);
+               swash = NULL;
+           }
+
            for (i = 0; i < 256; ++i) {
                if (ANYOF_BITMAP_TEST(ret, i)) {
                    ANYOF_BITMAP_CLEAR(ret, i);
@@ -11084,10 +11554,7 @@ parseit:
            else {
                /* There is no overlap for non-/d, so just delete anything
                 * below 256 */
-               SV* keep_list = _new_invlist(2);
-               _append_range_to_invlist(keep_list, 256, UV_MAX);
-               _invlist_intersection(nonbitmap, keep_list, &nonbitmap);
-               SvREFCNT_dec(keep_list);
+               _invlist_intersection(nonbitmap, PL_AboveLatin1, &nonbitmap);
            }
        }
 
@@ -11269,7 +11736,6 @@ parseit:
     }
     return ret;
 }
-#undef _C_C_T_
 
 
 /* reg_skipcomment()
@@ -11640,9 +12106,11 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p, const regnode *val,
     for (;;) {
         regnode * const temp = regnext(scan);
 #ifdef EXPERIMENTAL_INPLACESCAN
-        if (PL_regkind[OP(scan)] == EXACT)
-            if (join_exact(pRExC_state,scan,&min,1,val,depth+1))
+        if (PL_regkind[OP(scan)] == EXACT) {
+           bool has_exactf_sharp_s;    /* Unexamined in this routine */
+            if (join_exact(pRExC_state,scan,&min, &has_exactf_sharp_s, 1,val,depth+1))
                 return EXACT;
+       }
 #endif
         if ( exact ) {
             switch (OP(scan)) {
@@ -11651,7 +12119,7 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p, const regnode *val,
                 case EXACTFA:
                 case EXACTFU:
                 case EXACTFU_SS:
-                case EXACTFU_NO_TRIE:
+                case EXACTFU_TRICKYFOLD:
                 case EXACTFL:
                         if( exact == PSEUDO )
                             exact= OP(scan);
@@ -11976,8 +12444,6 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
                           SVfARG((MUTABLE_SV(progi->data->data[ ARG( o ) ]))));
     } else if (k == LOGICAL)
        Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
-    else if (k == FOLDCHAR)
-       Perl_sv_catpvf(aTHX_ sv, "[0x%"UVXf"]", PTR2UV(ARG(o)) );
     else if (k == ANYOF) {
        int i, rangestart = -1;
        const U8 flags = ANYOF_FLAGS(o);