Add SORTf_UNSTABLE flag

This will allow a future commit to make mergesort unstable when
the user specifies ‘no sort stable’, since it has been decided
that mergesort should remain stable by default.

This bit is not yet used, but is quite harmless.

1 files changed, 70 insertions, 68 deletions

diff --git a/opcode.h b/opcode.h
index bd8de366e5..943daa5939 100644
--- a/opcode.h
+++ b/opcode.h
@@ -2299,6 +2299,7 @@ END_EXTERN_C
 #define OPpOFFBYONE             0x80
 #define OPpOPEN_OUT_CRLF        0x80
 #define OPpPV_IS_UTF8           0x80
+#define OPpSORT_UNSTABLE        0x80
 #define OPpTRANS_DELETE         0x80
 START_EXTERN_C
 
@@ -2412,6 +2413,7 @@ EXTCONST char PL_op_private_labels[] = {
     'T','A','R','G','\0',
     'T','A','R','G','M','Y','\0',
     'U','N','I','\0',
+    'U','N','S','T','A','B','L','E','\0',
     'U','T','F','\0',
     'k','e','y','\0',
     'o','f','f','s','e','t','\0',
@@ -2434,11 +2436,11 @@ EXTCONST char PL_op_private_labels[] = {
 EXTCONST I16 PL_op_private_bitfields[] = {
     0, 8, -1,
     0, 8, -1,
-    0, 556, -1,
+    0, 565, -1,
     0, 8, -1,
     0, 8, -1,
-    0, 563, -1,
-    0, 552, -1,
+    0, 572, -1,
+    0, 561, -1,
     1, -1, 0, 529, 1, 33, 2, 283, -1,
     4, -1, 1, 164, 2, 171, 3, 178, -1,
     4, -1, 0, 529, 1, 33, 2, 283, 3, 110, -1,
@@ -2617,49 +2619,49 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
        0, /* shift */
       84, /* unshift */
      143, /* sort */
-     150, /* reverse */
+     151, /* reverse */
        0, /* grepstart */
-     152, /* grepwhile */
+     153, /* grepwhile */
        0, /* mapstart */
        0, /* mapwhile */
        0, /* range */
-     154, /* flip */
-     154, /* flop */
+     155, /* flip */
+     155, /* flop */
        0, /* and */
        0, /* or */
       12, /* xor */
        0, /* dor */
-     156, /* cond_expr */
+     157, /* cond_expr */
        0, /* andassign */
        0, /* orassign */
        0, /* dorassign */
-     158, /* entersub */
-     165, /* leavesub */
-     165, /* leavesublv */
+     159, /* entersub */
+     166, /* leavesub */
+     166, /* leavesublv */
        0, /* argcheck */
-     167, /* argelem */
+     168, /* argelem */
        0, /* argdefelem */
-     169, /* caller */
+     170, /* caller */
       52, /* warn */
       52, /* die */
       52, /* reset */
       -1, /* lineseq */
-     171, /* nextstate */
-     171, /* dbstate */
+     172, /* nextstate */
+     172, /* dbstate */
       -1, /* unstack */
       -1, /* enter */
-     172, /* leave */
+     173, /* leave */
       -1, /* scope */
-     174, /* enteriter */
-     178, /* iter */
+     175, /* enteriter */
+     179, /* iter */
       -1, /* enterloop */
-     179, /* leaveloop */
+     180, /* leaveloop */
       -1, /* return */
-     181, /* last */
-     181, /* next */
-     181, /* redo */
-     181, /* dump */
-     181, /* goto */
+     182, /* last */
+     182, /* next */
+     182, /* redo */
+     182, /* dump */
+     182, /* goto */
       52, /* exit */
        0, /* method */
        0, /* method_named */
@@ -2672,7 +2674,7 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
        0, /* leavewhen */
       -1, /* break */
       -1, /* continue */
-     183, /* open */
+     184, /* open */
       52, /* close */
       52, /* pipe_op */
       52, /* fileno */
@@ -2688,7 +2690,7 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
       52, /* getc */
       52, /* read */
       52, /* enterwrite */
-     165, /* leavewrite */
+     166, /* leavewrite */
       -1, /* prtf */
       -1, /* print */
       -1, /* say */
@@ -2718,33 +2720,33 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
        0, /* getpeername */
        0, /* lstat */
        0, /* stat */
-     188, /* ftrread */
-     188, /* ftrwrite */
-     188, /* ftrexec */
-     188, /* fteread */
-     188, /* ftewrite */
-     188, /* fteexec */
-     193, /* ftis */
-     193, /* ftsize */
-     193, /* ftmtime */
-     193, /* ftatime */
-     193, /* ftctime */
-     193, /* ftrowned */
-     193, /* fteowned */
-     193, /* ftzero */
-     193, /* ftsock */
-     193, /* ftchr */
-     193, /* ftblk */
-     193, /* ftfile */
-     193, /* ftdir */
-     193, /* ftpipe */
-     193, /* ftsuid */
-     193, /* ftsgid */
-     193, /* ftsvtx */
-     193, /* ftlink */
-     193, /* fttty */
-     193, /* fttext */
-     193, /* ftbinary */
+     189, /* ftrread */
+     189, /* ftrwrite */
+     189, /* ftrexec */
+     189, /* fteread */
+     189, /* ftewrite */
+     189, /* fteexec */
+     194, /* ftis */
+     194, /* ftsize */
+     194, /* ftmtime */
+     194, /* ftatime */
+     194, /* ftctime */
+     194, /* ftrowned */
+     194, /* fteowned */
+     194, /* ftzero */
+     194, /* ftsock */
+     194, /* ftchr */
+     194, /* ftblk */
+     194, /* ftfile */
+     194, /* ftdir */
+     194, /* ftpipe */
+     194, /* ftsuid */
+     194, /* ftsgid */
+     194, /* ftsvtx */
+     194, /* ftlink */
+     194, /* fttty */
+     194, /* fttext */
+     194, /* ftbinary */
       84, /* chdir */
       84, /* chown */
       75, /* chroot */
@@ -2764,17 +2766,17 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
        0, /* rewinddir */
        0, /* closedir */
       -1, /* fork */
-     197, /* wait */
+     198, /* wait */
       84, /* waitpid */
       84, /* system */
       84, /* exec */
       84, /* kill */
-     197, /* getppid */
+     198, /* getppid */
       84, /* getpgrp */
       84, /* setpgrp */
       84, /* getpriority */
       84, /* setpriority */
-     197, /* time */
+     198, /* time */
       -1, /* tms */
        0, /* localtime */
       52, /* gmtime */
@@ -2794,8 +2796,8 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
        0, /* require */
        0, /* dofile */
       -1, /* hintseval */
-     198, /* entereval */
-     165, /* leaveeval */
+     199, /* entereval */
+     166, /* leaveeval */
        0, /* entertry */
       -1, /* leavetry */
        0, /* ghbyname */
@@ -2833,18 +2835,18 @@ EXTCONST I16  PL_op_private_bitdef_ix[] = {
        0, /* lock */
        0, /* once */
       -1, /* custom */
-     204, /* coreargs */
-     208, /* avhvswitch */
+     205, /* coreargs */
+     209, /* avhvswitch */
        3, /* runcv */
        0, /* fc */
       -1, /* padcv */
       -1, /* introcv */
       -1, /* clonecv */
-     210, /* padrange */
-     212, /* refassign */
-     218, /* lvref */
-     224, /* lvrefslice */
-     225, /* lvavref */
+     211, /* padrange */
+     213, /* refassign */
+     219, /* lvref */
+     225, /* lvrefslice */
+     226, /* lvavref */
        0, /* anonconst */
 
 };
@@ -2905,7 +2907,7 @@ EXTCONST U16  PL_op_private_bitdefs[] = {
     0x2e5c, 0x2d58, 0x1074, 0x19d0, 0x2f4c, 0x40c4, 0x0003, /* multideref */
     0x2e5c, 0x33f8, 0x0350, 0x2b6c, 0x2489, /* split */
     0x2e5c, 0x20f9, /* list */
-    0x3f38, 0x3694, 0x1310, 0x27ac, 0x39e8, 0x28a4, 0x3361, /* sort */
+    0x449c, 0x3f38, 0x3694, 0x1310, 0x27ac, 0x39e8, 0x28a4, 0x3361, /* sort */
     0x27ac, 0x0003, /* reverse */
     0x0614, 0x0003, /* grepwhile */
     0x2bf8, 0x0003, /* flip, flop */
@@ -2919,7 +2921,7 @@ EXTCONST U16  PL_op_private_bitdefs[] = {
     0x2e5c, 0x33f8, 0x0f6c, 0x3a65, /* enteriter */
     0x3a65, /* iter */
     0x2cfc, 0x0067, /* leaveloop */
-    0x449c, 0x0003, /* last, next, redo, dump, goto */
+    0x45bc, 0x0003, /* last, next, redo, dump, goto */
     0x35dc, 0x34f8, 0x2714, 0x2650, 0x018f, /* open */
     0x1c70, 0x1ecc, 0x1d88, 0x1b44, 0x0003, /* ftrread, ftrwrite, ftrexec, fteread, ftewrite, fteexec */
     0x1c70, 0x1ecc, 0x1d88, 0x0003, /* ftis, ftsize, ftmtime, ftatime, ftctime, ftrowned, fteowned, ftzero, ftsock, ftchr, ftblk, ftfile, ftdir, ftpipe, ftsuid, ftsgid, ftsvtx, ftlink, fttty, fttext, ftbinary */
@@ -3106,7 +3108,7 @@ EXTCONST U8 PL_op_private_valid[] = {
     /* POP        */ (OPpARG1_MASK),
     /* SHIFT      */ (OPpARG1_MASK),
     /* UNSHIFT    */ (OPpARG4_MASK|OPpTARGET_MY),
-    /* SORT       */ (OPpSORT_NUMERIC|OPpSORT_INTEGER|OPpSORT_REVERSE|OPpSORT_INPLACE|OPpSORT_DESCEND|OPpSORT_QSORT|OPpSORT_STABLE),
+    /* SORT       */ (OPpSORT_NUMERIC|OPpSORT_INTEGER|OPpSORT_REVERSE|OPpSORT_INPLACE|OPpSORT_DESCEND|OPpSORT_QSORT|OPpSORT_STABLE|OPpSORT_UNSTABLE),
     /* REVERSE    */ (OPpARG1_MASK|OPpREVERSE_INPLACE),
     /* GREPSTART  */ (OPpARG1_MASK),
     /* GREPWHILE  */ (OPpARG1_MASK|OPpTRUEBOOL),