Omnibus removal of register declarations

This removes most register declarations in C code (and accompanying
documentation) in the Perl core.  Retained are those in the ext
directory, Configure, and those that are associated with assembly
language.

See:
http://stackoverflow.com/questions/314994/whats-a-good-example-of-register-variable-usage-in-c

which says, in part:

There is no good example of register usage when using modern compilers
(read: last 10+ years) because it almost never does any good and can do
some bad. When you use register, you are telling the compiler "I know
how to optimize my code better than you do" which is almost never the
case. One of three things can happen when you use register:

    The compiler ignores it, this is most likely. In this case the only
        harm is that you cannot take the address of the variable in the
        code.
    The compiler honors your request and as a result the code runs slower.
    The compiler honors your request and the code runs faster, this is the least likely scenario.

Even if one compiler produces better code when you use register, there
is no reason to believe another will do the same. If you have some
critical code that the compiler is not optimizing well enough your best
bet is probably to use assembler for that part anyway but of course do
the appropriate profiling to verify the generated code is really a
problem first.

1 files changed, 39 insertions, 39 deletions

diff --git a/pp_sys.c b/pp_sys.c
index 85fa25174b..b233942287 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -669,8 +669,8 @@ PP(pp_pipe_op)
 #ifdef HAS_PIPE
     dVAR;
     dSP;
-    register IO *rstio;
-    register IO *wstio;
+    IO *rstio;
+    IO *wstio;
     int fd[2];
 
     GV * const wgv = MUTABLE_GV(POPs);
@@ -1059,10 +1059,10 @@ PP(pp_sselect)
 {
 #ifdef HAS_SELECT
     dVAR; dSP; dTARGET;
-    register I32 i;
-    register I32 j;
-    register char *s;
-    register SV *sv;
+    I32 i;
+    I32 j;
+    char *s;
+    SV *sv;
     NV value;
     I32 maxlen = 0;
     I32 nfound;
@@ -1322,7 +1322,7 @@ STATIC OP *
 S_doform(pTHX_ CV *cv, GV *gv, OP *retop)
 {
     dVAR;
-    register PERL_CONTEXT *cx;
+    PERL_CONTEXT *cx;
     const I32 gimme = GIMME_V;
 
     PERL_ARGS_ASSERT_DOFORM;
@@ -1350,8 +1350,8 @@ PP(pp_enterwrite)
 {
     dVAR;
     dSP;
-    register GV *gv;
-    register IO *io;
+    GV *gv;
+    IO *io;
     GV *fgv;
     CV *cv = NULL;
     SV *tmpsv = NULL;
@@ -1390,12 +1390,12 @@ PP(pp_leavewrite)
 {
     dVAR; dSP;
     GV * const gv = cxstack[cxstack_ix].blk_format.gv;
-    register IO * const io = GvIOp(gv);
+    IO * const io = GvIOp(gv);
     PerlIO *ofp;
     PerlIO *fp;
     SV **newsp;
     I32 gimme;
-    register PERL_CONTEXT *cx;
+    PERL_CONTEXT *cx;
     OP *retop;
 
     if (!io || !(ofp = IoOFP(io)))
@@ -2380,7 +2380,7 @@ PP(pp_socket)
     const int type = POPi;
     const int domain = POPi;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = gv ? GvIOn(gv) : NULL;
+    IO * const io = gv ? GvIOn(gv) : NULL;
     int fd;
 
     if (!io) {
@@ -2428,8 +2428,8 @@ PP(pp_sockpair)
     const int domain = POPi;
     GV * const gv2 = MUTABLE_GV(POPs);
     GV * const gv1 = MUTABLE_GV(POPs);
-    register IO * const io1 = gv1 ? GvIOn(gv1) : NULL;
-    register IO * const io2 = gv2 ? GvIOn(gv2) : NULL;
+    IO * const io1 = gv1 ? GvIOn(gv1) : NULL;
+    IO * const io2 = gv2 ? GvIOn(gv2) : NULL;
     int fd[2];
 
     if (!io1)
@@ -2483,7 +2483,7 @@ PP(pp_bind)
     /* OK, so on what platform does bind modify addr?  */
     const char *addr;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
     STRLEN len;
     const int op_type = PL_op->op_type;
 
@@ -2511,7 +2511,7 @@ PP(pp_listen)
     dVAR; dSP;
     const int backlog = POPi;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = gv ? GvIOn(gv) : NULL;
+    IO * const io = gv ? GvIOn(gv) : NULL;
 
     if (!io || !IoIFP(io))
 	goto nuts;
@@ -2530,8 +2530,8 @@ nuts:
 PP(pp_accept)
 {
     dVAR; dSP; dTARGET;
-    register IO *nstio;
-    register IO *gstio;
+    IO *nstio;
+    IO *gstio;
     char namebuf[MAXPATHLEN];
 #if (defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)) || defined(MPE) || defined(__QNXNTO__)
     Sock_size_t len = sizeof (struct sockaddr_in);
@@ -2606,7 +2606,7 @@ PP(pp_shutdown)
     dVAR; dSP; dTARGET;
     const int how = POPi;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
 
     if (!io || !IoIFP(io))
 	goto nuts;
@@ -2628,7 +2628,7 @@ PP(pp_ssockopt)
     const unsigned int optname = (unsigned int) POPi;
     const unsigned int lvl = (unsigned int) POPi;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
     int fd;
     Sock_size_t len;
 
@@ -2697,7 +2697,7 @@ PP(pp_getpeername)
     dVAR; dSP;
     const int optype = PL_op->op_type;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
     Sock_size_t len;
     SV *sv;
     int fd;
@@ -3307,9 +3307,9 @@ PP(pp_fttext)
     I32 len;
     I32 odd = 0;
     STDCHAR tbuf[512];
-    register STDCHAR *s;
-    register IO *io;
-    register SV *sv = NULL;
+    STDCHAR *s;
+    IO *io;
+    SV *sv = NULL;
     GV *gv;
     PerlIO *fp;
 
@@ -3820,7 +3820,7 @@ PP(pp_open_dir)
     dVAR; dSP;
     const char * const dirname = POPpconstx;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
 
     if (!io)
 	goto nope;
@@ -3858,8 +3858,8 @@ PP(pp_readdir)
     SV *sv;
     const I32 gimme = GIMME;
     GV * const gv = MUTABLE_GV(POPs);
-    register const Direntry_t *dp;
-    register IO * const io = GvIOn(gv);
+    const Direntry_t *dp;
+    IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io)) {
 	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
@@ -3911,7 +3911,7 @@ PP(pp_telldir)
     long telldir (DIR *);
 # endif
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io)) {
 	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
@@ -3937,7 +3937,7 @@ PP(pp_seekdir)
     dVAR; dSP;
     const long along = POPl;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io)) {
 	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
@@ -3962,7 +3962,7 @@ PP(pp_rewinddir)
 #if defined(HAS_REWINDDIR) || defined(rewinddir)
     dVAR; dSP;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io)) {
 	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
@@ -3986,7 +3986,7 @@ PP(pp_closedir)
 #if defined(Direntry_t) && defined(HAS_READDIR)
     dVAR; dSP;
     GV * const gv = MUTABLE_GV(POPs);
-    register IO * const io = GvIOn(gv);
+    IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io)) {
 	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
@@ -4722,8 +4722,8 @@ PP(pp_ghostent)
 #if defined(HAS_GETHOSTBYNAME) || defined(HAS_GETHOSTBYADDR) || defined(HAS_GETHOSTENT)
     dVAR; dSP;
     I32 which = PL_op->op_type;
-    register char **elem;
-    register SV *sv;
+    char **elem;
+    SV *sv;
 #ifndef HAS_GETHOST_PROTOS /* XXX Do we need individual probes? */
     struct hostent *gethostbyaddr(Netdb_host_t, Netdb_hlen_t, int);
     struct hostent *gethostbyname(Netdb_name_t);
@@ -4812,7 +4812,7 @@ PP(pp_gnetent)
 #if defined(HAS_GETNETBYNAME) || defined(HAS_GETNETBYADDR) || defined(HAS_GETNETENT)
     dVAR; dSP;
     I32 which = PL_op->op_type;
-    register SV *sv;
+    SV *sv;
 #ifndef HAS_GETNET_PROTOS /* XXX Do we need individual probes? */
     struct netent *getnetbyaddr(Netdb_net_t, int);
     struct netent *getnetbyname(Netdb_name_t);
@@ -4885,7 +4885,7 @@ PP(pp_gprotoent)
 #if defined(HAS_GETPROTOBYNAME) || defined(HAS_GETPROTOBYNUMBER) || defined(HAS_GETPROTOENT)
     dVAR; dSP;
     I32 which = PL_op->op_type;
-    register SV *sv;
+    SV *sv;
 #ifndef HAS_GETPROTO_PROTOS /* XXX Do we need individual probes? */
     struct protoent *getprotobyname(Netdb_name_t);
     struct protoent *getprotobynumber(int);
@@ -4945,7 +4945,7 @@ PP(pp_gservent)
 #if defined(HAS_GETSERVBYNAME) || defined(HAS_GETSERVBYPORT) || defined(HAS_GETSERVENT)
     dVAR; dSP;
     I32 which = PL_op->op_type;
-    register SV *sv;
+    SV *sv;
 #ifndef HAS_GETSERV_PROTOS /* XXX Do we need individual probes? */
     struct servent *getservbyname(Netdb_name_t, Netdb_name_t);
     struct servent *getservbyport(int, Netdb_name_t);
@@ -5122,7 +5122,7 @@ PP(pp_gpwent)
 #ifdef HAS_PASSWD
     dVAR; dSP;
     I32 which = PL_op->op_type;
-    register SV *sv;
+    SV *sv;
     struct passwd *pwent  = NULL;
     /*
      * We currently support only the SysV getsp* shadow password interface.
@@ -5446,9 +5446,9 @@ PP(pp_syscall)
 {
 #ifdef HAS_SYSCALL
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    register I32 items = SP - MARK;
+    I32 items = SP - MARK;
     unsigned long a[20];
-    register I32 i = 0;
+    I32 i = 0;
     IV retval = -1;
 
     if (PL_tainting) {