Generate smaller object code by using a single switch statement

for determining which names are forced into main::

p4raw-id: //depot/perl@23718

diff --git a/gv.c b/gv.c
index d2b885d..8fb7fba 100644 (file)
--- a/gv.c
+++ b/gv.c
@@ -720,24 +720,31 @@ Perl_gv_fetchpv(pTHX_ const char *nambeg, I32 add, I32 sv_type)
        if (isIDFIRST_lazy(name)) {
            bool global = FALSE;
 
-           if (isUPPER(*name)) {
-               if (*name == 'S' && (
-                   strEQ(name, "SIG") ||
-                   strEQ(name, "STDIN") ||
-                   strEQ(name, "STDOUT") ||
-                   strEQ(name, "STDERR")))
+           /* name is always \0 terminated, and initial \0 wouldn't return
+              true from isIDFIRST_lazy, so we know that name[1] is defined  */
+           switch (name[1]) {
+           case '\0':
+               if (*name == '_')
                    global = TRUE;
-               else if (*name == 'I' && strEQ(name, "INC"))
+               break;
+           case 'N':
+               if (strEQ(name, "INC") || strEQ(name, "ENV"))
                    global = TRUE;
-               else if (*name == 'E' && strEQ(name, "ENV"))
+               break;
+           case 'I':
+               if (strEQ(name, "SIG"))
                    global = TRUE;
-               else if (*name == 'A' && (
-                 strEQ(name, "ARGV") ||
-                 strEQ(name, "ARGVOUT")))
+               break;
+           case 'T':
+               if (strEQ(name, "STDIN") || strEQ(name, "STDOUT") ||
+                   strEQ(name, "STDERR"))
                    global = TRUE;
+               break;
+           case 'R':
+               if (strEQ(name, "ARGV") || strEQ(name, "ARGVOUT"))
+                   global = TRUE;
+               break;
            }
-           else if (*name == '_' && !name[1])
-               global = TRUE;
 
            if (global)
                stash = PL_defstash;