[hackers] [scc] Avoid doble call to hash() in lookup() || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Fri, 21 Aug 2015 13:10:37 +0200 (CEST)

X-DEBUG-UPD: ac748964eb6c3535320d3bedc211a4e272cf946f
commit ac748964eb6c3535320d3bedc211a4e272cf946f
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Tue Aug 18 14:24:12 2015 +0200
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Tue Aug 18 14:24:12 2015 +0200

    Avoid doble call to hash() in lookup()
    
    It is better to pass the hash value to linkhash
    instead of calling to lookup all the times inside
    of linkhash().

diff --git a/cc1/symbol.c b/cc1/symbol.c
index 5738d2e..e2e7e0f 100644
--- a/cc1/symbol.c
+++ b/cc1/symbol.c
_AT_@ -55,12 +55,12 @@ hash(const char *s)
 }
 
 static Symbol *
-linkhash(Symbol *sym, char *name)
+linkhash(Symbol *sym, char *name, unsigned hval)
 {
         Symbol **h, *p, *prev;
 
         sym->name = xstrdup(name);
- h = &htab[hash(name)];
+ h = &htab[hval];
 
         for (prev = p = *h; p; prev = p, p = p->hash) {
                 if (p->ctx <= sym->ctx)
_AT_@ -204,10 +204,11 @@ Symbol *
 lookup(unsigned ns)
 {
         Symbol *sym, **h;
- unsigned sns;
+ unsigned sns, v;
         char *t, c;
 
- h = &htab[hash(yytext)];
+ v = hash(yytext);
+ h = &htab[v];
         c = *yytext;
         for (sym = *h; sym; sym = sym->hash) {
                 t = sym->name;
_AT_@ -220,7 +221,7 @@ lookup(unsigned ns)
                         continue;
                 return sym;
         }
- sym = linkhash(newsym(ns), yytext);
+ sym = linkhash(newsym(ns), yytext, v);
         sym->flags &= ~ISDECLARED;
 
         return sym;
_AT_@ -254,7 +255,7 @@ nextsym(Symbol *sym, unsigned ns)
                 if (c == *t && !strcmp(s, t))
                         return sym;
         }
- new = linkhash(newsym(ns), s);
+ new = linkhash(newsym(ns), s, hash(s));
         new->flags &= ~ISDECLARED;
         return new;
 }
_AT_@ -272,7 +273,7 @@ install(unsigned ns, Symbol *sym)
                         goto assign_id;
                 }
         }
- sym = linkhash(newsym(ns), sym->name);
+ sym = linkhash(newsym(ns), sym->name, hash(sym->name));
 
 assign_id:
         if (sym->ns != NS_CPP || sym->ns != NS_LABEL)
Received on Fri Aug 21 2015 - 13:10:37 CEST