[hackers] [scc] Simplify expression like *& or &* || Roberto E. Vargas Caballero

[git]

commit 79ccb978a8d4f8c9c9700bb16d2b97625f3f1dd4
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Wed Aug 26 22:25:35 2015 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Wed Aug 26 22:25:35 2015 +0200

    Simplify expression like *& or &*
    
    This kind of expressions are common in array expressions
    and the can simplify a lot the IR generated.

diff --git a/cc1/expr.c b/cc1/expr.c
index 7414c00..5f22825 100644
--- a/cc1/expr.c
+++ b/cc1/expr.c
@@ -358,6 +358,12 @@ decay(Node *np)
        switch (tp->op) {
        case ARY:
                tp = tp->type;
+               if (np->op == OPTR) {
+                       Node *new = np->left;
+                       free(np);
+                       new->type = mktype(tp, PTR, 0, NULL);
+                       return new;
+               }
        case FTN:
                break;
        default:
@@ -539,14 +545,16 @@ parithmetic(char op, Node *lp, Node *rp)
        }
        if (BTYPE(rp) != INT)
                goto incorrect;
+
        rp = convert(promote(rp), sizettype, 0);
-       rp = node(OMUL, sizettype, rp, size);
-       rp = node(OCAST, tp, rp, NULL);
+       rp = simplify(OMUL, sizettype, rp, size);
+       rp = convert(rp, tp, 1);
 
-       return node(OADD, tp, lp, rp);
+       return simplify(OADD, tp, lp, rp);
 
 incorrect:
-       error("incorrect arithmetic operands");
+       errorp("incorrect arithmetic operands");
+       return node(OADD, tp, lp, rp);
 }
 
 static Node *
@@ -752,6 +760,11 @@ address(char op, Node *np)
                error("lvalue required in unary expression");
        if (np->symbol && (np->sym->flags & ISREGISTER))
                error("address of register variable '%s' requested", yytext);
+       if (np->op == OPTR) {
+               Node *new = np->left;
+               free(np);
+               return new;
+       }
        return node(op, mktype(np->type, PTR, 0, NULL), np, NULL);
 }
 
@@ -761,8 +774,12 @@ content(char op, Node *np)
        switch (BTYPE(np)) {
        case ARY:
        case FTN:
-               np = decay(np);
        case PTR:
+               if (np->op == OADDR) {
+                       Node *new = np->left;
+                       free(np);
+                       return new;
+               }
                np = node(op, np->type->type, np, NULL);
                np->lvalue = 1;
                return np;