[hackers] [scc] Fix simplification of comparision nodes || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Sun, 26 Jul 2015 19:56:54 +0200 (CEST)

commit dac8c31a33977081e510992580a5e47c2d3ffe84
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Sun Jul 26 19:54:41 2015 +0200
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Sun Jul 26 19:54:41 2015 +0200

    Fix simplification of comparision nodes
    
    Comparision nodes have integer type, but the operands cn have
    a different type, so we cannot take the decision based in the
    type parameter of simplify().

diff --git a/cc1/cc1.h b/cc1/cc1.h
index 385797a..8da3585 100644
--- a/cc1/cc1.h
+++ b/cc1/cc1.h
_AT_@ -335,6 +335,7 @@ extern Node *usimplify(unsigned char op, Type *tp, Node *np);
 extern Node *expr(void), *negate(Node *np), *constexpr(void);
 extern Node *convert(Node *np, Type *tp1, char iscast);
 extern Node *iszero(Node *np), *eval(Node *np), *iconstexpr(void);
+extern bool isnodecmp(int op);
 
 /* cpp.c */
 extern void icpp(void);
diff --git a/cc1/code.c b/cc1/code.c
index e982b99..e8ed265 100644
--- a/cc1/code.c
+++ b/cc1/code.c
_AT_@ -391,6 +391,9 @@ sizeofnode(Type *tp)
         ((sym)->u.i = ((ls)->u.i op (rs)->u.i)) : \
         ((sym)->u.u = ((ls)->u.u op (rs)->u.u)))
 
+#define CMPISYM(sym, ls, rs, op) (((sym)->type->sign) ? \
+ ((ls)->u.i op (rs)->u.i) : ((ls)->u.u op (rs)->u.u))
+
 Node *
 simplify(unsigned char op, Type *tp, Node *lp, Node *rp)
 {
_AT_@ -403,8 +406,22 @@ simplify(unsigned char op, Type *tp, Node *lp, Node *rp)
 
         /* TODO: Add overflow checkings */
 
+ if (isnodecmp(op)) {
+ /*
+ * Comparision nodes have integer type
+ * but the operands can have different
+ * type.
+ */
+ switch (BTYPE(lp)) {
+ case INT: goto cmp_integers;
+ case FLOAT: goto cmp_floats;
+ default: goto no_simplify;
+ }
+ }
+
         switch (tp->op) {
         case INT:
+ cmp_integers:
                 switch (op) {
                 case OADD:
                         FOLDINT(&aux, ls, rs, +);
_AT_@ -431,29 +448,6 @@ simplify(unsigned char op, Type *tp, Node *lp, Node *rp)
                 case OSHR:
                         FOLDINT(&aux, ls, rs, >>);
                         break;
- /*
- * FIXME: comparision nodes are integers
- * but it doesn't mean the operands are
- * integers too
- */
- case OLT:
- FOLDINT(&aux, ls, rs, <);
- break;
- case OGT:
- FOLDINT(&aux, ls, rs, >);
- break;
- case OGE:
- FOLDINT(&aux, ls, rs, >=);
- break;
- case OLE:
- FOLDINT(&aux, ls, rs, <=);
- break;
- case OEQ:
- FOLDINT(&aux, ls, rs, ==);
- break;
- case ONE:
- FOLDINT(&aux, ls, rs, !=);
- break;
                 case OBAND:
                         FOLDINT(&aux, ls, rs, &);
                         break;
_AT_@ -469,9 +463,28 @@ simplify(unsigned char op, Type *tp, Node *lp, Node *rp)
                 case OOR:
                         FOLDINT(&aux, ls, rs, ||);
                         break;
+ case OLT:
+ aux.u.i = CMPISYM(&aux, ls, rs, <);
+ break;
+ case OGT:
+ aux.u.i = CMPISYM(&aux, ls, rs, >);
+ break;
+ case OGE:
+ aux.u.i = CMPISYM(&aux, ls, rs, >=);
+ break;
+ case OLE:
+ aux.u.i = CMPISYM(&aux, ls, rs, <=);
+ break;
+ case OEQ:
+ aux.u.i = CMPISYM(&aux, ls, rs, ==);
+ break;
+ case ONE:
+ aux.u.i = CMPISYM(&aux, ls, rs, !=);
+ break;
                 }
                 break;
         case FLOAT:
+ cmp_floats:
                 switch (op) {
                 case OADD:
                         aux.u.f = ls->u.f + rs->u.f;
_AT_@ -487,6 +500,24 @@ simplify(unsigned char op, Type *tp, Node *lp, Node *rp)
                                 goto division_by_0;
                         aux.u.f = ls->u.f / rs->u.f;
                         break;
+ case OLT:
+ aux.u.i = ls->u.f < rs->u.f;
+ break;
+ case OGT:
+ aux.u.i = ls->u.f > rs->u.f;
+ break;
+ case OGE:
+ aux.u.i = ls->u.f >= rs->u.f;
+ break;
+ case OLE:
+ aux.u.i = ls->u.f <= rs->u.f;
+ break;
+ case OEQ:
+ aux.u.i = ls->u.f == rs->u.f;
+ break;
+ case ONE:
+ aux.u.i = ls->u.f != rs->u.f;
+ break;
                 }
                 break;
         default:
diff --git a/cc1/expr.c b/cc1/expr.c
index 7ae3666..e0ab3d3 100644
--- a/cc1/expr.c
+++ b/cc1/expr.c
_AT_@ -303,10 +303,10 @@ negate(Node *np)
         return np;
 }
 
-static bool
-isnodecmp(Node *np)
+bool
+isnodecmp(int op)
 {
- switch (np->op) {
+ switch (op) {
         case OEQ:
         case ONE:
         case OLT:
_AT_@ -322,7 +322,7 @@ isnodecmp(Node *np)
 static Node *
 exp2cond(Node *np, char neg)
 {
- if (isnodecmp(np))
+ if (isnodecmp(np->op))
                 return (neg) ? negate(np) : np;
         return compare(ONE ^ neg, np, constnode(zero));
 }
_AT_@ -374,7 +374,7 @@ array(Node *lp, Node *rp)
 Node *
 iszero(Node *np)
 {
- if (isnodecmp(np))
+ if (isnodecmp(np->op))
                 return np;
         return compare(ONE, np, constnode(zero));
 }
Received on Sun Jul 26 2015 - 19:56:54 CEST