[Bug optimization/14303] [tree-ssa] gcc.c-torture/execute/20020720-1.c is not fully folded

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-02-29 01:49 -------
I would propose something along the lines of this if I knew when this 
transformation is valid/safe... 
 
Index: fold-const.c 
=================================================================== 
RCS file: /cvs/gcc/gcc/gcc/fold-const.c,v 
retrieving revision 1.213.2.75 
diff -c -3 -p -r1.213.2.75 fold-const.c 
*** fold-const.c        27 Feb 2004 21:50:48 -0000      1.213.2.75 
--- fold-const.c        29 Feb 2004 01:44:44 -0000 
*************** fold (tree expr) 
*** 7245,7250 **** 
--- 7245,7261 ---- 
              return fold (build (code, type, arg0, 
                                  build_real (TREE_TYPE (arg1), dconst0))); 
 
+           /* abs(x) < 0.0 -> false 
+              abs(x) >= 0.0 -> true.  */ 
+           if (REAL_VALUES_EQUAL (cst, dconst0) 
+               && TREE_CODE (arg0) == ABS_EXPR) 
+             { 
+               if (code == LT_EXPR) 
+                 return boolean_false_node; 
+               if (code == GE_EXPR) 
+                 return boolean_true_node; 
+             } 
+ 
            /* x != NaN is always true, other ops are always false.  */ 
            if (REAL_VALUE_ISNAN (cst) 
                && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1)))) 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14303