+2007-01-10 Robert Kennedy <jimbob@google.com>
+
+ * fold-const.c (fold_comparison): Fold comparisons like (x *
+ 1000 < 0) to (x < 0).
+
2007-01-10 Ian Lance Taylor <iant@google.com>
* tree-pretty-print.c (dump_generic_node): Print parentheses when
variable2);
}
+ /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
+ signed arithmetic case. That form is created by the compiler
+ often enough for folding it to be of value. One example is in
+ computing loop trip counts after Operator Strength Reduction. */
+ if (!(flag_wrapv || flag_trapv)
+ && !TYPE_UNSIGNED (TREE_TYPE (arg0))
+ && TREE_CODE (arg0) == MULT_EXPR
+ && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
+ && integer_zerop (arg1))
+ {
+ tree const1 = TREE_OPERAND (arg0, 1);
+ tree const2 = arg1; /* zero */
+ tree variable1 = TREE_OPERAND (arg0, 0);
+ enum tree_code cmp_code = code;
+
+ gcc_assert (!integer_zerop (const1));
+
+ /* If const1 is negative we swap the sense of the comparison. */
+ if (tree_int_cst_sgn (const1) < 0)
+ cmp_code = swap_tree_comparison (cmp_code);
+
+ return fold_build2 (cmp_code, type, variable1, const2);
+ }
+
tem = maybe_canonicalize_comparison (code, type, arg0, arg1);
if (tem)
return tem;
+2007-01-10 Robert Kennedy <jimbob@google.com>
+
+ * gcc.dg/fold-compare-2.c: New test case for fold_comparison.
+
2007-01-09 Brooks Moses <brooks.moses@codesourcery.com>
* gfortran.dg/chkbits.f90: Added IBCLR tests; test calls