2009-09-22 Richard Guenther <rguenther@suse.de>
+ PR tree-optimization/41428
+ * tree-ssa-ccp.c (ccp_fold_stmt): New function.
+ (ccp_finalize): Pass it to substitute_and_fold.
+
+2009-09-22 Richard Guenther <rguenther@suse.de>
+
* tree-ssa-propagate.h (ssa_prop_fold_stmt_fn): Declare.
(substitute_and_fold): Adjust prototype.
* tree-vrp.c (vrp_evaluate_conditional): Make static.
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-ccp1-details" } */
+
+extern "C" void abort (void);
+inline void *operator new (__SIZE_TYPE__, void *__p) throw () { return __p; }
+
+int foo(void)
+{
+ float f = 0;
+ int *i = new (&f) int (1);
+ return *(int *)&f;
+}
+
+/* { dg-final { scan-tree-dump "Folded into: if \\\(1 != 0\\\)" "ccp1" } } */
+/* { dg-final { cleanup-tree-dump "ccp1" } } */
static prop_value_t *const_val;
static void canonicalize_float_value (prop_value_t *);
+static bool ccp_fold_stmt (gimple_stmt_iterator *);
/* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */
do_dbg_cnt ();
/* Perform substitutions based on the known constant values. */
- something_changed = substitute_and_fold (const_val, NULL);
+ something_changed = substitute_and_fold (const_val, ccp_fold_stmt);
free (const_val);
const_val = NULL;
return val;
}
+/* Fold the stmt at *GSI with CCP specific information that propagating
+ and regular folding does not catch. */
+
+static bool
+ccp_fold_stmt (gimple_stmt_iterator *gsi)
+{
+ gimple stmt = gsi_stmt (*gsi);
+ prop_value_t val;
+
+ if (gimple_code (stmt) != GIMPLE_COND)
+ return false;
+
+ /* Statement evaluation will handle type mismatches in constants
+ more gracefully than the final propagation. This allows us to
+ fold more conditionals here. */
+ val = evaluate_stmt (stmt);
+ if (val.lattice_val != CONSTANT
+ || TREE_CODE (val.value) != INTEGER_CST)
+ return false;
+
+ if (integer_zerop (val.value))
+ gimple_cond_make_false (stmt);
+ else
+ gimple_cond_make_true (stmt);
+
+ return true;
+}
+
/* Visit the assignment statement STMT. Set the value of its LHS to the
value computed by the RHS and store LHS in *OUTPUT_P. If STMT
creates virtual definitions, set the value of each new name to that