tree-ssa-ccp.c (latticevalue): Add UNKNOWN_VAL.

	* tree-ssa-ccp.c (latticevalue): Add UNKNOWN_VAL.
	(substitute_and_fold): Propigate into VUSE operands when possible.
	(visit_phi_node): Handle UNKNOWN_VAL latticevalue.
	(cp_lattice_meet): Handle merging of latticevalues when
	UNKNOWN_VAL is present.
	(visit_stmt): Visit assignments with V_MUST_DEFs.
	(visit_assignment): Gather ccp information for V_MUST_DEF operands.
	(ccp_fold): Deal with RHS' that are constant and virtual.
	(evaluate_stmt): Handle UNKNOWN_VAL likely values.
	(dump_lattice_value): Dump UNKNOWN_VAL latticevalues.
	(initialize): Mark statements with V_MUST_DEFs as VARYING only if the
	V_MUST_DEF operand is VARYING. Fix comment and include VOPS when
	computing immediate uses.
	(set_lattice_value): Disallow a UNKNOWN_VAL->UNDEFINED state
	transition.
	(replace_vuse_in): New function.
	(likely_value): Add check of vuse operands.
	(get_default_value): Set the default value of virtually defined
	variables to UKNOWN_VAL instead of VARYING.

testsuite:

	* gcc.dg/tree-ssa/20040721-1.c: New test.

From-SVN: r85055

gcc/ChangeLog

+2004-07-22  Brian Booth  <bbooth@redhat.com>
+
+	* tree-ssa-ccp.c (latticevalue): Add UNKNOWN_VAL.
+	(substitute_and_fold): Propigate into VUSE operands when possible.
+	(visit_phi_node): Handle UNKNOWN_VAL latticevalue.
+	(cp_lattice_meet): Handle merging of latticevalues when 
+	UNKNOWN_VAL is present.
+	(visit_stmt): Visit assignments with V_MUST_DEFs.
+	(visit_assignment): Gather ccp information for V_MUST_DEF operands.
+	(ccp_fold): Deal with RHS' that are constant and virtual.
+	(evaluate_stmt): Handle UNKNOWN_VAL likely values.
+	(dump_lattice_value): Dump UNKNOWN_VAL latticevalues.
+	(initialize): Mark statements with V_MUST_DEFs as VARYING only if the
+	V_MUST_DEF operand is VARYING. Fix comment and include VOPS when 
+	computing immediate uses.
+	(set_lattice_value): Disallow a UNKNOWN_VAL->UNDEFINED state 
+	transition.
+	(replace_vuse_in): New function.
+	(likely_value): Add check of vuse operands.
+	(get_default_value): Set the default value of virtually defined 
+	variables to UKNOWN_VAL instead of VARYING.
+
 2004-07-22  Richard Henderson  <rth@redhat.com>
 
 	* expr.c (emit_push_insn): Don't use set_mem_attributes.
@@ -1492,6 +1514,7 @@
 
 	* collect2.c (main):  Handle --no-demangle and --demangle flags.
 
+>>>>>>> 2.4547
 2004-07-13  Sebastian Pop  <pop@cri.ensmp.fr>
 
 	* Makefile.in (OBJS-common): Add tree-data-ref.o.

gcc/testsuite/ChangeLog

+2004-07-22  Brian Booth  <bbooth@redhat.com>
+
+	* gcc.dg/tree-ssa/20040721-1.c: New test.
+
 2004-07-22  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* g++.dg/template/crash20.c: New.

gcc/testsuite/gcc.dg/tree-ssa/20040721-1.c

+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-ccp-vops" } */
+
+/* Test to check whether global variables are being
+   constant propagated. */
+
+int G;
+
+foo (int i)
+{
+   if (i > 0)
+     G = 3;
+   else
+     G = 3;
+
+   if (G != 3)
+     link_error ();
+}
+
+main ()
+{
+   foo (0);
+   return 0;
+}
+
+/* There should be no G on the RHS of an assignment. */
+/* { dg-final { scan-tree-dump-times "= G;" 0 "ccp"} } */