re PR tree-optimization/15353 ([tree-ssa] Merge two "if"s if one subsumes the other.)

2007-06-12  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/15353
	PR tree-optimization/31657
	* passes.c (init_optimization_passes): Add pass_tree_ifcombine.
	* timevar.def: Add TV_TREE_IFCOMBINE.
	* tree-pass.h (pass_tree_ifcombine): Declare.
	* tree-ssa-ifcombine.c: New file.
	* tree-ssa-phiopt.c (blocks_in_phiopt_order): Export.
	* tree-flow.h (blocks_in_phiopt_order): Declare.
	* Makefile.in (OBJS-common): Add tree-ssa-ifcombine.o.
	(tree-ssa-ifcombine.o): New dependencies.

	* gcc.c-torture/execute/20070424-1.c: New testcase.
	* gcc.dg/tree-ssa/ssa-ifcombine-1.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-2.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-3.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-4.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-5.c: Likewise.

From-SVN: r125644

gcc/ChangeLog

+2007-06-12  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/15353
+	PR tree-optimization/31657
+	* passes.c (init_optimization_passes): Add pass_tree_ifcombine.
+	* timevar.def: Add TV_TREE_IFCOMBINE.
+	* tree-pass.h (pass_tree_ifcombine): Declare.
+	* tree-ssa-ifcombine.c: New file.
+	* tree-ssa-phiopt.c (blocks_in_phiopt_order): Export.
+	* tree-flow.h (blocks_in_phiopt_order): Declare.
+	* Makefile.in (OBJS-common): Add tree-ssa-ifcombine.o.
+	(tree-ssa-ifcombine.o): New dependencies.
+
 2007-06-12  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR rtl-optimization/32293

gcc/Makefile.in

@@ -1119,6 +1119,7 @@ OBJS-common = \
 	tree-ssa-dom.o \
 	tree-ssa-dse.o \
 	tree-ssa-forwprop.o \
+	tree-ssa-ifcombine.o \
 	tree-ssa-live.o \
 	tree-ssa-loop-ch.o \
 	tree-ssa-loop-im.o \
@@ -1942,6 +1943,9 @@ tree-ssa-forwprop.o : tree-ssa-forwprop.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
    $(TM_H) $(GGC_H) $(TREE_H) $(RTL_H) $(TM_P_H) $(BASIC_BLOCK_H) \
    $(TREE_FLOW_H) tree-pass.h $(TREE_DUMP_H) $(DIAGNOSTIC_H) $(TIMEVAR_H) \
    langhooks.h $(FLAGS_H)
+tree-ssa-ifcombine.o : tree-ssa-ifcombine.c $(CONFIG_H) $(SYSTEM_H) \
+   coretypes.h $(TM_H) $(TREE_H) $(BASIC_BLOCK_H) \
+   $(TREE_FLOW_H) tree-pass.h $(TREE_DUMP_H) $(DIAGNOSTIC_H) $(TIMEVAR_H)
 tree-ssa-phiopt.o : tree-ssa-phiopt.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
    $(TM_H) $(GGC_H) $(TREE_H) $(RTL_H) $(TM_P_H) $(BASIC_BLOCK_H) \
    $(TREE_FLOW_H) tree-pass.h $(TREE_DUMP_H) langhooks.h $(FLAGS_H) \

gcc/passes.c

@@ -575,6 +575,7 @@ init_optimization_passes (void)
 	 opportunities.  */
       NEXT_PASS (pass_phi_only_cprop);
 
+      NEXT_PASS (pass_tree_ifcombine);
       NEXT_PASS (pass_phiopt);
       NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_tail_recursion);

gcc/testsuite/ChangeLog

+2007-06-12  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/15353
+	PR tree-optimization/31657
+	* gcc.c-torture/execute/20070424-1.c: New testcase.
+	* gcc.dg/tree-ssa/ssa-ifcombine-1.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-ifcombine-2.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-ifcombine-3.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-ifcombine-4.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-ifcombine-5.c: Likewise.
+
 2007-06-12  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR rtl-optimization/32293

gcc/testsuite/gcc.c-torture/execute/20070424-1.c

+extern void abort (void);
+extern void exit (int);
+
+void do_exit (void) { exit (0); }
+void do_abort (void) { abort (); }
+
+void foo (int x, int a)
+{
+  if (x < a)
+    goto doit;
+  do_exit ();
+  if (x != a)
+    goto doit;
+
+  /* else */
+  do_abort ();
+  return;
+
+doit:
+  do_abort ();
+}
+
+int main()
+{
+  foo (1, 0);
+  return 0;
+}

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

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+/* Testcase for PR31657.  */
+
+int foo (int x, int a, int b)
+{
+  int c = 1 << a;
+  if (x & c)
+    if (x & (1 << b))
+      /* returning 1 causes phiopt to trigger in */
+      return 2;
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "\\|" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-2.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+/* Testcase for PR31657.  */
+
+int foo (int x, int a, int b)
+{
+  /* if ((x & a) || (x & b)) */
+  if (x & a)
+    goto doit;
+  if (x & b)
+    goto doit;
+
+  /* else */
+  return 0;
+
+  /* then - returing 1 causes phiopt to trigger */
+doit:
+  return 2;
+}
+
+/* { dg-final { scan-tree-dump "\\|" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-3.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+/* Testcase extracted from PR15353.  */
+
+int foo (int x, int a)
+{
+  /* if ((x > a) || (x == a)) */
+  if (x > a)
+    goto doit;
+  if (x == a)
+    goto doit;
+
+  /* else */
+  return 0;
+
+  /* then - returing 1 causes phiopt to trigger */
+doit:
+  return 2;
+}
+
+/* { dg-final { scan-tree-dump ">=" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-4.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+/* Testcase extracted from PR15353.  */
+
+extern void bar(void);
+
+void foo (int x, int a)
+{
+  /* if ((x < a) || (x != a)) return; else bar (); */
+  if (x < a)
+    return;
+  if (x != a)
+    return;
+
+  /* else */
+  bar ();
+}
+
+/* { dg-final { scan-tree-dump "!=" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-5.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+/* Testcase from PR15353.  */
+
+int g(void);
+int h(void);
+int f(int *i, int *j)
+{
+  while (1)
+    {
+      if (*i > *j || *i == *j)
+        break;
+      return g();
+    }
+  return h();
+}
+
+/* { dg-final { scan-tree-dump ">=" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/timevar.def

@@ -187,6 +187,7 @@ DEFTIMEVAR (TV_REG_STACK             , "reg stack")
 DEFTIMEVAR (TV_FINAL                 , "final")
 DEFTIMEVAR (TV_SYMOUT                , "symout")
 DEFTIMEVAR (TV_VAR_TRACKING          , "variable tracking")
+DEFTIMEVAR (TV_TREE_IFCOMBINE        , "tree if-combine")
 
 /* Everything else in rest_of_compilation not included above.  */
 DEFTIMEVAR (TV_REST_OF_COMPILATION   , "rest of compilation")

gcc/tree-flow.h

@@ -962,6 +962,7 @@ extern tree get_vectype_for_scalar_type (tree);
 
 /* In tree-ssa-phiopt.c */
 bool empty_block_p (basic_block);
+basic_block *blocks_in_phiopt_order (void);
 
 /* In tree-ssa-loop*.c  */
 

gcc/tree-pass.h

@@ -298,6 +298,7 @@ extern struct tree_opt_pass pass_warn_function_noreturn;
 extern struct tree_opt_pass pass_phiopt;
 extern struct tree_opt_pass pass_forwprop;
 extern struct tree_opt_pass pass_phiprop;
+extern struct tree_opt_pass pass_tree_ifcombine;
 extern struct tree_opt_pass pass_dse;
 extern struct tree_opt_pass pass_nrv;
 extern struct tree_opt_pass pass_mark_used_blocks;

gcc/tree-ssa-phiopt.c

@@ -45,7 +45,6 @@ static bool minmax_replacement (basic_block, basic_block,
 static bool abs_replacement (basic_block, basic_block,
 			     edge, edge, tree, tree, tree);
 static void replace_phi_edge_with_variable (basic_block, edge, tree, tree);
-static basic_block *blocks_in_phiopt_order (void);
 
 /* This pass tries to replaces an if-then-else block with an
    assignment.  We have four kinds of transformations.  Some of these
@@ -247,7 +246,7 @@ tree_ssa_phiopt (void)
    that if a block X has just a single predecessor Y, then Y is after X in the
    ordering.  */
 
-static basic_block *
+basic_block *
 blocks_in_phiopt_order (void)
 {
   basic_block x, y;