Re: [RFC][IPA-VRP] Re-factor tree-vrp to factor out common code

[kugan <kugan.vivekanandarajah@linaro.org>]

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Hi,

Now that early vrp is moved as part of tree-vrp, there is only minimal 
interface tree-vrp should expose for ipa-vrp. However, I have not found 
the right place to place struct value_range (with GTY marker) and enum 
value_range_type.

enum value_range_type is needed in tree-ssanames.[h|c] and in all the 
places where get|set_range_info is used.

struct value_range is needed in ipa-prop.h, therefore all the places 
ipa-prop.h is included.

One option is to place it in tree-vrp.h and expose this to GTY 
infrastructure. Then include it in all the places we need any of these 
types. It is in lots of c files.

I have now placed both in tree.h. Even though that compiles, I am not 
convinced that is the right place.

I would appreciate comment/preferences in this regard. I am also 
attaching the current version of this patch for review. I will update it 
based on the comments.

Thanks,
Kugan




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From 2e7d10923fefddafdeffc571e870508ac0ee193c Mon Sep 17 00:00:00 2001
From: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
Date: Tue, 21 Jun 2016 12:42:44 +1000
Subject: [PATCH 4/7] Refactor vrp

---
 gcc/tree-ssanames.h |  5 -----
 gcc/tree-vrp.c      | 50 ++++++++++++--------------------------------------
 gcc/tree-vrp.h      | 23 +++++++++++++++++++++++
 gcc/tree.h          | 31 +++++++++++++++++++++++++++++++
 4 files changed, 66 insertions(+), 43 deletions(-)
 create mode 100644 gcc/tree-vrp.h

diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h
index c81b1a1..8e66ce6 100644
--- a/gcc/tree-ssanames.h
+++ b/gcc/tree-ssanames.h
@@ -62,11 +62,6 @@ struct GTY ((variable_size)) range_info_def {
 #define num_ssa_names (vec_safe_length (cfun->gimple_df->ssa_names))
 #define ssa_name(i) ((*cfun->gimple_df->ssa_names)[(i)])
 
-
-/* Type of value ranges.  See value_range_d In tree-vrp.c for a
-   description of these types.  */
-enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING };
-
 /* Sets the value range to SSA.  */
 extern void set_range_info (tree, enum value_range_type, const wide_int_ref &,
 			    const wide_int_ref &);
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index edaacf2..a318d39 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -59,32 +59,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "target.h"
 #include "case-cfn-macros.h"
 #include "alloc-pool.h"
-
-/* Range of values that can be associated with an SSA_NAME after VRP
-   has executed.  */
-struct value_range
-{
-  /* Lattice value represented by this range.  */
-  enum value_range_type type;
-
-  /* Minimum and maximum values represented by this range.  These
-     values should be interpreted as follows:
-
-	- If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
-	  be NULL.
-
-	- If TYPE == VR_RANGE then MIN holds the minimum value and
-	  MAX holds the maximum value of the range [MIN, MAX].
-
-	- If TYPE == ANTI_RANGE the variable is known to NOT
-	  take any values in the range [MIN, MAX].  */
-  tree min;
-  tree max;
-
-  /* Set of SSA names whose value ranges are equivalent to this one.
-     This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
-  bitmap equiv;
-};
+#include "tree-vrp.h"
 
 #define VR_INITIALIZER { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL }
 
@@ -108,8 +83,6 @@ live_on_edge (edge e, tree name)
 /* Local functions.  */
 static int compare_values (tree val1, tree val2);
 static int compare_values_warnv (tree val1, tree val2, bool *);
-static void vrp_meet (value_range *, value_range *);
-static void vrp_intersect_ranges (value_range *, value_range *);
 static tree vrp_evaluate_conditional_warnv_with_ops (enum tree_code,
 						     tree, tree, bool, bool *,
 						     bool *);
@@ -4605,7 +4578,7 @@ compare_range_with_value (enum tree_code comp, value_range *vr, tree val,
 
 /* Debugging dumps.  */
 
-void dump_value_range (FILE *, value_range *);
+void dump_value_range (FILE *, const value_range *);
 void debug_value_range (value_range *);
 void dump_all_value_ranges (FILE *);
 void debug_all_value_ranges (void);
@@ -4616,7 +4589,7 @@ void debug_vr_equiv (bitmap);
 /* Dump value range VR to FILE.  */
 
 void
-dump_value_range (FILE *file, value_range *vr)
+dump_value_range (FILE *file, const value_range *vr)
 {
   if (vr == NULL)
     fprintf (file, "[]");
@@ -8447,7 +8420,7 @@ intersect_ranges (enum value_range_type *vr0type,
 /* Intersect the two value-ranges *VR0 and *VR1 and store the result
    in *VR0.  This may not be the smallest possible such range.  */
 
-static void
+void
 vrp_intersect_ranges_1 (value_range *vr0, value_range *vr1)
 {
   value_range saved;
@@ -8499,7 +8472,7 @@ vrp_intersect_ranges_1 (value_range *vr0, value_range *vr1)
     bitmap_copy (vr0->equiv, vr1->equiv);
 }
 
-static void
+void
 vrp_intersect_ranges (value_range *vr0, value_range *vr1)
 {
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -8524,7 +8497,7 @@ vrp_intersect_ranges (value_range *vr0, value_range *vr1)
    may not be the smallest possible such range.  */
 
 static void
-vrp_meet_1 (value_range *vr0, value_range *vr1)
+vrp_meet_1 (value_range *vr0, const value_range *vr1)
 {
   value_range saved;
 
@@ -8596,8 +8569,8 @@ vrp_meet_1 (value_range *vr0, value_range *vr1)
     bitmap_clear (vr0->equiv);
 }
 
-static void
-vrp_meet (value_range *vr0, value_range *vr1)
+void
+vrp_meet (value_range *vr0, const value_range *vr1)
 {
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
@@ -10171,7 +10144,7 @@ finalize_jump_threads (void)
 /* Traverse all the blocks folding conditionals with known ranges.  */
 
 static void
-vrp_finalize (bool warn_array_bounds_p)
+vrp_finalize (bool jump_thread_p, bool warn_array_bounds_p)
 {
   size_t i;
 
@@ -10212,7 +10185,8 @@ vrp_finalize (bool warn_array_bounds_p)
 
   /* We must identify jump threading opportunities before we release
      the datastructures built by VRP.  */
-  identify_jump_threads ();
+  if (jump_thread_p)
+    identify_jump_threads ();
 
   /* Free allocated memory.  */
   free (vr_value);
@@ -10296,7 +10270,7 @@ execute_vrp (bool warn_array_bounds_p)
 
   vrp_initialize ();
   ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node);
-  vrp_finalize (warn_array_bounds_p);
+  vrp_finalize (true, warn_array_bounds_p);
 
   free_numbers_of_iterations_estimates (cfun);
 
diff --git a/gcc/tree-vrp.h b/gcc/tree-vrp.h
new file mode 100644
index 0000000..38aacf5
--- /dev/null
+++ b/gcc/tree-vrp.h
@@ -0,0 +1,23 @@
+/* Support routines for Value Range Propagation (VRP).
+   Copyright (C) Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+extern void vrp_intersect_ranges (value_range *vr0, value_range *vr1);
+extern void vrp_meet (value_range *vr0, const value_range *vr1);
+extern void dump_value_range (FILE *, const value_range *);
+
diff --git a/gcc/tree.h b/gcc/tree.h
index 90413fc..8fc4f4f 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -230,6 +230,37 @@ as_internal_fn (combined_fn code)
 
 #define TREE_CODE_LENGTH(CODE)	tree_code_length[(int) (CODE)]
 
+/* Type of value ranges.  See value_range_d In tree-vrp.c for a
+   description of these types.  */
+enum value_range_type { VR_UNDEFINED, VR_RANGE,
+			VR_ANTI_RANGE, VR_VARYING, VR_LAST };
+
+/* Range of values that can be associated with an SSA_NAME after VRP
+   has executed.  */
+struct GTY(()) value_range
+{
+  /* Lattice value represented by this range.  */
+  enum value_range_type type;
+
+  /* Minimum and maximum values represented by this range.  These
+     values should be interpreted as follows:
+
+	- If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
+	  be NULL.
+
+	- If TYPE == VR_RANGE then MIN holds the minimum value and
+	  MAX holds the maximum value of the range [MIN, MAX].
+
+	- If TYPE == ANTI_RANGE the variable is known to NOT
+	  take any values in the range [MIN, MAX].  */
+  tree min;
+  tree max;
+
+  /* Set of SSA names whose value ranges are equivalent to this one.
+     This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
+  bitmap equiv;
+};
+
 
 /* Helper macros for math builtins.  */
 
-- 
1.9.1