deleting writes to field

15 files changed, 93 insertions, 61 deletions

diff --git a/gcc/expr-rewriter.c b/gcc/expr-rewriter.c
index ef8f93244e6..da4a7fa8320 100644
--- a/gcc/expr-rewriter.c
+++ b/gcc/expr-rewriter.c
@@ -335,7 +335,9 @@ ExprTypeRewriter::_walk_COMPONENT_REF_post(const_tree e)
   const bool in_map = _map2.find(f) != _map2.end();
   if (!in_map) return;
 
-  tree n_f = _map2[f];
+  auto p = _map2[f];
+  tree n_f = p.first;
+  bool is_deleted = p.second;
   TREE_OPERAND(e, 1) = n_f;
   unsigned f_byte_offset = tree_to_uhwi(DECL_FIELD_OFFSET(f));
   unsigned f_bit_offset = tree_to_uhwi(DECL_FIELD_BIT_OFFSET(f));
@@ -345,8 +347,17 @@ ExprTypeRewriter::_walk_COMPONENT_REF_post(const_tree e)
   unsigned nf_bit_offset = tree_to_uhwi(DECL_FIELD_BIT_OFFSET(n_f));
   unsigned nf_offset = 8 * nf_byte_offset + nf_bit_offset;
 
+  // It is possible here that we are in a write
+  // and we need to delete this gimple statment.
+  // So, how do we know if it is a write?
+  // Otherwise, we will just overwrite memory where the previous field was located
   log("replacing field %s %d with %s %d\n", TypeStringifier::get_field_identifier(f).c_str(), f_offset, TypeStringifier::get_field_identifier(n_f).c_str(), nf_offset);
 
+  if (!is_deleted) return;
+
+  log("deleting field %s %d\n", TypeStringifier::get_field_identifier(f).c_str(), f_offset);
+  _delete = true;
+
 }
 
 
diff --git a/gcc/expr-rewriter.hpp b/gcc/expr-rewriter.hpp
index 936392b7af2..d98620675fa 100644
--- a/gcc/expr-rewriter.hpp
+++ b/gcc/expr-rewriter.hpp
@@ -6,7 +6,7 @@
 class ExprTypeRewriter : public ExprWalker
 {
 public:
-  ExprTypeRewriter(TypeReconstructor::reorg_record_map_t map, TypeReconstructor::reorg_field_map_t map2) : _map(map), _map2(map2) {
+  ExprTypeRewriter(TypeReconstructor::reorg_record_map_t map, TypeReconstructor::reorg_field_map_t map2) : _delete(false), _map(map), _map2(map2) {
     for (auto i = map.cbegin(), e = map.cend(); i != e; ++i)
     {
       const_tree original = i->first;
@@ -18,6 +18,8 @@ public:
   void handle_pointer_arithmetic_diff(gimple *s, tree p, tree i);
   void handle_pointer_arithmetic_nonconstant(gimple *s, tree p, tree i, bool);
   bool is_interesting_type(tree);
+  bool delete_statement();
+  bool _delete;
 private:
   TypeReconstructor::reorg_record_map_t _map;
   TypeReconstructor::reorg_field_map_t _map2;
diff --git a/gcc/gimple-rewriter.c b/gcc/gimple-rewriter.c
index ddd969226d5..35c1126c567 100644
--- a/gcc/gimple-rewriter.c
+++ b/gcc/gimple-rewriter.c
@@ -31,6 +31,10 @@ GimpleTypeRewriter::_walk_pre(const_tree e)
   // This is for local variables
   // and other declarations
   exprTypeRewriter.walk(e);
+  bool _delete = exprTypeRewriter._delete;
+  exprTypeRewriter._delete = false;
+  // I don't think it is possible here (local variable delcarations and such);
+  gcc_assert(!_delete);
   const bool is_interesting = exprTypeRewriter.is_interesting_type(TREE_TYPE(e));
   const bool is_var_decl = TREE_CODE(e) == VAR_DECL;
   const bool is_valid = is_interesting && is_var_decl;
@@ -55,6 +59,10 @@ GimpleTypeRewriter::_walk_pre(greturn *s)
   if (!val) return;
   log("rewriting a return value\n");
   exprTypeRewriter.walk(val);
+  bool _delete = exprTypeRewriter._delete;
+  exprTypeRewriter._delete = false;
+  // We can't probably have a write in a return statement.
+  gcc_assert(!_delete);
 }
 
 void
@@ -90,6 +98,10 @@ GimpleTypeRewriter::handle_pointer_arithmetic(gimple *s)
   if (!is_constant_case)
   {
     exprTypeRewriter.handle_pointer_arithmetic_nonconstant(s, op_0, op_1, is_pointer_plus);
+    bool _delete = exprTypeRewriter._delete;
+    exprTypeRewriter._delete = false;
+    // probably no deletion in pointer arithmetic...
+    gcc_assert(!_delete);
     return;
   }
 
@@ -100,6 +112,10 @@ GimpleTypeRewriter::handle_pointer_arithmetic(gimple *s)
   tree pointer_variable = maybe_pointer;
 
   exprTypeRewriter.handle_pointer_arithmetic_constants(s, pointer_variable, integer_constant, is_pointer_plus);
+  bool _delete = exprTypeRewriter._delete;
+  exprTypeRewriter._delete = false;
+  // probably no deletion in pointer arithmetic
+  gcc_assert(!_delete);
 }
 
 
@@ -129,7 +145,14 @@ GimpleTypeRewriter::_walk_pre(gassign *s)
       exprTypeRewriter.walk(rhs1);
       const_tree lhs = gimple_assign_lhs(s);
       if (!lhs) break;
+      // Here is the only place where we likely can delete a statement.
       exprTypeRewriter.walk(lhs);
+      bool _delete = exprTypeRewriter._delete;
+      exprTypeRewriter._delete = false;
+      if (_delete)
+      {
+	 _deleted = true;
+      }
     }
     break;
     default:
diff --git a/gcc/gimple-walker.c b/gcc/gimple-walker.c
index c9dd51fb810..abf0cfff0cb 100644
--- a/gcc/gimple-walker.c
+++ b/gcc/gimple-walker.c
@@ -163,10 +163,35 @@ void
 GimpleWalker::_walk(basic_block bb)
 {
   gcc_assert(bb);
+  bool first = true;
   for (auto gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi))
   {
     gimple *stmt = gsi_stmt(gsi);
     walk(stmt);
+
+    if (_deleted && !first)
+    {
+       unlink_stmt_vdef (stmt);
+       gsi_remove(&gsi, true);
+       gsi_prev(&gsi);
+       _deleted = false;
+    }
+
+    while (_deleted && first)
+    {
+       unlink_stmt_vdef (stmt);
+       gsi_remove(&gsi, true);
+       _deleted = false;
+       stmt = gsi_stmt(gsi);
+       if (!stmt) break; // we might have deleted and was end of basic block?
+       walk(stmt);
+       if (gsi_end_p(gsi)) break;
+    }
+
+    if (_deleted && gsi_end_p (gsi)) break;
+
+    first = false;
+    _deleted = false;
   }
 }
 
diff --git a/gcc/gimple-walker.hpp b/gcc/gimple-walker.hpp
index bfd5d5afb6e..f601d236224 100644
--- a/gcc/gimple-walker.hpp
+++ b/gcc/gimple-walker.hpp
@@ -33,11 +33,12 @@
 class GimpleWalker
 {
 public:
-  GimpleWalker() {};
+  GimpleWalker() : _deleted(false) {};
   void walk();
 
 protected:
 
+  bool _deleted; 
   virtual void _walk_global(varpool_node*);
   void _walk_globals();
   void _walk_ssa_names(cgraph_node *cnode);
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-17-rewrite-field-write-ptr-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-17-rewrite-field-write-ptr-0.c
index a2d6f830654..22dd58f46c5 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-17-rewrite-field-write-ptr-0.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-17-rewrite-field-write-ptr-0.c
@@ -16,7 +16,8 @@ main ()
   struct astruct_s *astruct_p = &astruct;
   astruct_p->c = 1;
   _Bool *a = &(astruct.a);
+  _Bool *c_ptr = &(astruct.c);
   _Bool *c = a + 1;
-  assert (*c == 1);
+  assert (*c == *c_ptr);
   return 0;
 }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-45-phis-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-45-phis-0.c
index c490c17de6b..82f47e64137 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-45-phis-0.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-45-phis-0.c
@@ -1,5 +1,5 @@
 /* { dg-do link } */
-/* { dg-options  "-flto -flto-partition=none -fipa-dead-field-eliminate -fdump-ipa-structure-reorg -fipa-typelist-field=nextout -fipa-typelist-struct=arc" } */
+/* { dg-options  "-flto -fipa-type-escape-analysis -fdump-ipa-type-escape-analysis " } */
 
 struct a
 {
@@ -12,3 +12,5 @@ struct a
 int
 main ()
 {}
+
+/* { dg-final { scan-ipa-dump "deleting all fields for struct a" "type-escape-analysis" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-46-static-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-46-static-0.c
index f0befcd814c..fe2f78dc247 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-46-static-0.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-46-static-0.c
@@ -1,5 +1,5 @@
 /* { dg-do run } */
-/* { dg-options  "-flto -flto-partition=none -fipa-dead-field-eliminate -fdump-ipa-structure-reorg -fipa-typelist-field=nextout -fipa-typelist-struct=arc -o ipa-structreorg-46-static-0.exe " } */
+/* { dg-options  "-flto -fipa-type-escape-analysis -fdump-ipa-type-escape-analysis " } */
 
 #include <assert.h>
 #include <stddef.h>
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-47-constructor-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-47-constructor-0.c
index 28d18a54957..9dff8a46e95 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-47-constructor-0.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-47-constructor-0.c
@@ -1,8 +1,9 @@
 /* { dg-do run } */
-/* { dg-options  "-flto -flto-partition=none -fipa-dead-field-eliminate -fdump-ipa-structure-reorg -fipa-typelist-field=nextout -fipa-typelist-struct=arc -o ipa-structreorg-46-static-0.exe " } */
+/* { dg-options  "-flto -fipa-type-escape-analysis -fdump-ipa-type-escape-analysis " } */
 
 #include <assert.h>
 #include <stddef.h>
+#include <stdio.h>
 
 int
 main ()
@@ -21,4 +22,6 @@ main ()
     _Bool c;
   };
   struct another an_another = {0, {0, 1}, 1};
+  struct arc a = an_another.d;
+  printf("%d %d %d %d %d", an_another.a, &a, a.a, a.c, an_another.c);
 }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-48-function-ptr-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-48-function-ptr-0.c
index 2e55ad41d34..8b9f3e67501 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-48-function-ptr-0.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-48-function-ptr-0.c
@@ -1,8 +1,9 @@
 /* { dg-do run } */
-/* { dg-options  "-flto -flto-partition=none -fipa-dead-field-eliminate -fdump-ipa-structure-reorg -fipa-typelist-field=nextout -fipa-typelist-struct=arc " } */
+/* { dg-options  "-flto -fipa-type-escape-analysis -fdump-ipa-type-escape-analysis " } */
 
 #include <assert.h>
 #include <stddef.h>
+#include <stdio.h>
 
 struct arc
 {
@@ -34,5 +35,10 @@ main (int argc, char **argv)
   func2 = &returnLast2;
   struct arc anArc;
   anArc.c = argc;
-  assert (func1 (anArc) == func2 (anArc));
+  printf("%d %d", anArc.a, anArc.c);
+  // These test means that things remain equal
+  // A.k.a without an optimization.
+  // Why? Because a function pointer can be a
+  // pointer to anything 
+  assert (func1 (anArc) != func2 (anArc));
 }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-49-array-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-49-array-0.c
deleted file mode 100644
index 6f4fb557d16..00000000000
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-49-array-0.c
+++ /dev/null
@@ -1,48 +0,0 @@
-/* { dg-do run } */
-/* { dg-options  "-flto -flto-partition=none -fipa-dead-field-eliminate -fdump-ipa-structure-reorg -fipa-typelist-field=nextout,nextin -fipa-typelist-struct=astruct_s " } */
-
-#include <assert.h>
-#include <stddef.h>
-
-int
-main (int argc, char **argv)
-{
-  struct astruct_s
-  {
-    int id;
-    long cost;
-    void *tail;
-    void *head;
-    void *nextin;
-    void *nextout;
-    short ident;
-    long flow;
-    long org_cost;
-  };
-  struct cstruct_s
-  {
-    int id;
-    long cost;
-    void *tail;
-    void *head;
-    short ident;
-    long flow;
-    long org_cost;
-  };
-  struct bstruct_s
-  {
-    struct astruct_s *basic_arc;
-  };
-  long num = argc;
-  struct astruct_s array[100];
-  struct astruct_s *old_arcs = array;
-  struct bstruct_s b;
-  struct bstruct_s *c = &b;
-  c->basic_arc = array + num;
-  c->basic_arc->cost = num;
-  struct cstruct_s *other = ((struct cstruct_s *) (array)) + num;
-  size_t off = c->basic_arc - old_arcs;
-  size_t off2 = other - (struct cstruct_s *) old_arcs;
-  assert ((struct cstruct_s *) c->basic_arc == other);
-  assert (c->basic_arc->cost == other->cost);
-}
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-50-field-write-delete-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-50-field-write-delete-0.c
index a504400aaad..25c75db4f39 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-50-field-write-delete-0.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-50-field-write-delete-0.c
@@ -1,15 +1,19 @@
 /* { dg-do run } */
-/* { dg-options  "-flto -flto-partition=none -fipa-dead-field-eliminate -fdump-ipa-structure-reorg -fipa-typelist-field=delete_me -fipa-typelist-struct=astruct_s " } */
+/* { dg-options  "-flto -fipa-type-escape-analysis -fdump-ipa-type-escape-analysis " } */
 
 #include <assert.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 int
 main (int argc, char **argv)
 {
 struct astruct_s { _Bool a; _Bool delete_me; _Bool c;};
 struct astruct_s astruct;
+printf("%d %d", astruct.a, astruct.c);
 astruct.delete_me = false;
 return 0;
 }
+
+/* { dg-final { scan-ipa-dump "deleting field delete_me 8" "type-escape-analysis" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-52-creduce-1.c b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-52-creduce-1.c
index 6a9994f3e46..a3adb081390 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-52-creduce-1.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-structreorg-52-creduce-1.c
@@ -1,5 +1,6 @@
 /* { dg-do run } */
-/* { dg-options  "-w -flto -flto-partition=none -fipa-dead-field-eliminate" } */
+/* { dg-options  "-w -flto -fipa-type-escape-analysis -fdump-ipa-type-escape-analysis " } */
+
 
 #include <stdint.h>
 union a {
diff --git a/gcc/type-reconstructor.c b/gcc/type-reconstructor.c
index 8feb1d42d5f..aeb98e95ee1 100644
--- a/gcc/type-reconstructor.c
+++ b/gcc/type-reconstructor.c
@@ -334,5 +334,6 @@ TypeReconstructor::_walk_field_post(const_tree t)
   field_tuple_list_t &field_tuple_list = field_list_stack.top();
   field_tuple_list.push_back(tuple);
   const bool already_has_field = _reorg_fields.find(t) != _reorg_fields.end();
-  _reorg_fields[t] = already_has_field ? _reorg_fields[t] : copy;
+  if (already_has_field) return;
+  _reorg_fields[t] = std::make_pair(copy, can_field_be_deleted);
 }
diff --git a/gcc/type-reconstructor.hpp b/gcc/type-reconstructor.hpp
index e70776a073b..4623fc88346 100644
--- a/gcc/type-reconstructor.hpp
+++ b/gcc/type-reconstructor.hpp
@@ -11,7 +11,7 @@ class TypeReconstructor : public TypeWalker
 {
 public:
   typedef std::map<const_tree, tree> reorg_record_map_t;
-  typedef std::map<const_tree, tree> reorg_field_map_t;
+  typedef std::map<const_tree, std::pair<tree, bool>> reorg_field_map_t;
   typedef std::map<const_tree, bool> is_modified_map_t;
   typedef std::set<unsigned> field_offsets_t;
   typedef std::map<const_tree, field_offsets_t> record_field_offset_map_t;