From edd4200e2b3e94d5c124900657b91c22dfe9c557 Mon Sep 17 00:00:00 2001
From: Mingchuan Wu <wumingchuan1992@foxmail.com>
Date: Wed, 15 Jun 2022 16:00:25 +0800
Subject: [PATCH 04/12] [DFE] Add Dead Field Elimination in Struct-Reorg.

We can transform gimple to eliminate fields that are never read
and remove their redundant stmts.
Also we adapted the partial escape_cast_another_ptr for struct relayout.
Add flag -fipa-struct-reorg=3 to enable dead field elimination.
---
 gcc/common.opt                                |   4 +-
 gcc/ipa-struct-reorg/ipa-struct-reorg.c       | 209 ++++++++++++++++--
 gcc/ipa-struct-reorg/ipa-struct-reorg.h       |   9 +-
 gcc/testsuite/gcc.dg/struct/dfe_DTE_verify.c  |  86 +++++++
 .../gcc.dg/struct/dfe_ele_minus_verify.c      |  60 +++++
 .../gcc.dg/struct/dfe_mem_ref_offset.c        |  58 +++++
 .../struct/dfe_mul_layer_ptr_record_bug.c     |  30 +++
 gcc/testsuite/gcc.dg/struct/dfe_ptr_diff.c    |  71 ++++++
 .../gcc.dg/struct/dfe_ptr_negate_expr.c       |  55 +++++
 gcc/testsuite/gcc.dg/struct/dfe_ptr_ptr.c     |  55 +++++
 gcc/testsuite/gcc.dg/struct/struct-reorg.exp  |  21 +-
 11 files changed, 639 insertions(+), 19 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_DTE_verify.c
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_ele_minus_verify.c
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_mem_ref_offset.c
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_mul_layer_ptr_record_bug.c
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_ptr_diff.c
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_ptr_negate_expr.c
 create mode 100644 gcc/testsuite/gcc.dg/struct/dfe_ptr_ptr.c

diff --git a/gcc/common.opt b/gcc/common.opt
index 7fc075d35..b5ea3c7a1 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1884,8 +1884,8 @@ Common Report Var(flag_ipa_struct_reorg) Init(0) Optimization
 Perform structure layout optimizations.
 
 fipa-struct-reorg=
-Common RejectNegative Joined UInteger Var(struct_layout_optimize_level) Init(0) IntegerRange(0, 2)
--fipa-struct-reorg=[0,1,2] adding none, struct-reorg, reorder-fields optimizations.
+Common RejectNegative Joined UInteger Var(struct_layout_optimize_level) Init(0) IntegerRange(0, 3)
+-fipa-struct-reorg=[0,1,2,3] adding none, struct-reorg, reorder-fields, dfe optimizations.
 
 fipa-extend-auto-profile
 Common Report Var(flag_ipa_extend_auto_profile)
diff --git a/gcc/ipa-struct-reorg/ipa-struct-reorg.c b/gcc/ipa-struct-reorg/ipa-struct-reorg.c
index 9214ee74a..2fa560239 100644
--- a/gcc/ipa-struct-reorg/ipa-struct-reorg.c
+++ b/gcc/ipa-struct-reorg/ipa-struct-reorg.c
@@ -81,6 +81,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-pretty-print.h"
 #include "gimple-pretty-print.h"
 #include "gimple-iterator.h"
+#include "gimple-walk.h"
 #include "cfg.h"
 #include "ssa.h"
 #include "tree-dfa.h"
@@ -238,11 +239,44 @@ enum srmode
   STRUCT_LAYOUT_OPTIMIZE
 };
 
+/* Enum the struct layout optimize level,
+   which should be the same as the option -fstruct-reorg=.  */
+
+enum struct_layout_opt_level
+{
+  NONE = 0,
+  STRUCT_REORG,
+  STRUCT_REORDER_FIELDS,
+  DEAD_FIELD_ELIMINATION
+};
+
 static bool is_result_of_mult (tree arg, tree *num, tree struct_size);
 bool isptrptr (tree type);
 
 srmode current_mode;
 
+hash_map<tree, tree> replace_type_map;
+
+/* Return true if one of these types is created by struct-reorg.  */
+
+static bool
+is_replace_type (tree type1, tree type2)
+{
+  if (replace_type_map.is_empty ())
+    return false;
+  if (type1 == NULL_TREE || type2 == NULL_TREE)
+    return false;
+  tree *type_value = replace_type_map.get (type1);
+  if (type_value)
+    if (types_compatible_p (*type_value, type2))
+      return true;
+  type_value = replace_type_map.get (type2);
+  if (type_value)
+    if (types_compatible_p (*type_value, type1))
+      return true;
+  return false;
+}
+
 } // anon namespace
 
 namespace struct_reorg {
@@ -318,12 +352,13 @@ srfunction::simple_dump (FILE *file)
 /* Constructor of FIELD. */
 
 srfield::srfield (tree field, srtype *base)
-  : offset(int_byte_position (field)),
+  : offset (int_byte_position (field)),
     fieldtype (TREE_TYPE (field)),
     fielddecl (field),
-    base(base),
-    type(NULL),
-    clusternum(0)
+    base (base),
+    type (NULL),
+    clusternum (0),
+    field_access (EMPTY_FIELD)
 {
   for(int i = 0;i < max_split; i++)
     newfield[i] = NULL_TREE;
@@ -362,6 +397,25 @@ srtype::srtype (tree type)
     }
 }
 
+/* Check it if all fields in the RECORD_TYPE are referenced.  */
+
+bool
+srtype::has_dead_field (void)
+{
+  bool may_dfe = false;
+  srfield *this_field;
+  unsigned i;
+  FOR_EACH_VEC_ELT (fields, i, this_field)
+    {
+      if (!(this_field->field_access & READ_FIELD))
+	{
+	  may_dfe = true;
+	  break;
+	}
+    }
+  return may_dfe;
+}
+
 /* Mark the type as escaping type E at statement STMT. */
 
 void
@@ -833,6 +887,10 @@ srtype::create_new_type (void)
   for (unsigned i = 0; i < fields.length (); i++)
     {
       srfield *f = fields[i];
+      if (current_mode == STRUCT_LAYOUT_OPTIMIZE
+	  && struct_layout_optimize_level >= DEAD_FIELD_ELIMINATION
+	  && !(f->field_access & READ_FIELD))
+	continue;
       f->create_new_fields (newtype, newfields, newlast);
     }
 
@@ -854,6 +912,16 @@ srtype::create_new_type (void)
 
   warn_padded = save_warn_padded;
 
+  if (current_mode == STRUCT_LAYOUT_OPTIMIZE
+      && replace_type_map.get (this->newtype[0]) == NULL)
+    replace_type_map.put (this->newtype[0], this->type);
+  if (dump_file)
+    {
+      if (current_mode == STRUCT_LAYOUT_OPTIMIZE
+	  && struct_layout_optimize_level >= DEAD_FIELD_ELIMINATION
+	  && has_dead_field ())
+	fprintf (dump_file, "Dead field elimination.\n");
+    }
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
       fprintf (dump_file, "Created %d types:\n", maxclusters);
@@ -1128,12 +1196,12 @@ csrtype::init_type_info (void)
 
   /* Close enough to pad to improve performance.
      33~63 should pad to 64 but 33~48 (first half) are too far away, and
-     65~127 should pad to 128 but 65~96 (first half) are too far away.  */
+     65~127 should pad to 128 but 65~80 (first half) are too far away.  */
   if (old_size > 48 && old_size < 64)
     {
       new_size = 64;
     }
-  if (old_size > 96 && old_size < 128)
+  if (old_size > 80 && old_size < 128)
     {
       new_size = 128;
     }
@@ -1272,6 +1340,7 @@ public:
   bool has_rewritten_type (srfunction*);
   void maybe_mark_or_record_other_side (tree side, tree other, gimple *stmt);
   unsigned execute_struct_relayout (void);
+  bool remove_dead_field_stmt (tree lhs);
 };
 
 struct ipa_struct_relayout
@@ -3206,6 +3275,90 @@ ipa_struct_reorg::find_vars (gimple *stmt)
     }
 }
 
+/* Update field_access in srfield.  */
+
+static void
+update_field_access (tree record, tree field, unsigned access, void *data)
+{
+  srtype *this_srtype = ((ipa_struct_reorg *)data)->find_type (record);
+  if (this_srtype == NULL)
+    return;
+  srfield *this_srfield = this_srtype->find_field (int_byte_position (field));
+  if (this_srfield == NULL)
+    return;
+
+  this_srfield->field_access |= access;
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    {
+      fprintf (dump_file, "record field access %d:", access);
+      print_generic_expr (dump_file, record);
+      fprintf (dump_file, "  field:");
+      print_generic_expr (dump_file, field);
+      fprintf (dump_file, "\n");
+    }
+  return;
+}
+
+/* A callback for walk_stmt_load_store_ops to visit store.  */
+
+static bool
+find_field_p_store (gimple *, tree node, tree op, void *data)
+{
+  if (TREE_CODE (op) != COMPONENT_REF)
+    return false;
+  tree node_type = TREE_TYPE (node);
+  if (!handled_type (node_type))
+    return false;
+
+  update_field_access (node_type, TREE_OPERAND (op, 1), WRITE_FIELD, data);
+
+  return false;
+}
+
+/* A callback for walk_stmt_load_store_ops to visit load.  */
+
+static bool
+find_field_p_load (gimple *, tree node, tree op, void *data)
+{
+  if (TREE_CODE (op) != COMPONENT_REF)
+    return false;
+  tree node_type = TREE_TYPE (node);
+  if (!handled_type (node_type))
+    return false;
+
+  update_field_access (node_type, TREE_OPERAND (op, 1), READ_FIELD, data);
+
+  return false;
+}
+
+/* Determine whether the stmt should be deleted.  */
+
+bool
+ipa_struct_reorg::remove_dead_field_stmt (tree lhs)
+{
+  tree base = NULL_TREE;
+  bool indirect = false;
+  srtype *t = NULL;
+  srfield *f = NULL;
+  bool realpart = false;
+  bool imagpart = false;
+  bool address = false;
+  bool escape_from_base = false;
+  if (!get_type_field (lhs, base, indirect, t, f, realpart, imagpart,
+		       address, escape_from_base))
+    return false;
+  if (t ==NULL)
+    return false;
+  if (t->newtype[0] == t->type)
+    return false;
+  if (f == NULL)
+    return false;
+  if (f->newfield[0] == NULL
+      && (f->field_access & WRITE_FIELD))
+    return true;
+  return false;
+}
+
 /* Maybe record access of statement for further analaysis. */
 
 void
@@ -3227,6 +3380,13 @@ ipa_struct_reorg::maybe_record_stmt (cgraph_node *node, gimple *stmt)
     default:
       break;
     }
+  if (current_mode == STRUCT_LAYOUT_OPTIMIZE
+      && struct_layout_optimize_level >= DEAD_FIELD_ELIMINATION)
+    {
+      /* Look for loads and stores.  */
+      walk_stmt_load_store_ops (stmt, this, find_field_p_load,
+				find_field_p_store);
+    }
 }
 
 /* Calculate the multiplier.  */
@@ -3543,8 +3703,11 @@ ipa_struct_reorg::maybe_mark_or_record_other_side (tree side, tree other, gimple
     }
   else if (type != d->type)
     {
-      type->mark_escape (escape_cast_another_ptr, stmt);
-      d->type->mark_escape (escape_cast_another_ptr, stmt);
+      if (!is_replace_type (d->type->type, type->type))
+	{
+	  type->mark_escape (escape_cast_another_ptr, stmt);
+	  d->type->mark_escape (escape_cast_another_ptr, stmt);
+	}
     }
   /* x_1 = y.x_nodes; void *x;
      Directly mark the structure pointer type assigned
@@ -4131,8 +4294,9 @@ ipa_struct_reorg::check_type_and_push (tree newdecl, srdecl *decl,
 	}
       /* If we have a non void* or a decl (which is hard to track),
          then mark the type as escaping.  */
-      if (!VOID_POINTER_P (TREE_TYPE (newdecl))
-	  || DECL_P (newdecl))
+      if (replace_type_map.get (type->type) == NULL
+	  && (!VOID_POINTER_P (TREE_TYPE (newdecl))
+	      || DECL_P (newdecl)))
 	{
 	  if (dump_file && (dump_flags & TDF_DETAILS))
 	    {
@@ -4142,7 +4306,7 @@ ipa_struct_reorg::check_type_and_push (tree newdecl, srdecl *decl,
 	      print_generic_expr (dump_file, TREE_TYPE (newdecl));
 	      fprintf (dump_file, "\n");
 	    }
-          type->mark_escape (escape_cast_another_ptr, stmt);
+	  type->mark_escape (escape_cast_another_ptr, stmt);
 	  return;
 	}
       /* At this point there should only be unkown void* ssa names. */
@@ -4465,11 +4629,13 @@ ipa_struct_reorg::check_other_side (srdecl *decl, tree other, gimple *stmt, vec<
 
       return;
     }
+  if (!is_replace_type (t1->type, type->type))
+    {
+      if (t1)
+	t1->mark_escape (escape_cast_another_ptr, stmt);
 
-  if (t1)
-    t1->mark_escape (escape_cast_another_ptr, stmt);
-
-  type->mark_escape (escape_cast_another_ptr, stmt);
+      type->mark_escape (escape_cast_another_ptr, stmt);
+    }
 }
 
 
@@ -5722,6 +5888,19 @@ bool
 ipa_struct_reorg::rewrite_assign (gassign *stmt, gimple_stmt_iterator *gsi)
 {
   bool remove = false;
+
+  if (current_mode == STRUCT_LAYOUT_OPTIMIZE
+      && struct_layout_optimize_level >= DEAD_FIELD_ELIMINATION
+      && remove_dead_field_stmt (gimple_assign_lhs (stmt)))
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file, "\n rewriting statement (remove): \n");
+	  print_gimple_stmt (dump_file, stmt, 0);
+	}
+      return true;
+    }
+
   if (gimple_clobber_p (stmt))
     {
       tree lhs = gimple_assign_lhs (stmt);
diff --git a/gcc/ipa-struct-reorg/ipa-struct-reorg.h b/gcc/ipa-struct-reorg/ipa-struct-reorg.h
index 54b0dc655..936c0fa6f 100644
--- a/gcc/ipa-struct-reorg/ipa-struct-reorg.h
+++ b/gcc/ipa-struct-reorg/ipa-struct-reorg.h
@@ -142,6 +142,7 @@ public:
 
   bool create_new_type (void);
   void analyze (void);
+  bool has_dead_field (void);
   void mark_escape (escape_type, gimple *stmt);
   bool has_escaped (void)
   {
@@ -163,6 +164,12 @@ public:
   }
 };
 
+/* Bitflags used for determining if a field
+     is never accessed, read or written.  */
+const unsigned EMPTY_FIELD = 0x0u;
+const unsigned READ_FIELD = 0x01u;
+const unsigned WRITE_FIELD = 0x02u;
+
 struct srfield
 {
   unsigned HOST_WIDE_INT offset;
@@ -174,7 +181,7 @@ struct srfield
   unsigned clusternum;
 
   tree newfield[max_split];
-
+  unsigned field_access; /* FIELD_DECL -> bitflag (use for dfe).  */
   // Constructors
   srfield (tree field, srtype *base);
 
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_DTE_verify.c b/gcc/testsuite/gcc.dg/struct/dfe_DTE_verify.c
new file mode 100644
index 000000000..4261d2352
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_DTE_verify.c
@@ -0,0 +1,86 @@
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node node_t;
+typedef struct node *node_p;
+
+typedef struct arc arc_t;
+typedef struct arc *arc_p;
+
+typedef struct network
+{    
+  arc_p arcs;
+  arc_p sorted_arcs;
+  int x;
+  node_p nodes;
+  node_p stop_nodes;
+} network_t;
+
+struct node
+{
+  int64_t potential;
+  int orientation;
+  node_p child;
+  node_p pred;
+  node_p sibling;
+  node_p sibling_prev;
+  arc_p basic_arc;
+  arc_p firstout;
+  arc_p firstin;
+  arc_p arc_tmp;
+  int64_t flow;
+  int64_t depth;
+  int number;
+  int time;
+};
+
+struct arc
+{
+  int id;
+  int64_t cost;
+  node_p tail;
+  node_p head;
+  short ident;
+  arc_p nextout;
+  arc_p nextin;
+  int64_t flow;
+  int64_t org_cost;
+  network_t* net_add;
+};
+
+
+const int MAX = 100;
+
+/* let it escape_array, "Type is used in an array [not handled yet]".  */
+network_t* net[2];
+arc_p stop_arcs = NULL;
+
+int
+main ()
+{
+  net[0] = (network_t*) calloc (1, sizeof(network_t));
+  net[0]->arcs = (arc_p) calloc (MAX, sizeof (arc_t));
+  stop_arcs = (arc_p) calloc (MAX, sizeof (arc_t));
+
+  net[0]->arcs->id = 100;
+
+  for (unsigned i = 0; i < 3; i++)
+    {        
+      net[0]->arcs->id = net[0]->arcs->id + 2;
+      stop_arcs->cost = net[0]->arcs->id / 2;
+      stop_arcs->net_add = net[0];
+      printf("stop_arcs->cost = %ld\n", stop_arcs->cost);
+      net[0]->arcs++;
+      stop_arcs++;
+    }
+
+  if( net[1] != 0 && stop_arcs != 0)
+    {
+      return -1;
+    }
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 2 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_ele_minus_verify.c b/gcc/testsuite/gcc.dg/struct/dfe_ele_minus_verify.c
new file mode 100644
index 000000000..42d38c63a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_ele_minus_verify.c
@@ -0,0 +1,60 @@
+// verify newarc[cmp-1].flow
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node node_t;
+typedef struct node *node_p;
+
+typedef struct arc arc_t;
+typedef struct arc *arc_p;
+
+struct node
+{
+  int64_t potential;
+  int orientation;
+  node_p child;
+  node_p pred;
+  node_p sibling;
+  node_p sibling_prev;
+  arc_p basic_arc;
+  arc_p firstout;
+  arc_p firstin;
+  arc_p arc_tmp;
+  int64_t flow;
+  int64_t depth;
+  int number;
+  int time;
+};
+
+struct arc
+{
+  int id;
+  int64_t cost;
+  node_p tail;
+  node_p head;
+  short ident;
+  arc_p nextout;
+  arc_p nextin;
+  int64_t flow;
+  int64_t org_cost;
+};
+
+const int MAX = 100;
+arc_p ap = NULL;
+
+int
+main ()
+{
+  ap = (arc_p) calloc(MAX, sizeof(arc_t));
+  printf("%d\n", ap[0].id);
+  for (int i = 1; i < MAX; i++)
+    {
+      ap[i-1].id = 500;
+    }
+  printf("%d\n", ap[0].id);
+  return 0; 
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 2 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_mem_ref_offset.c b/gcc/testsuite/gcc.dg/struct/dfe_mem_ref_offset.c
new file mode 100644
index 000000000..53583fe82
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_mem_ref_offset.c
@@ -0,0 +1,58 @@
+/* Supports the MEM_REF offset.
+   _1 = MEM[(struct arc *)ap_4 + 72B].flow;
+   Old rewrite：_1 = ap.reorder.0_8->flow;
+   New rewrite：_1 = MEM[(struct arc.reorder.0 *)ap.reorder.0_8 + 64B].flow.  */
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node node_t;
+typedef struct node *node_p;
+
+typedef struct arc arc_t;
+typedef struct arc *arc_p;
+
+struct node
+{
+  int64_t potential;
+  int orientation;
+  node_p child;
+  node_p pred;
+  node_p sibling;
+  node_p sibling_prev;
+  arc_p basic_arc;
+  arc_p firstout;
+  arc_p firstin;
+  arc_p arc_tmp;
+  int64_t flow;
+  int64_t depth;
+  int number;
+  int time;
+};
+
+struct arc
+{
+  int id;
+  int64_t cost;
+  node_p tail;
+  node_p head;
+  short ident;
+  arc_p nextout;
+  arc_p nextin;
+  int64_t flow;
+  int64_t org_cost;
+};
+
+int
+main ()
+{
+  const int MAX = 100;
+  /* A similar scenario can be reproduced only by using local variables.  */
+  arc_p ap = NULL;
+  ap = (arc_p) calloc(MAX, sizeof(arc_t));
+  printf("%d\n", ap[1].flow);
+  return 0; 
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 2 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_mul_layer_ptr_record_bug.c b/gcc/testsuite/gcc.dg/struct/dfe_mul_layer_ptr_record_bug.c
new file mode 100644
index 000000000..fd675ec2e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_mul_layer_ptr_record_bug.c
@@ -0,0 +1,30 @@
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct T_HASH_ENTRY
+{ 
+  unsigned int hash;
+  unsigned int klen;
+  char *key;
+} iHashEntry;
+
+typedef struct T_HASH
+{
+  unsigned int size;
+  unsigned int fill;
+  unsigned int keys;
+
+  iHashEntry **array;
+} uHash;
+
+uHash *retval;
+
+int
+main() {
+  retval->array = (iHashEntry **)calloc(sizeof(iHashEntry *), retval->size);
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 2 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_ptr_diff.c b/gcc/testsuite/gcc.dg/struct/dfe_ptr_diff.c
new file mode 100644
index 000000000..600e7908b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_ptr_diff.c
@@ -0,0 +1,71 @@
+// support POINTER_DIFF_EXPR & NOP_EXPR to avoid 
+// escape_unhandled_rewrite, "Type escapes via a unhandled rewrite stmt"
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node node_t;
+typedef struct node *node_p;
+
+typedef struct arc arc_t;
+typedef struct arc *arc_p;
+
+typedef struct network
+{    
+  arc_p arcs;
+  arc_p sorted_arcs;
+  int x;
+  node_p nodes;
+  node_p stop_nodes;
+} network_t;
+
+struct node
+{
+  int64_t potential;
+  int orientation;
+  node_p child;
+  node_p pred;
+  node_p sibling;
+  node_p sibling_prev;
+  arc_p basic_arc;
+  arc_p firstout;
+  arc_p firstin;
+  arc_p arc_tmp;
+  int64_t flow;
+  int64_t depth;
+  int number;
+  int time;
+};
+
+struct arc
+{
+  int id;
+  int64_t cost;
+  node_p tail;
+  node_p head;
+  short ident;
+  arc_p nextout;
+  arc_p nextin;
+  int64_t flow;
+  int64_t org_cost;
+};
+
+int
+main ()
+{
+  arc_t *old_arcs;
+  node_t *node;
+  node_t *stop;
+  size_t off;
+  network_t* net;
+
+  for( ; node->number < stop->number; node++ )
+    {
+      off = node->basic_arc - old_arcs;
+      node->basic_arc = (arc_t *)(net->arcs + off);
+    }
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 3 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_ptr_negate_expr.c b/gcc/testsuite/gcc.dg/struct/dfe_ptr_negate_expr.c
new file mode 100644
index 000000000..f411364a7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_ptr_negate_expr.c
@@ -0,0 +1,55 @@
+// support NEGATE_EXPR rewriting
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node node_t;
+typedef struct node *node_p;
+
+typedef struct arc arc_t;
+typedef struct arc *arc_p;
+
+struct node
+{
+  int64_t potential;
+  int orientation;
+  node_p child;
+  node_p pred;
+  node_p sibling;
+  node_p sibling_prev;
+  arc_p basic_arc;
+  arc_p firstout;
+  arc_p firstin;
+  arc_p arc_tmp;
+  int64_t flow;
+  int64_t depth;
+  int number;
+  int time;
+};
+
+struct arc
+{
+  int id;
+  int64_t cost;
+  node_p tail;
+  node_p head;
+  short ident;
+  arc_p nextout;
+  arc_p nextin;
+  int64_t flow;
+  int64_t org_cost;
+};
+
+int
+main ()
+{
+  int64_t susp = 0;
+  const int MAX = 100;
+  arc_p ap = (arc_p) calloc(MAX, sizeof(arc_t));
+  ap -= susp;
+  printf("%d\n", ap[1].flow);
+  return 0; 
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 2 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/dfe_ptr_ptr.c b/gcc/testsuite/gcc.dg/struct/dfe_ptr_ptr.c
new file mode 100644
index 000000000..a4e723763
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/struct/dfe_ptr_ptr.c
@@ -0,0 +1,55 @@
+// release escape_ptr_ptr, "Type is used in a pointer to a pointer [not handled yet]";
+/* { dg-do compile } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node node_t;
+typedef struct node *node_p;
+
+typedef struct arc arc_t;
+typedef struct arc *arc_p;
+
+struct node
+{
+  int64_t potential;
+  int orientation;
+  node_p child;
+  node_p pred;
+  node_p sibling;
+  node_p sibling_prev;
+  arc_p basic_arc;
+  arc_p firstout;
+  arc_p firstin;
+  arc_p arc_tmp;
+  int64_t flow;
+  int64_t depth;
+  int number;
+  int time;
+};
+
+struct arc
+{
+  int id;
+  int64_t cost;
+  node_p tail;
+  node_p head;
+  short ident;
+  arc_p nextout;
+  arc_p nextin;
+  int64_t flow;
+  int64_t org_cost;
+};
+
+const int MAX = 100;
+arc_t **ap = NULL;
+
+int
+main ()
+{
+  ap = (arc_t**) malloc(MAX * sizeof(arc_t*));
+  (*ap)[0].id = 300;
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump-times "Dead field elimination" 2 "struct_layout" } } */
diff --git a/gcc/testsuite/gcc.dg/struct/struct-reorg.exp b/gcc/testsuite/gcc.dg/struct/struct-reorg.exp
index 67b3ac2d5..ac5585813 100644
--- a/gcc/testsuite/gcc.dg/struct/struct-reorg.exp
+++ b/gcc/testsuite/gcc.dg/struct/struct-reorg.exp
@@ -64,8 +64,27 @@ gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/complete_struct_relayout
 	"" "-fipa-struct-reorg=1 -fdump-ipa-all -flto-partition=one -fwhole-program"
 
 # -fipa-struct-reorg=2
-gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.c]] \
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/rf*.c]] \
+ 	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/wo_prof_*.c]] \
  	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/w_ratio_*.c]] \
+	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/w_prof_*.c]] \
+	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/struct_reorg*.c]] \
+	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/sr_*.c]] \
+	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/csr_*.c]] \
+	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/complete_struct_relayout.c]] \
+	"" "-fipa-struct-reorg=2 -fdump-ipa-all -flto-partition=one -fwhole-program"
+
+# -fipa-struct-reorg=3
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/dfe*.c]] \
+	"" "-fipa-struct-reorg=3 -fdump-ipa-all -flto-partition=one -fwhole-program"
+
 # All done.
 torture-finish
 dg-finish
-- 
2.27.0.windows.1