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[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-pre.c
index 5da6c63..727614a 100644 (file)
@@ -1,5 +1,5 @@
 /* SSA-PRE for trees.
-   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
    Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
    <stevenb@suse.de>
@@ -24,10 +24,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
-#include "ggc.h"
 #include "tree.h"
 #include "basic-block.h"
-#include "diagnostic.h"
+#include "tree-pretty-print.h"
+#include "gimple-pretty-print.h"
 #include "tree-inline.h"
 #include "tree-flow.h"
 #include "gimple.h"
@@ -36,7 +36,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "fibheap.h"
 #include "hashtab.h"
 #include "tree-iterator.h"
-#include "real.h"
 #include "alloc-pool.h"
 #include "obstack.h"
 #include "tree-pass.h"
@@ -204,7 +203,7 @@ pre_expr_eq (const void *p1, const void *p2)
       return vn_reference_eq (PRE_EXPR_REFERENCE (e1),
                              PRE_EXPR_REFERENCE (e2));
     default:
-      abort();
+      gcc_unreachable ();
     }
 }
 
@@ -217,13 +216,13 @@ pre_expr_hash (const void *p1)
     case CONSTANT:
       return vn_hash_constant_with_type (PRE_EXPR_CONSTANT (e));
     case NAME:
-      return iterative_hash_hashval_t (SSA_NAME_VERSION (PRE_EXPR_NAME (e)), 0);
+      return SSA_NAME_VERSION (PRE_EXPR_NAME (e));
     case NARY:
       return PRE_EXPR_NARY (e)->hashcode;
     case REFERENCE:
       return PRE_EXPR_REFERENCE (e)->hashcode;
     default:
-      abort ();
+      gcc_unreachable ();
     }
 }
 
@@ -236,6 +235,7 @@ DEF_VEC_P (pre_expr);
 DEF_VEC_ALLOC_P (pre_expr, heap);
 static VEC(pre_expr, heap) *expressions;
 static htab_t expression_to_id;
+static VEC(unsigned, heap) *name_to_id;
 
 /* Allocate an expression id for EXPR.  */
 
@@ -247,9 +247,23 @@ alloc_expression_id (pre_expr expr)
   gcc_assert (next_expression_id + 1 > next_expression_id);
   expr->id = next_expression_id++;
   VEC_safe_push (pre_expr, heap, expressions, expr);
-  slot = htab_find_slot (expression_to_id, expr, INSERT);
-  gcc_assert (!*slot);
-  *slot = expr;
+  if (expr->kind == NAME)
+    {
+      unsigned version = SSA_NAME_VERSION (PRE_EXPR_NAME (expr));
+      /* VEC_safe_grow_cleared allocates no headroom.  Avoid frequent
+        re-allocations by using VEC_reserve upfront.  There is no
+        VEC_quick_grow_cleared unfortunately.  */
+      VEC_reserve (unsigned, heap, name_to_id, num_ssa_names);
+      VEC_safe_grow_cleared (unsigned, heap, name_to_id, num_ssa_names);
+      gcc_assert (VEC_index (unsigned, name_to_id, version) == 0);
+      VEC_replace (unsigned, name_to_id, version, expr->id);
+    }
+  else
+    {
+      slot = htab_find_slot (expression_to_id, expr, INSERT);
+      gcc_assert (!*slot);
+      *slot = expr;
+    }
   return next_expression_id - 1;
 }
 
@@ -266,10 +280,20 @@ lookup_expression_id (const pre_expr expr)
 {
   void **slot;
 
-  slot = htab_find_slot (expression_to_id, expr, NO_INSERT);
-  if (!slot)
-    return 0;
-  return ((pre_expr)*slot)->id;
+  if (expr->kind == NAME)
+    {
+      unsigned version = SSA_NAME_VERSION (PRE_EXPR_NAME (expr));
+      if (VEC_length (unsigned, name_to_id) <= version)
+       return 0;
+      return VEC_index (unsigned, name_to_id, version);
+    }
+  else
+    {
+      slot = htab_find_slot (expression_to_id, expr, NO_INSERT);
+      if (!slot)
+       return 0;
+      return ((pre_expr)*slot)->id;
+    }
 }
 
 /* Return the existing expression id for EXPR, or create one if one
@@ -308,20 +332,21 @@ static alloc_pool pre_expr_pool;
 static pre_expr
 get_or_alloc_expr_for_name (tree name)
 {
-  pre_expr result = (pre_expr) pool_alloc (pre_expr_pool);
+  struct pre_expr_d expr;
+  pre_expr result;
   unsigned int result_id;
 
+  expr.kind = NAME;
+  expr.id = 0;
+  PRE_EXPR_NAME (&expr) = name;
+  result_id = lookup_expression_id (&expr);
+  if (result_id != 0)
+    return expression_for_id (result_id);
+
+  result = (pre_expr) pool_alloc (pre_expr_pool);
   result->kind = NAME;
-  result->id = 0;
   PRE_EXPR_NAME (result) = name;
-  result_id = lookup_expression_id (result);
-  if (result_id != 0)
-    {
-      pool_free (pre_expr_pool, result);
-      result = expression_for_id (result_id);
-      return result;
-    }
-  get_or_alloc_expression_id (result);
+  alloc_expression_id (result);
   return result;
 }
 
@@ -331,15 +356,15 @@ static bool in_fre = false;
    expressions.  */
 typedef struct bitmap_set
 {
-  bitmap expressions;
-  bitmap values;
+  bitmap_head expressions;
+  bitmap_head values;
 } *bitmap_set_t;
 
 #define FOR_EACH_EXPR_ID_IN_SET(set, id, bi)           \
-  EXECUTE_IF_SET_IN_BITMAP((set)->expressions, 0, (id), (bi))
+  EXECUTE_IF_SET_IN_BITMAP(&(set)->expressions, 0, (id), (bi))
 
 #define FOR_EACH_VALUE_ID_IN_SET(set, id, bi)          \
-  EXECUTE_IF_SET_IN_BITMAP((set)->values, 0, (id), (bi))
+  EXECUTE_IF_SET_IN_BITMAP(&(set)->values, 0, (id), (bi))
 
 /* Mapping from value id to expressions with that value_id.  */
 DEF_VEC_P (bitmap_set_t);
@@ -382,11 +407,14 @@ typedef struct bb_bitmap_sets
   bitmap expr_dies;
 
   /* True if we have visited this block during ANTIC calculation.  */
-  unsigned int visited:1;
+  unsigned int visited : 1;
 
   /* True we have deferred processing this block during ANTIC
      calculation until its successor is processed.  */
   unsigned int deferred : 1;
+
+  /* True when the block contains a call that might not return.  */
+  unsigned int contains_may_not_return_call : 1;
 } *bb_value_sets_t;
 
 #define EXP_GEN(BB)    ((bb_value_sets_t) ((BB)->aux))->exp_gen
@@ -399,6 +427,7 @@ typedef struct bb_bitmap_sets
 #define EXPR_DIES(BB)  ((bb_value_sets_t) ((BB)->aux))->expr_dies
 #define BB_VISITED(BB) ((bb_value_sets_t) ((BB)->aux))->visited
 #define BB_DEFERRED(BB) ((bb_value_sets_t) ((BB)->aux))->deferred
+#define BB_MAY_NOTRETURN(BB) ((bb_value_sets_t) ((BB)->aux))->contains_may_not_return_call
 
 
 /* Basic block list in postorder.  */
@@ -419,10 +448,6 @@ static struct
 
   /* The number of new PHI nodes added by PRE.  */
   int phis;
-
-  /* The number of values found constant.  */
-  int constified;
-
 } pre_stats;
 
 static bool do_partial_partial;
@@ -432,7 +457,8 @@ static void bitmap_value_replace_in_set (bitmap_set_t, pre_expr);
 static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
 static bool bitmap_set_contains_value (bitmap_set_t, unsigned int);
 static void bitmap_insert_into_set (bitmap_set_t, pre_expr);
-static void bitmap_insert_into_set_1 (bitmap_set_t, pre_expr, bool);
+static void bitmap_insert_into_set_1 (bitmap_set_t, pre_expr,
+                                     unsigned int, bool);
 static bitmap_set_t bitmap_set_new (void);
 static tree create_expression_by_pieces (basic_block, pre_expr, gimple_seq *,
                                         gimple, tree);
@@ -454,12 +480,11 @@ static tree pretemp;
 static tree storetemp;
 static tree prephitemp;
 
-/* Set of blocks with statements that have had its EH information
-   cleaned up.  */
+/* Set of blocks with statements that have had their EH properties changed.  */
 static bitmap need_eh_cleanup;
 
-/* Which expressions have been seen during a given phi translation.  */
-static bitmap seen_during_translate;
+/* Set of blocks with statements that have had their AB properties changed.  */
+static bitmap need_ab_cleanup;
 
 /* The phi_translate_table caches phi translations for a given
    expression and predecessor.  */
@@ -551,8 +576,7 @@ phi_trans_add (pre_expr e, pre_expr v, basic_block pred)
 
   slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
                                   new_pair->hashcode, INSERT);
-  if (*slot)
-    free (*slot);
+  free (*slot);
   *slot = (void *) new_pair;
 }
 
@@ -579,7 +603,7 @@ add_to_value (unsigned int v, pre_expr e)
       VEC_replace (bitmap_set_t, value_expressions, v, set);
     }
 
-  bitmap_insert_into_set_1 (set, e, true);
+  bitmap_insert_into_set_1 (set, e, v, true);
 }
 
 /* Create a new bitmap set and return it.  */
@@ -588,8 +612,8 @@ static bitmap_set_t
 bitmap_set_new (void)
 {
   bitmap_set_t ret = (bitmap_set_t) pool_alloc (bitmap_set_pool);
-  ret->expressions = BITMAP_ALLOC (&grand_bitmap_obstack);
-  ret->values = BITMAP_ALLOC (&grand_bitmap_obstack);
+  bitmap_initialize (&ret->expressions, &grand_bitmap_obstack);
+  bitmap_initialize (&ret->values, &grand_bitmap_obstack);
   return ret;
 }
 
@@ -630,22 +654,21 @@ bitmap_remove_from_set (bitmap_set_t set, pre_expr expr)
   unsigned int val  = get_expr_value_id (expr);
   if (!value_id_constant_p (val))
     {
-      bitmap_clear_bit (set->values, val);
-      bitmap_clear_bit (set->expressions, get_expression_id (expr));
+      bitmap_clear_bit (&set->values, val);
+      bitmap_clear_bit (&set->expressions, get_expression_id (expr));
     }
 }
 
 static void
 bitmap_insert_into_set_1 (bitmap_set_t set, pre_expr expr,
-                         bool allow_constants)
+                         unsigned int val, bool allow_constants)
 {
-  unsigned int val  = get_expr_value_id (expr);
   if (allow_constants || !value_id_constant_p (val))
     {
       /* We specifically expect this and only this function to be able to
         insert constants into a set.  */
-      bitmap_set_bit (set->values, val);
-      bitmap_set_bit (set->expressions, get_or_alloc_expression_id (expr));
+      bitmap_set_bit (&set->values, val);
+      bitmap_set_bit (&set->expressions, get_or_alloc_expression_id (expr));
     }
 }
 
@@ -654,7 +677,7 @@ bitmap_insert_into_set_1 (bitmap_set_t set, pre_expr expr,
 static void
 bitmap_insert_into_set (bitmap_set_t set, pre_expr expr)
 {
-  bitmap_insert_into_set_1 (set, expr, false);
+  bitmap_insert_into_set_1 (set, expr, get_expr_value_id (expr), false);
 }
 
 /* Copy a bitmapped set ORIG, into bitmapped set DEST.  */
@@ -662,8 +685,8 @@ bitmap_insert_into_set (bitmap_set_t set, pre_expr expr)
 static void
 bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
 {
-  bitmap_copy (dest->expressions, orig->expressions);
-  bitmap_copy (dest->values, orig->values);
+  bitmap_copy (&dest->expressions, &orig->expressions);
+  bitmap_copy (&dest->values, &orig->values);
 }
 
 
@@ -671,8 +694,8 @@ bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
 static void
 bitmap_set_free (bitmap_set_t set)
 {
-  BITMAP_FREE (set->expressions);
-  BITMAP_FREE (set->values);
+  bitmap_clear (&set->expressions);
+  bitmap_clear (&set->values);
 }
 
 
@@ -683,7 +706,10 @@ sorted_array_from_bitmap_set (bitmap_set_t set)
 {
   unsigned int i, j;
   bitmap_iterator bi, bj;
-  VEC(pre_expr, heap) *result = NULL;
+  VEC(pre_expr, heap) *result;
+
+  /* Pre-allocate roughly enough space for the array.  */
+  result = VEC_alloc (pre_expr, heap, bitmap_count_bits (&set->values));
 
   FOR_EACH_VALUE_ID_IN_SET (set, i, bi)
     {
@@ -700,7 +726,7 @@ sorted_array_from_bitmap_set (bitmap_set_t set)
       bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, i);
       FOR_EACH_EXPR_ID_IN_SET (exprset, j, bj)
        {
-         if (bitmap_bit_p (set->expressions, j))
+         if (bitmap_bit_p (&set->expressions, j))
            VEC_safe_push (pre_expr, heap, result, expression_for_id (j));
         }
     }
@@ -718,18 +744,19 @@ bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig)
 
   if (dest != orig)
     {
-      bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
+      bitmap_head temp;
+      bitmap_initialize (&temp, &grand_bitmap_obstack);
 
-      bitmap_and_into (dest->values, orig->values);
-      bitmap_copy (temp, dest->expressions);
-      EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
+      bitmap_and_into (&dest->values, &orig->values);
+      bitmap_copy (&temp, &dest->expressions);
+      EXECUTE_IF_SET_IN_BITMAP (&temp, 0, i, bi)
        {
          pre_expr expr = expression_for_id (i);
          unsigned int value_id = get_expr_value_id (expr);
-         if (!bitmap_bit_p (dest->values, value_id))
-           bitmap_clear_bit (dest->expressions, i);
+         if (!bitmap_bit_p (&dest->values, value_id))
+           bitmap_clear_bit (&dest->expressions, i);
        }
-      BITMAP_FREE (temp);
+      bitmap_clear (&temp);
     }
 }
 
@@ -742,14 +769,14 @@ bitmap_set_subtract (bitmap_set_t dest, bitmap_set_t orig)
   bitmap_iterator bi;
   unsigned int i;
 
-  bitmap_and_compl (result->expressions, dest->expressions,
-                   orig->expressions);
+  bitmap_and_compl (&result->expressions, &dest->expressions,
+                   &orig->expressions);
 
   FOR_EACH_EXPR_ID_IN_SET (result, i, bi)
     {
       pre_expr expr = expression_for_id (i);
       unsigned int value_id = get_expr_value_id (expr);
-      bitmap_set_bit (result->values, value_id);
+      bitmap_set_bit (&result->values, value_id);
     }
 
   return result;
@@ -762,16 +789,18 @@ bitmap_set_subtract_values (bitmap_set_t a, bitmap_set_t b)
 {
   unsigned int i;
   bitmap_iterator bi;
-  bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
+  bitmap_head temp;
 
-  bitmap_copy (temp, a->expressions);
-  EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
+  bitmap_initialize (&temp, &grand_bitmap_obstack);
+
+  bitmap_copy (&temp, &a->expressions);
+  EXECUTE_IF_SET_IN_BITMAP (&temp, 0, i, bi)
     {
       pre_expr expr = expression_for_id (i);
       if (bitmap_set_contains_value (b, get_expr_value_id (expr)))
        bitmap_remove_from_set (a, expr);
     }
-  BITMAP_FREE (temp);
+  bitmap_clear (&temp);
 }
 
 
@@ -783,16 +812,16 @@ bitmap_set_contains_value (bitmap_set_t set, unsigned int value_id)
   if (value_id_constant_p (value_id))
     return true;
 
-  if (!set || bitmap_empty_p (set->expressions))
+  if (!set || bitmap_empty_p (&set->expressions))
     return false;
 
-  return bitmap_bit_p (set->values, value_id);
+  return bitmap_bit_p (&set->values, value_id);
 }
 
 static inline bool
 bitmap_set_contains_expr (bitmap_set_t set, const pre_expr expr)
 {
-  return bitmap_bit_p (set->expressions, get_expression_id (expr));
+  return bitmap_bit_p (&set->expressions, get_expression_id (expr));
 }
 
 /* Replace an instance of value LOOKFOR with expression EXPR in SET.  */
@@ -823,13 +852,14 @@ bitmap_set_replace_value (bitmap_set_t set, unsigned int lookfor,
   exprset = VEC_index (bitmap_set_t, value_expressions, lookfor);
   FOR_EACH_EXPR_ID_IN_SET (exprset, i, bi)
     {
-      if (bitmap_bit_p (set->expressions, i))
+      if (bitmap_clear_bit (&set->expressions, i))
        {
-         bitmap_clear_bit (set->expressions, i);
-         bitmap_set_bit (set->expressions, get_expression_id (expr));
+         bitmap_set_bit (&set->expressions, get_expression_id (expr));
          return;
        }
     }
+
+  gcc_unreachable ();
 }
 
 /* Return true if two bitmap sets are equal.  */
@@ -837,7 +867,7 @@ bitmap_set_replace_value (bitmap_set_t set, unsigned int lookfor,
 static bool
 bitmap_set_equal (bitmap_set_t a, bitmap_set_t b)
 {
-  return bitmap_equal_p (a->values, b->values);
+  return bitmap_equal_p (&a->values, &b->values);
 }
 
 /* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
@@ -862,11 +892,15 @@ bitmap_value_insert_into_set (bitmap_set_t set, pre_expr expr)
 {
   unsigned int val = get_expr_value_id (expr);
 
+  gcc_checking_assert (expr->id == get_or_alloc_expression_id (expr));
+
+  /* Constant values are always considered to be part of the set.  */
   if (value_id_constant_p (val))
     return;
 
-  if (!bitmap_set_contains_value (set, val))
-    bitmap_insert_into_set (set, expr);
+  /* If the value membership changed, add the expression.  */
+  if (bitmap_set_bit (&set->values, val))
+    bitmap_set_bit (&set->expressions, expr->id);
 }
 
 /* Print out EXPR to outfile.  */
@@ -950,7 +984,7 @@ print_pre_expr (FILE *outfile, const pre_expr expr)
 void debug_pre_expr (pre_expr);
 
 /* Like print_pre_expr but always prints to stderr.  */
-void
+DEBUG_FUNCTION void
 debug_pre_expr (pre_expr e)
 {
   print_pre_expr (stderr, e);
@@ -987,7 +1021,7 @@ print_bitmap_set (FILE *outfile, bitmap_set_t set,
 
 void debug_bitmap_set (bitmap_set_t);
 
-void
+DEBUG_FUNCTION void
 debug_bitmap_set (bitmap_set_t set)
 {
   print_bitmap_set (stderr, set, "debug", 0);
@@ -1008,7 +1042,7 @@ print_value_expressions (FILE *outfile, unsigned int val)
 }
 
 
-void
+DEBUG_FUNCTION void
 debug_value_expressions (unsigned int val)
 {
   print_value_expressions (stderr, val);
@@ -1022,18 +1056,20 @@ get_or_alloc_expr_for_constant (tree constant)
 {
   unsigned int result_id;
   unsigned int value_id;
-  pre_expr newexpr = (pre_expr) pool_alloc (pre_expr_pool);
+  struct pre_expr_d expr;
+  pre_expr newexpr;
+
+  expr.kind = CONSTANT;
+  PRE_EXPR_CONSTANT (&expr) = constant;
+  result_id = lookup_expression_id (&expr);
+  if (result_id != 0)
+    return expression_for_id (result_id);
+
+  newexpr = (pre_expr) pool_alloc (pre_expr_pool);
   newexpr->kind = CONSTANT;
   PRE_EXPR_CONSTANT (newexpr) = constant;
-  result_id = lookup_expression_id (newexpr);
-  if (result_id != 0)
-    {
-      pool_free (pre_expr_pool, newexpr);
-      newexpr = expression_for_id (result_id);
-      return newexpr;
-    }
+  alloc_expression_id (newexpr);
   value_id = get_or_alloc_constant_value_id (constant);
-  get_or_alloc_expression_id (newexpr);
   add_to_value (value_id, newexpr);
   return newexpr;
 }
@@ -1112,14 +1148,6 @@ fully_constant_expression (pre_expr e)
        vn_nary_op_t nary = PRE_EXPR_NARY (e);
        switch (TREE_CODE_CLASS (nary->opcode))
          {
-         case tcc_expression:
-           if (nary->opcode == TRUTH_NOT_EXPR)
-             goto do_unary;
-           if (nary->opcode != TRUTH_AND_EXPR
-               && nary->opcode != TRUTH_OR_EXPR
-               && nary->opcode != TRUTH_XOR_EXPR)
-             return e;
-           /* Fallthrough.  */
          case tcc_binary:
          case tcc_comparison:
            {
@@ -1156,12 +1184,11 @@ fully_constant_expression (pre_expr e)
            }
          case tcc_reference:
            if (nary->opcode != REALPART_EXPR
-               && nary->opcode != IMAGPART_EXPR 
+               && nary->opcode != IMAGPART_EXPR
                && nary->opcode != VIEW_CONVERT_EXPR)
              return e;
            /* Fallthrough.  */
          case tcc_unary:
-do_unary:
            {
              /* We have to go from trees to pre exprs to value ids to
                 constants.  */
@@ -1193,49 +1220,11 @@ do_unary:
     case REFERENCE:
       {
        vn_reference_t ref = PRE_EXPR_REFERENCE (e);
-       VEC (vn_reference_op_s, heap) *operands = ref->operands;
-       vn_reference_op_t op;
-
-       /* Try to simplify the translated expression if it is
-          a call to a builtin function with at most two arguments.  */
-       op = VEC_index (vn_reference_op_s, operands, 0);
-       if (op->opcode == CALL_EXPR
-           && TREE_CODE (op->op0) == ADDR_EXPR
-           && TREE_CODE (TREE_OPERAND (op->op0, 0)) == FUNCTION_DECL
-           && DECL_BUILT_IN (TREE_OPERAND (op->op0, 0))
-           && VEC_length (vn_reference_op_s, operands) >= 2
-           && VEC_length (vn_reference_op_s, operands) <= 3)
-         {
-           vn_reference_op_t arg0, arg1 = NULL;
-           bool anyconst = false;
-           arg0 = VEC_index (vn_reference_op_s, operands, 1);
-           if (VEC_length (vn_reference_op_s, operands) > 2)
-             arg1 = VEC_index (vn_reference_op_s, operands, 2);
-           if (TREE_CODE_CLASS (arg0->opcode) == tcc_constant
-               || (arg0->opcode == ADDR_EXPR
-                   && is_gimple_min_invariant (arg0->op0)))
-             anyconst = true;
-           if (arg1
-               && (TREE_CODE_CLASS (arg1->opcode) == tcc_constant
-                   || (arg1->opcode == ADDR_EXPR
-                       && is_gimple_min_invariant (arg1->op0))))
-             anyconst = true;
-           if (anyconst)
-             {
-               tree folded = build_call_expr (TREE_OPERAND (op->op0, 0),
-                                              arg1 ? 2 : 1,
-                                              arg0->op0,
-                                              arg1 ? arg1->op0 : NULL);
-               if (folded
-                   && TREE_CODE (folded) == NOP_EXPR)
-                 folded = TREE_OPERAND (folded, 0);
-               if (folded
-                   && is_gimple_min_invariant (folded))
-                 return get_or_alloc_expr_for_constant (folded);
-             }
-         }
-         return e;
-       }
+       tree folded;
+       if ((folded = fully_constant_vn_reference_p (ref)))
+         return get_or_alloc_expr_for_constant (folded);
+       return e;
+      }
     default:
       return e;
     }
@@ -1243,43 +1232,74 @@ do_unary:
 }
 
 /* Translate the VUSE backwards through phi nodes in PHIBLOCK, so that
-   it has the value it would have in BLOCK.  */
+   it has the value it would have in BLOCK.  Set *SAME_VALID to true
+   in case the new vuse doesn't change the value id of the OPERANDS.  */
 
 static tree
 translate_vuse_through_block (VEC (vn_reference_op_s, heap) *operands,
                              alias_set_type set, tree type, tree vuse,
                              basic_block phiblock,
-                             basic_block block)
+                             basic_block block, bool *same_valid)
 {
   gimple phi = SSA_NAME_DEF_STMT (vuse);
   ao_ref ref;
+  edge e = NULL;
+  bool use_oracle;
+
+  *same_valid = true;
 
   if (gimple_bb (phi) != phiblock)
     return vuse;
 
-  if (gimple_code (phi) == GIMPLE_PHI)
-    {
-      edge e = find_edge (block, phiblock);
-      return PHI_ARG_DEF (phi, e->dest_idx);
-    }
-
-  if (!ao_ref_init_from_vn_reference (&ref, set, type, operands))
-    return NULL_TREE;
+  use_oracle = ao_ref_init_from_vn_reference (&ref, set, type, operands);
 
   /* Use the alias-oracle to find either the PHI node in this block,
      the first VUSE used in this block that is equivalent to vuse or
      the first VUSE which definition in this block kills the value.  */
-  while (!stmt_may_clobber_ref_p_1 (phi, &ref))
+  if (gimple_code (phi) == GIMPLE_PHI)
+    e = find_edge (block, phiblock);
+  else if (use_oracle)
+    while (!stmt_may_clobber_ref_p_1 (phi, &ref))
+      {
+       vuse = gimple_vuse (phi);
+       phi = SSA_NAME_DEF_STMT (vuse);
+       if (gimple_bb (phi) != phiblock)
+         return vuse;
+       if (gimple_code (phi) == GIMPLE_PHI)
+         {
+           e = find_edge (block, phiblock);
+           break;
+         }
+      }
+  else
+    return NULL_TREE;
+
+  if (e)
     {
-      vuse = gimple_vuse (phi);
-      phi = SSA_NAME_DEF_STMT (vuse);
-      if (gimple_bb (phi) != phiblock)
-       return vuse;
-      if (gimple_code (phi) == GIMPLE_PHI)
+      if (use_oracle)
+       {
+         bitmap visited = NULL;
+         /* Try to find a vuse that dominates this phi node by skipping
+            non-clobbering statements.  */
+         vuse = get_continuation_for_phi (phi, &ref, &visited, false);
+         if (visited)
+           BITMAP_FREE (visited);
+       }
+      else
+       vuse = NULL_TREE;
+      if (!vuse)
        {
-         edge e = find_edge (block, phiblock);
-         return PHI_ARG_DEF (phi, e->dest_idx);
+         /* If we didn't find any, the value ID can't stay the same,
+            but return the translated vuse.  */
+         *same_valid = false;
+         vuse = PHI_ARG_DEF (phi, e->dest_idx);
        }
+      /* ??? We would like to return vuse here as this is the canonical
+         upmost vdef that this reference is associated with.  But during
+        insertion of the references into the hash tables we only ever
+        directly insert with their direct gimple_vuse, hence returning
+        something else would make us not find the other expression.  */
+      return PHI_ARG_DEF (phi, e->dest_idx);
     }
 
   return NULL_TREE;
@@ -1376,8 +1396,8 @@ get_representative_for (const pre_expr e)
      that we will return.  */
   if (!pretemp || exprtype != TREE_TYPE (pretemp))
     {
-      pretemp = create_tmp_var (exprtype, "pretmp");
-      get_var_ann (pretemp);
+      pretemp = create_tmp_reg (exprtype, "pretmp");
+      add_referenced_var (pretemp);
     }
 
   name = make_ssa_name (pretemp, gimple_build_nop ());
@@ -1402,101 +1422,68 @@ get_representative_for (const pre_expr e)
 
 
 
+static pre_expr
+phi_translate (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
+              basic_block pred, basic_block phiblock);
 
 /* Translate EXPR using phis in PHIBLOCK, so that it has the values of
-   the phis in PRED.  SEEN is a bitmap saying which expression we have
-   translated since we started translation of the toplevel expression.
-   Return NULL if we can't find a leader for each part of the
-   translated expression.  */
+   the phis in PRED.  Return NULL if we can't find a leader for each part
+   of the translated expression.  */
 
 static pre_expr
 phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
-                basic_block pred, basic_block phiblock, bitmap seen)
+                basic_block pred, basic_block phiblock)
 {
-  pre_expr oldexpr = expr;
-  pre_expr phitrans;
-
-  if (!expr)
-    return NULL;
-
-  if (value_id_constant_p (get_expr_value_id (expr)))
-    return expr;
-
-  phitrans = phi_trans_lookup (expr, pred);
-  if (phitrans)
-    return phitrans;
-
-  /* Prevent cycles when we have recursively dependent leaders.  This
-     can only happen when phi translating the maximal set.  */
-  if (seen)
-    {
-      unsigned int expr_id = get_expression_id (expr);
-      if (bitmap_bit_p (seen, expr_id))
-       return NULL;
-      bitmap_set_bit (seen, expr_id);
-    }
-
   switch (expr->kind)
     {
-      /* Constants contain no values that need translation.  */
-    case CONSTANT:
-      return expr;
-
     case NARY:
       {
        unsigned int i;
        bool changed = false;
        vn_nary_op_t nary = PRE_EXPR_NARY (expr);
-       struct vn_nary_op_s newnary;
-       /* The NARY structure is only guaranteed to have been
-          allocated to the nary->length operands.  */
-       memcpy (&newnary, nary, (sizeof (struct vn_nary_op_s)
-                                - sizeof (tree) * (4 - nary->length)));
+       vn_nary_op_t newnary = XALLOCAVAR (struct vn_nary_op_s,
+                                          sizeof_vn_nary_op (nary->length));
+       memcpy (newnary, nary, sizeof_vn_nary_op (nary->length));
 
-       for (i = 0; i < newnary.length; i++)
+       for (i = 0; i < newnary->length; i++)
          {
-           if (TREE_CODE (newnary.op[i]) != SSA_NAME)
+           if (TREE_CODE (newnary->op[i]) != SSA_NAME)
              continue;
            else
              {
-               unsigned int op_val_id = VN_INFO (newnary.op[i])->value_id;
-               pre_expr leader = find_leader_in_sets (op_val_id, set1, set2);
-               pre_expr result = phi_translate_1 (leader, set1, set2,
-                                                  pred, phiblock, seen);
+                pre_expr leader, result;
+               unsigned int op_val_id = VN_INFO (newnary->op[i])->value_id;
+               leader = find_leader_in_sets (op_val_id, set1, set2);
+                result = phi_translate (leader, set1, set2, pred, phiblock);
                if (result && result != leader)
                  {
                    tree name = get_representative_for (result);
                    if (!name)
                      return NULL;
-                   newnary.op[i] = name;
+                   newnary->op[i] = name;
                  }
                else if (!result)
                  return NULL;
 
-               changed |= newnary.op[i] != nary->op[i];
+               changed |= newnary->op[i] != nary->op[i];
              }
          }
        if (changed)
          {
            pre_expr constant;
+           unsigned int new_val_id;
 
-           tree result = vn_nary_op_lookup_pieces (newnary.length,
-                                                   newnary.opcode,
-                                                   newnary.type,
-                                                   newnary.op[0],
-                                                   newnary.op[1],
-                                                   newnary.op[2],
-                                                   newnary.op[3],
+           tree result = vn_nary_op_lookup_pieces (newnary->length,
+                                                   newnary->opcode,
+                                                   newnary->type,
+                                                   &newnary->op[0],
                                                    &nary);
-           unsigned int new_val_id;
+           if (result && is_gimple_min_invariant (result))
+             return get_or_alloc_expr_for_constant (result);
 
            expr = (pre_expr) pool_alloc (pre_expr_pool);
            expr->kind = NARY;
            expr->id = 0;
-           if (result && is_gimple_min_invariant (result))
-             return get_or_alloc_expr_for_constant (result);
-
-
            if (nary)
              {
                PRE_EXPR_NARY (expr) = nary;
@@ -1513,13 +1500,10 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
                VEC_safe_grow_cleared (bitmap_set_t, heap,
                                       value_expressions,
                                       get_max_value_id() + 1);
-               nary = vn_nary_op_insert_pieces (newnary.length,
-                                                newnary.opcode,
-                                                newnary.type,
-                                                newnary.op[0],
-                                                newnary.op[1],
-                                                newnary.op[2],
-                                                newnary.op[3],
+               nary = vn_nary_op_insert_pieces (newnary->length,
+                                                newnary->opcode,
+                                                newnary->type,
+                                                &newnary->op[0],
                                                 result, new_val_id);
                PRE_EXPR_NARY (expr) = nary;
                constant = fully_constant_expression (expr);
@@ -1529,7 +1513,6 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
              }
            add_to_value (new_val_id, expr);
          }
-       phi_trans_add (oldexpr, expr, pred);
        return expr;
       }
       break;
@@ -1541,8 +1524,8 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
        tree vuse = ref->vuse;
        tree newvuse = vuse;
        VEC (vn_reference_op_s, heap) *newoperands = NULL;
-       bool changed = false;
-       unsigned int i, j;
+       bool changed = false, same_valid = true;
+       unsigned int i, j, n;
        vn_reference_op_t operand;
        vn_reference_t newref;
 
@@ -1551,89 +1534,85 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
          {
            pre_expr opresult;
            pre_expr leader;
-           tree oldop0 = operand->op0;
-           tree oldop1 = operand->op1;
-           tree oldop2 = operand->op2;
-           tree op0 = oldop0;
-           tree op1 = oldop1;
-           tree op2 = oldop2;
+           tree op[3];
            tree type = operand->type;
            vn_reference_op_s newop = *operand;
-
-           if (op0 && TREE_CODE (op0) == SSA_NAME)
+           op[0] = operand->op0;
+           op[1] = operand->op1;
+           op[2] = operand->op2;
+           for (n = 0; n < 3; ++n)
              {
-               unsigned int op_val_id = VN_INFO (op0)->value_id;
-               leader = find_leader_in_sets (op_val_id, set1, set2);
-               opresult = phi_translate_1 (leader, set1, set2,
-                                           pred, phiblock, seen);
-               if (opresult && opresult != leader)
+               unsigned int op_val_id;
+               if (!op[n])
+                 continue;
+               if (TREE_CODE (op[n]) != SSA_NAME)
                  {
-                   tree name = get_representative_for (opresult);
-                   if (!name)
+                   /* We can't possibly insert these.  */
+                   if (n != 0
+                       && !is_gimple_min_invariant (op[n]))
                      break;
-                   op0 = name;
+                   continue;
                  }
-               else if (!opresult)
-                 break;
-             }
-           changed |= op0 != oldop0;
-
-           if (op1 && TREE_CODE (op1) == SSA_NAME)
-             {
-               unsigned int op_val_id = VN_INFO (op1)->value_id;
+               op_val_id = VN_INFO (op[n])->value_id;
                leader = find_leader_in_sets (op_val_id, set1, set2);
-               opresult = phi_translate_1 (leader, set1, set2,
-                                           pred, phiblock, seen);
-               if (opresult && opresult != leader)
+               if (!leader)
+                 break;
+               /* Make sure we do not recursively translate ourselves
+                  like for translating a[n_1] with the leader for
+                  n_1 being a[n_1].  */
+               if (get_expression_id (leader) != get_expression_id (expr))
                  {
-                   tree name = get_representative_for (opresult);
-                   if (!name)
+                   opresult = phi_translate (leader, set1, set2,
+                                             pred, phiblock);
+                   if (!opresult)
                      break;
-                   op1 = name;
+                   if (opresult != leader)
+                     {
+                       tree name = get_representative_for (opresult);
+                       if (!name)
+                         break;
+                       changed |= name != op[n];
+                       op[n] = name;
+                     }
                  }
-               else if (!opresult)
-                 break;
              }
-           /* We can't possibly insert these.  */
-           else if (op1 && !is_gimple_min_invariant (op1))
-             break;
-           changed |= op1 != oldop1;
-           if (op2 && TREE_CODE (op2) == SSA_NAME)
+           if (n != 3)
              {
-               unsigned int op_val_id = VN_INFO (op2)->value_id;
-               leader = find_leader_in_sets (op_val_id, set1, set2);
-               opresult = phi_translate_1 (leader, set1, set2,
-                                           pred, phiblock, seen);
-               if (opresult && opresult != leader)
-                 {
-                   tree name = get_representative_for (opresult);
-                   if (!name)
-                     break;
-                   op2 = name;
-                 }
-               else if (!opresult)
-                 break;
+               if (newoperands)
+                 VEC_free (vn_reference_op_s, heap, newoperands);
+               return NULL;
              }
-           /* We can't possibly insert these.  */
-           else if (op2 && !is_gimple_min_invariant (op2))
-             break;
-           changed |= op2 != oldop2;
-
            if (!newoperands)
              newoperands = VEC_copy (vn_reference_op_s, heap, operands);
            /* We may have changed from an SSA_NAME to a constant */
-           if (newop.opcode == SSA_NAME && TREE_CODE (op0) != SSA_NAME)
-             newop.opcode = TREE_CODE (op0);
+           if (newop.opcode == SSA_NAME && TREE_CODE (op[0]) != SSA_NAME)
+             newop.opcode = TREE_CODE (op[0]);
            newop.type = type;
-           newop.op0 = op0;
-           newop.op1 = op1;
-           newop.op2 = op2;
+           newop.op0 = op[0];
+           newop.op1 = op[1];
+           newop.op2 = op[2];
+           /* If it transforms a non-constant ARRAY_REF into a constant
+              one, adjust the constant offset.  */
+           if (newop.opcode == ARRAY_REF
+               && newop.off == -1
+               && TREE_CODE (op[0]) == INTEGER_CST
+               && TREE_CODE (op[1]) == INTEGER_CST
+               && TREE_CODE (op[2]) == INTEGER_CST)
+             {
+               double_int off = tree_to_double_int (op[0]);
+               off = double_int_add (off,
+                                     double_int_neg
+                                       (tree_to_double_int (op[1])));
+               off = double_int_mul (off, tree_to_double_int (op[2]));
+               if (double_int_fits_in_shwi_p (off))
+                 newop.off = off.low;
+             }
            VEC_replace (vn_reference_op_s, newoperands, j, &newop);
            /* If it transforms from an SSA_NAME to an address, fold with
               a preceding indirect reference.  */
-           if (j > 0 && op0 && TREE_CODE (op0) == ADDR_EXPR
+           if (j > 0 && op[0] && TREE_CODE (op[0]) == ADDR_EXPR
                && VEC_index (vn_reference_op_s,
-                             newoperands, j - 1)->opcode == INDIRECT_REF)
+                             newoperands, j - 1)->opcode == MEM_REF)
              vn_reference_fold_indirect (&newoperands, &j);
          }
        if (i != VEC_length (vn_reference_op_s, operands))
@@ -1647,27 +1626,41 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
          {
            newvuse = translate_vuse_through_block (newoperands,
                                                    ref->set, ref->type,
-                                                   vuse, phiblock, pred);
+                                                   vuse, phiblock, pred,
+                                                   &same_valid);
            if (newvuse == NULL_TREE)
              {
                VEC_free (vn_reference_op_s, heap, newoperands);
                return NULL;
              }
          }
-       changed |= newvuse != vuse;
 
-       if (changed)
+       if (changed || newvuse != vuse)
          {
            unsigned int new_val_id;
            pre_expr constant;
+           bool converted = false;
 
            tree result = vn_reference_lookup_pieces (newvuse, ref->set,
                                                      ref->type,
                                                      newoperands,
-                                                     &newref, true);
-           if (newref)
+                                                     &newref, VN_WALK);
+           if (result)
              VEC_free (vn_reference_op_s, heap, newoperands);
 
+           if (result
+               && !useless_type_conversion_p (ref->type, TREE_TYPE (result)))
+             {
+               result = fold_build1 (VIEW_CONVERT_EXPR, ref->type, result);
+               converted = true;
+             }
+           else if (!result && newref
+                    && !useless_type_conversion_p (ref->type, newref->type))
+             {
+               VEC_free (vn_reference_op_s, heap, newoperands);
+               return NULL;
+             }
+
            if (result && is_gimple_min_invariant (result))
              {
                gcc_assert (!newoperands);
@@ -1678,7 +1671,51 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
            expr->kind = REFERENCE;
            expr->id = 0;
 
-           if (newref)
+           if (converted)
+             {
+               vn_nary_op_t nary;
+               tree nresult;
+
+               gcc_assert (CONVERT_EXPR_P (result)
+                           || TREE_CODE (result) == VIEW_CONVERT_EXPR);
+
+               nresult = vn_nary_op_lookup_pieces (1, TREE_CODE (result),
+                                                   TREE_TYPE (result),
+                                                   &TREE_OPERAND (result, 0),
+                                                   &nary);
+               if (nresult && is_gimple_min_invariant (nresult))
+                 return get_or_alloc_expr_for_constant (nresult);
+
+               expr->kind = NARY;
+               if (nary)
+                 {
+                   PRE_EXPR_NARY (expr) = nary;
+                   constant = fully_constant_expression (expr);
+                   if (constant != expr)
+                     return constant;
+
+                   new_val_id = nary->value_id;
+                   get_or_alloc_expression_id (expr);
+                 }
+               else
+                 {
+                   new_val_id = get_next_value_id ();
+                   VEC_safe_grow_cleared (bitmap_set_t, heap,
+                                          value_expressions,
+                                          get_max_value_id() + 1);
+                   nary = vn_nary_op_insert_pieces (1, TREE_CODE (result),
+                                                    TREE_TYPE (result),
+                                                    &TREE_OPERAND (result, 0),
+                                                    NULL_TREE,
+                                                    new_val_id);
+                   PRE_EXPR_NARY (expr) = nary;
+                   constant = fully_constant_expression (expr);
+                   if (constant != expr)
+                     return constant;
+                   get_or_alloc_expression_id (expr);
+                 }
+             }
+           else if (newref)
              {
                PRE_EXPR_REFERENCE (expr) = newref;
                constant = fully_constant_expression (expr);
@@ -1690,9 +1727,15 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
              }
            else
              {
-               new_val_id = get_next_value_id ();
-               VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
-                                      get_max_value_id() + 1);
+               if (changed || !same_valid)
+                 {
+                   new_val_id = get_next_value_id ();
+                   VEC_safe_grow_cleared (bitmap_set_t, heap,
+                                          value_expressions,
+                                          get_max_value_id() + 1);
+                 }
+               else
+                 new_val_id = ref->value_id;
                newref = vn_reference_insert_pieces (newvuse, ref->set,
                                                     ref->type,
                                                     newoperands,
@@ -1707,7 +1750,6 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
            add_to_value (new_val_id, expr);
          }
        VEC_free (vn_reference_op_s, heap, newoperands);
-       phi_trans_add (oldexpr, expr, pred);
        return expr;
       }
       break;
@@ -1753,20 +1795,44 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
     }
 }
 
-/* Translate EXPR using phis in PHIBLOCK, so that it has the values of
-   the phis in PRED.
-   Return NULL if we can't find a leader for each part of the
-   translated expression.  */
+/* Wrapper around phi_translate_1 providing caching functionality.  */
 
 static pre_expr
 phi_translate (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
               basic_block pred, basic_block phiblock)
 {
-  bitmap_clear (seen_during_translate);
-  return phi_translate_1 (expr, set1, set2, pred, phiblock,
-                         seen_during_translate);
+  pre_expr phitrans;
+
+  if (!expr)
+    return NULL;
+
+  /* Constants contain no values that need translation.  */
+  if (expr->kind == CONSTANT)
+    return expr;
+
+  if (value_id_constant_p (get_expr_value_id (expr)))
+    return expr;
+
+  if (expr->kind != NAME)
+    {
+      phitrans = phi_trans_lookup (expr, pred);
+      if (phitrans)
+       return phitrans;
+    }
+
+  /* Translate.  */
+  phitrans = phi_translate_1 (expr, set1, set2, pred, phiblock);
+
+  /* Don't add empty translations to the cache.  Neither add
+     translations of NAMEs as those are cheap to translate.  */
+  if (phitrans
+      && expr->kind != NAME)
+    phi_trans_add (expr, phitrans, pred);
+
+  return phitrans;
 }
 
+
 /* For each expression in SET, translate the values through phi nodes
    in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
    expressions in DEST.  */
@@ -1779,23 +1845,27 @@ phi_translate_set (bitmap_set_t dest, bitmap_set_t set, basic_block pred,
   pre_expr expr;
   int i;
 
-  if (!phi_nodes (phiblock))
+  if (gimple_seq_empty_p (phi_nodes (phiblock)))
     {
       bitmap_set_copy (dest, set);
       return;
     }
 
   exprs = sorted_array_from_bitmap_set (set);
-  for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+  FOR_EACH_VEC_ELT (pre_expr, exprs, i, expr)
     {
       pre_expr translated;
       translated = phi_translate (expr, set, NULL, pred, phiblock);
+      if (!translated)
+       continue;
 
-      /* Don't add empty translations to the cache  */
-      if (translated)
-       phi_trans_add (expr, translated, pred);
-
-      if (translated != NULL)
+      /* We might end up with multiple expressions from SET being
+        translated to the same value.  In this case we do not want
+        to retain the NARY or REFERENCE expression but prefer a NAME
+        which would be the leader.  */
+      if (translated->kind == NAME)
+       bitmap_value_replace_in_set (dest, translated);
+      else
        bitmap_value_insert_into_set (dest, translated);
     }
   VEC_free (pre_expr, heap, exprs);
@@ -1839,8 +1909,8 @@ bitmap_find_leader (bitmap_set_t set, unsigned int val, gimple stmt)
       bitmap_iterator bi;
       bitmap_set_t exprset = VEC_index (bitmap_set_t, value_expressions, val);
 
-      EXECUTE_IF_AND_IN_BITMAP (exprset->expressions,
-                               set->expressions, 0, i, bi)
+      EXECUTE_IF_AND_IN_BITMAP (&exprset->expressions,
+                               &set->expressions, 0, i, bi)
        {
          pre_expr val = expression_for_id (i);
          /* At the point where stmt is not null, there should always
@@ -1850,7 +1920,10 @@ bitmap_find_leader (bitmap_set_t set, unsigned int val, gimple stmt)
              gimple def_stmt = SSA_NAME_DEF_STMT (PRE_EXPR_NAME (val));
              if (gimple_code (def_stmt) != GIMPLE_PHI
                  && gimple_bb (def_stmt) == gimple_bb (stmt)
-                 && gimple_uid (def_stmt) >= gimple_uid (stmt))
+                 /* PRE insertions are at the end of the basic-block
+                    and have UID 0.  */
+                 && (gimple_uid (def_stmt) == 0
+                     || gimple_uid (def_stmt) >= gimple_uid (stmt)))
                continue;
            }
          return val;
@@ -2027,6 +2100,13 @@ valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, pre_expr expr,
                  return false;
              }
          }
+       /* If the NARY may trap make sure the block does not contain
+          a possible exit point.
+          ???  This is overly conservative if we translate AVAIL_OUT
+          as the available expression might be after the exit point.  */
+       if (BB_MAY_NOTRETURN (block)
+           && vn_nary_may_trap (nary))
+         return false;
        return true;
       }
       break;
@@ -2036,7 +2116,7 @@ valid_in_sets (bitmap_set_t set1, bitmap_set_t set2, pre_expr expr,
        vn_reference_op_t vro;
        unsigned int i;
 
-       for (i = 0; VEC_iterate (vn_reference_op_s, ref->operands, i, vro); i++)
+       FOR_EACH_VEC_ELT (vn_reference_op_s, ref->operands, i, vro)
          {
            if (!vro_valid_in_sets (set1, set2, vro))
              return false;
@@ -2070,7 +2150,7 @@ dependent_clean (bitmap_set_t set1, bitmap_set_t set2, basic_block block)
   pre_expr expr;
   int i;
 
-  for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+  FOR_EACH_VEC_ELT (pre_expr, exprs, i, expr)
     {
       if (!valid_in_sets (set1, set2, expr, block))
        bitmap_remove_from_set (set1, expr);
@@ -2089,7 +2169,7 @@ clean (bitmap_set_t set, basic_block block)
   pre_expr expr;
   int i;
 
-  for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+  FOR_EACH_VEC_ELT (pre_expr, exprs, i, expr)
     {
       if (!valid_in_sets (set, NULL, expr, block))
        bitmap_remove_from_set (set, expr);
@@ -2218,14 +2298,14 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
          goto maybe_dump_sets;
        }
 
-      if (phi_nodes (first))
+      if (!gimple_seq_empty_p (phi_nodes (first)))
        phi_translate_set (ANTIC_OUT, ANTIC_IN (first), block, first);
       else
        bitmap_set_copy (ANTIC_OUT, ANTIC_IN (first));
 
-      for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
+      FOR_EACH_VEC_ELT (basic_block, worklist, i, bprime)
        {
-         if (phi_nodes (bprime))
+         if (!gimple_seq_empty_p (phi_nodes (bprime)))
            {
              bitmap_set_t tmp = bitmap_set_new ();
              phi_translate_set (tmp, ANTIC_IN (bprime), block, bprime);
@@ -2253,8 +2333,7 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
 
   clean (ANTIC_IN (block), block);
 
-  /* !old->expressions can happen when we deferred a block.  */
-  if (!old->expressions || !bitmap_set_equal (old, ANTIC_IN (block)))
+  if (!bitmap_set_equal (old, ANTIC_IN (block)))
     {
       changed = true;
       SET_BIT (changed_blocks, block->index);
@@ -2329,7 +2408,7 @@ compute_partial_antic_aux (basic_block block,
      before the translation starts.  */
   if (max_pa
       && single_succ_p (block)
-      && bitmap_count_bits (PA_IN (single_succ (block))->values) > max_pa)
+      && bitmap_count_bits (&PA_IN (single_succ (block))->values) > max_pa)
     goto maybe_dump_sets;
 
   old_PA_IN = PA_IN (block);
@@ -2367,7 +2446,7 @@ compute_partial_antic_aux (basic_block block,
        }
       if (VEC_length (basic_block, worklist) > 0)
        {
-         for (i = 0; VEC_iterate (basic_block, worklist, i, bprime); i++)
+         FOR_EACH_VEC_ELT (basic_block, worklist, i, bprime)
            {
              unsigned int i;
              bitmap_iterator bi;
@@ -2375,7 +2454,7 @@ compute_partial_antic_aux (basic_block block,
              FOR_EACH_EXPR_ID_IN_SET (ANTIC_IN (bprime), i, bi)
                bitmap_value_insert_into_set (PA_OUT,
                                              expression_for_id (i));
-             if (phi_nodes (bprime))
+             if (!gimple_seq_empty_p (phi_nodes (bprime)))
                {
                  bitmap_set_t pa_in = bitmap_set_new ();
                  phi_translate_set (pa_in, PA_IN (bprime), block, bprime);
@@ -2399,8 +2478,8 @@ compute_partial_antic_aux (basic_block block,
 
   /* For partial antic, we want to put back in the phi results, since
      we will properly avoid making them partially antic over backedges.  */
-  bitmap_ior_into (PA_IN (block)->values, PHI_GEN (block)->values);
-  bitmap_ior_into (PA_IN (block)->expressions, PHI_GEN (block)->expressions);
+  bitmap_ior_into (&PA_IN (block)->values, &PHI_GEN (block)->values);
+  bitmap_ior_into (&PA_IN (block)->expressions, &PHI_GEN (block)->expressions);
 
   /* PA_IN[block] = PA_IN[block] - ANTIC_IN[block] */
   bitmap_set_subtract_values (PA_IN (block), ANTIC_IN (block));
@@ -2464,6 +2543,7 @@ compute_antic (void)
 
       BB_VISITED (block) = 0;
       BB_DEFERRED (block) = 0;
+
       /* While we are here, give empty ANTIC_IN sets to each block.  */
       ANTIC_IN (block) = bitmap_set_new ();
       PA_IN (block) = bitmap_set_new ();
@@ -2480,9 +2560,13 @@ compute_antic (void)
     {
       if (dump_file && (dump_flags & TDF_DETAILS))
        fprintf (dump_file, "Starting iteration %d\n", num_iterations);
+      /* ???  We need to clear our PHI translation cache here as the
+         ANTIC sets shrink and we restrict valid translations to
+        those having operands with leaders in ANTIC.  Same below
+        for PA ANTIC computation.  */
       num_iterations++;
       changed = false;
-      for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
+      for (i = n_basic_blocks - NUM_FIXED_BLOCKS - 1; i >= 0; i--)
        {
          if (TEST_BIT (changed_blocks, postorder[i]))
            {
@@ -2492,10 +2576,8 @@ compute_antic (void)
                                                      block->index));
            }
        }
-#ifdef ENABLE_CHECKING
       /* Theoretically possible, but *highly* unlikely.  */
-      gcc_assert (num_iterations < 500);
-#endif
+      gcc_checking_assert (num_iterations < 500);
     }
 
   statistics_histogram_event (cfun, "compute_antic iterations",
@@ -2513,7 +2595,7 @@ compute_antic (void)
            fprintf (dump_file, "Starting iteration %d\n", num_iterations);
          num_iterations++;
          changed = false;
-         for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
+         for (i = n_basic_blocks - NUM_FIXED_BLOCKS - 1 ; i >= 0; i--)
            {
              if (TEST_BIT (changed_blocks, postorder[i]))
                {
@@ -2524,10 +2606,8 @@ compute_antic (void)
                                                            block->index));
                }
            }
-#ifdef ENABLE_CHECKING
          /* Theoretically possible, but *highly* unlikely.  */
-         gcc_assert (num_iterations < 500);
-#endif
+         gcc_checking_assert (num_iterations < 500);
        }
       statistics_histogram_event (cfun, "compute_partial_antic iterations",
                                  num_iterations);
@@ -2536,17 +2616,6 @@ compute_antic (void)
   sbitmap_free (changed_blocks);
 }
 
-/* Return true if we can value number the call in STMT.  This is true
-   if we have a pure or constant call.  */
-
-static bool
-can_value_number_call (gimple stmt)
-{
-  if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
-    return true;
-  return false;
-}
-
 /* Return true if OP is a tree which we can perform PRE on.
    This may not match the operations we can value number, but in
    a perfect world would.  */
@@ -2557,7 +2626,7 @@ can_PRE_operation (tree op)
   return UNARY_CLASS_P (op)
     || BINARY_CLASS_P (op)
     || COMPARISON_CLASS_P (op)
-    || TREE_CODE (op) == INDIRECT_REF
+    || TREE_CODE (op) == MEM_REF 
     || TREE_CODE (op) == COMPONENT_REF
     || TREE_CODE (op) == VIEW_CONVERT_EXPR
     || TREE_CODE (op) == CALL_EXPR
@@ -2568,8 +2637,7 @@ can_PRE_operation (tree op)
 /* Inserted expressions are placed onto this worklist, which is used
    for performing quick dead code elimination of insertions we made
    that didn't turn out to be necessary.   */
-static VEC(gimple,heap) *inserted_exprs;
-static bitmap inserted_phi_names;
+static bitmap inserted_exprs;
 
 /* Pool allocated fake store expressions are placed onto this
    worklist, which, after performing dead code elimination, is walked
@@ -2591,40 +2659,78 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
     {
     case CALL_EXPR:
       {
-       tree folded, sc = currop->op1;
+       tree folded, sc = NULL_TREE;
        unsigned int nargs = 0;
-       tree *args = XNEWVEC (tree, VEC_length (vn_reference_op_s,
-                                               ref->operands) - 1);
+       tree fn, *args;
+       if (TREE_CODE (currop->op0) == FUNCTION_DECL)
+         fn = currop->op0;
+       else
+         {
+           pre_expr op0 = get_or_alloc_expr_for (currop->op0);
+           fn = find_or_generate_expression (block, op0, stmts, domstmt);
+           if (!fn)
+             return NULL_TREE;
+         }
+       if (currop->op1)
+         {
+           pre_expr scexpr = get_or_alloc_expr_for (currop->op1);
+           sc = find_or_generate_expression (block, scexpr, stmts, domstmt);
+           if (!sc)
+             return NULL_TREE;
+         }
+       args = XNEWVEC (tree, VEC_length (vn_reference_op_s,
+                                         ref->operands) - 1);
        while (*operand < VEC_length (vn_reference_op_s, ref->operands))
          {
            args[nargs] = create_component_ref_by_pieces_1 (block, ref,
                                                            operand, stmts,
                                                            domstmt);
+           if (!args[nargs])
+             {
+               free (args);
+               return NULL_TREE;
+             }
            nargs++;
          }
        folded = build_call_array (currop->type,
-                                  TREE_CODE (currop->op0) == FUNCTION_DECL
-                                  ? build_fold_addr_expr (currop->op0)
-                                  : currop->op0,
+                                  (TREE_CODE (fn) == FUNCTION_DECL
+                                   ? build_fold_addr_expr (fn) : fn),
                                   nargs, args);
        free (args);
        if (sc)
+         CALL_EXPR_STATIC_CHAIN (folded) = sc;
+       return folded;
+      }
+      break;
+    case MEM_REF:
+      {
+       tree baseop = create_component_ref_by_pieces_1 (block, ref, operand,
+                                                       stmts, domstmt);
+       tree offset = currop->op0;
+       if (!baseop)
+         return NULL_TREE;
+       if (TREE_CODE (baseop) == ADDR_EXPR
+           && handled_component_p (TREE_OPERAND (baseop, 0)))
          {
-           pre_expr scexpr = get_or_alloc_expr_for (sc);
-           sc = find_or_generate_expression (block, scexpr, stmts, domstmt);
-           if (!sc)
-             return NULL_TREE;
-           CALL_EXPR_STATIC_CHAIN (folded) = sc;
+           HOST_WIDE_INT off;
+           tree base;
+           base = get_addr_base_and_unit_offset (TREE_OPERAND (baseop, 0),
+                                                 &off);
+           gcc_assert (base);
+           offset = int_const_binop (PLUS_EXPR, offset,
+                                     build_int_cst (TREE_TYPE (offset),
+                                                    off));
+           baseop = build_fold_addr_expr (base);
          }
-       return folded;
+       return fold_build2 (MEM_REF, currop->type, baseop, offset);
       }
       break;
     case TARGET_MEM_REF:
       {
+       pre_expr op0expr, op1expr;
+       tree genop0 = NULL_TREE, genop1 = NULL_TREE;
        vn_reference_op_t nextop = VEC_index (vn_reference_op_s, ref->operands,
-                                             *operand);
-       pre_expr op0expr;
-       tree genop0 = NULL_TREE;
+                                             ++*operand);
        tree baseop = create_component_ref_by_pieces_1 (block, ref, operand,
                                                        stmts, domstmt);
        if (!baseop)
@@ -2637,16 +2743,16 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
            if (!genop0)
              return NULL_TREE;
          }
-       if (DECL_P (baseop))
-         return build6 (TARGET_MEM_REF, currop->type,
-                        baseop, NULL_TREE,
-                        genop0, currop->op1, currop->op2,
-                        unshare_expr (nextop->op1));
-       else
-         return build6 (TARGET_MEM_REF, currop->type,
-                        NULL_TREE, baseop,
-                        genop0, currop->op1, currop->op2,
-                        unshare_expr (nextop->op1));
+       if (nextop->op0)
+         {
+           op1expr = get_or_alloc_expr_for (nextop->op0);
+           genop1 = find_or_generate_expression (block, op1expr,
+                                                 stmts, domstmt);
+           if (!genop1)
+             return NULL_TREE;
+         }
+       return build5 (TARGET_MEM_REF, currop->type,
+                      baseop, currop->op2, genop0, currop->op1, genop1);
       }
       break;
     case ADDR_EXPR:
@@ -2671,26 +2777,21 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
        return folded;
       }
       break;
-    case ALIGN_INDIRECT_REF:
-    case MISALIGNED_INDIRECT_REF:
-    case INDIRECT_REF:
+    case WITH_SIZE_EXPR:
       {
-       tree folded;
-       tree genop1 = create_component_ref_by_pieces_1 (block, ref,
-                                                       operand,
+       tree genop0 = create_component_ref_by_pieces_1 (block, ref, operand,
                                                        stmts, domstmt);
+       pre_expr op1expr = get_or_alloc_expr_for (currop->op0);
+       tree genop1;
+
+       if (!genop0)
+         return NULL_TREE;
+
+       genop1 = find_or_generate_expression (block, op1expr, stmts, domstmt);
        if (!genop1)
          return NULL_TREE;
-       genop1 = fold_convert (build_pointer_type (currop->type),
-                              genop1);
 
-       if (currop->opcode == MISALIGNED_INDIRECT_REF)
-         folded = fold_build2 (currop->opcode, currop->type,
-                               genop1, currop->op1);
-       else
-         folded = fold_build1 (currop->opcode, currop->type,
-                               genop1);
-       return folded;
+       return fold_build2 (currop->opcode, currop->type, genop0, genop1);
       }
       break;
     case BIT_FIELD_REF:
@@ -2739,22 +2840,40 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
          return NULL_TREE;
        if (genop2)
          {
-           op2expr = get_or_alloc_expr_for (genop2);
-           genop2 = find_or_generate_expression (block, op2expr, stmts,
-                                                 domstmt);
-           if (!genop2)
-             return NULL_TREE;
+           tree domain_type = TYPE_DOMAIN (TREE_TYPE (genop0));
+           /* Drop zero minimum index if redundant.  */
+           if (integer_zerop (genop2)
+               && (!domain_type
+                   || integer_zerop (TYPE_MIN_VALUE (domain_type))))
+             genop2 = NULL_TREE;
+           else
+             {
+               op2expr = get_or_alloc_expr_for (genop2);
+               genop2 = find_or_generate_expression (block, op2expr, stmts,
+                                                     domstmt);
+               if (!genop2)
+                 return NULL_TREE;
+             }
          }
        if (genop3)
          {
            tree elmt_type = TREE_TYPE (TREE_TYPE (genop0));
-           genop3 = size_binop (EXACT_DIV_EXPR, genop3,
-                                size_int (TYPE_ALIGN_UNIT (elmt_type)));
-           op3expr = get_or_alloc_expr_for (genop3);
-           genop3 = find_or_generate_expression (block, op3expr, stmts,
-                                                 domstmt);
-           if (!genop3)
-             return NULL_TREE;
+           /* We can't always put a size in units of the element alignment
+              here as the element alignment may be not visible.  See
+              PR43783.  Simply drop the element size for constant
+              sizes.  */
+           if (tree_int_cst_equal (genop3, TYPE_SIZE_UNIT (elmt_type)))
+             genop3 = NULL_TREE;
+           else
+             {
+               genop3 = size_binop (EXACT_DIV_EXPR, genop3,
+                                    size_int (TYPE_ALIGN_UNIT (elmt_type)));
+               op3expr = get_or_alloc_expr_for (genop3);
+               genop3 = find_or_generate_expression (block, op3expr, stmts,
+                                                     domstmt);
+               if (!genop3)
+                 return NULL_TREE;
+             }
          }
        return build4 (currop->opcode, currop->type, genop0, genop1,
                       genop2, genop3);
@@ -2810,7 +2929,7 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
 }
 
 /* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
-   COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
+   COMPONENT_REF or MEM_REF or ARRAY_REF portion, because we'd end up with
    trying to rename aggregates into ssa form directly, which is a no no.
 
    Thus, this routine doesn't create temporaries, it just builds a
@@ -2858,9 +2977,10 @@ find_or_generate_expression (basic_block block, pre_expr expr,
     }
 
   /* If it's still NULL, it must be a complex expression, so generate
-     it recursively.  Not so for FRE though.  */
+     it recursively.  Not so if inserting expressions for values generated
+     by SCCVN.  */
   if (genop == NULL
-      && !in_fre)
+      && !domstmt)
     {
       bitmap_set_t exprset;
       unsigned int lookfor = get_expr_value_id (expr);
@@ -2941,46 +3061,53 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
     case NARY:
       {
        vn_nary_op_t nary = PRE_EXPR_NARY (expr);
-       switch (nary->length)
+       tree *genop = XALLOCAVEC (tree, nary->length);
+       unsigned i;
+       for (i = 0; i < nary->length; ++i)
          {
-         case 2:
-           {
-             pre_expr op1 = get_or_alloc_expr_for (nary->op[0]);
-             pre_expr op2 = get_or_alloc_expr_for (nary->op[1]);
-             tree genop1 = find_or_generate_expression (block, op1,
-                                                        stmts, domstmt);
-             tree genop2 = find_or_generate_expression (block, op2,
-                                                        stmts, domstmt);
-             if (!genop1 || !genop2)
-               return NULL_TREE;
-             genop1 = fold_convert (TREE_TYPE (nary->op[0]),
-                                    genop1);
-             /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR.  It
-                may be a constant with the wrong type.  */
-             if (nary->opcode == POINTER_PLUS_EXPR)
-               genop2 = fold_convert (sizetype, genop2);
-             else
-               genop2 = fold_convert (TREE_TYPE (nary->op[1]), genop2);
-             
-             folded = fold_build2 (nary->opcode, nary->type,
-                                   genop1, genop2);
-           }
-           break;
-         case 1:
-           {
-             pre_expr op1 = get_or_alloc_expr_for (nary->op[0]);
-             tree genop1 = find_or_generate_expression (block, op1,
-                                                        stmts, domstmt);
-             if (!genop1)
-               return NULL_TREE;
-             genop1 = fold_convert (TREE_TYPE (nary->op[0]), genop1);
-
-             folded = fold_build1 (nary->opcode, nary->type,
-                                   genop1);
-           }
-           break;
-         default:
-           return NULL_TREE;
+           pre_expr op = get_or_alloc_expr_for (nary->op[i]);
+           genop[i] = find_or_generate_expression (block, op,
+                                                   stmts, domstmt);
+           if (!genop[i])
+             return NULL_TREE;
+           /* Ensure genop[] is properly typed for POINTER_PLUS_EXPR.  It
+              may have conversions stripped.  */
+           if (nary->opcode == POINTER_PLUS_EXPR)
+             {
+               if (i == 0)
+                 genop[i] = fold_convert (nary->type, genop[i]);
+               else if (i == 1)
+                 genop[i] = convert_to_ptrofftype (genop[i]);
+             }
+           else
+             genop[i] = fold_convert (TREE_TYPE (nary->op[i]), genop[i]);
+         }
+       if (nary->opcode == CONSTRUCTOR)
+         {
+           VEC(constructor_elt,gc) *elts = NULL;
+           for (i = 0; i < nary->length; ++i)
+             CONSTRUCTOR_APPEND_ELT (elts, NULL_TREE, genop[i]);
+           folded = build_constructor (nary->type, elts);
+         }
+       else
+         {
+           switch (nary->length)
+             {
+             case 1:
+               folded = fold_build1 (nary->opcode, nary->type,
+                                     genop[0]);
+               break;
+             case 2:
+               folded = fold_build2 (nary->opcode, nary->type,
+                                     genop[0], genop[1]);
+               break;
+             case 3:
+               folded = fold_build3 (nary->opcode, nary->type,
+                                     genop[0], genop[1], genop[2]);
+               break;
+             default:
+               gcc_unreachable ();
+             }
          }
       }
       break;
@@ -3009,9 +3136,9 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
          tree forcedname = gimple_get_lhs (stmt);
          pre_expr nameexpr;
 
-         VEC_safe_push (gimple, heap, inserted_exprs, stmt);
          if (TREE_CODE (forcedname) == SSA_NAME)
            {
+             bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (forcedname));
              VN_INFO_GET (forcedname)->valnum = forcedname;
              VN_INFO (forcedname)->value_id = get_next_value_id ();
              nameexpr = get_or_alloc_expr_for_name (forcedname);
@@ -3028,29 +3155,27 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
   /* Build and insert the assignment of the end result to the temporary
      that we will return.  */
   if (!pretemp || exprtype != TREE_TYPE (pretemp))
-    {
-      pretemp = create_tmp_var (exprtype, "pretmp");
-      get_var_ann (pretemp);
-    }
+    pretemp = create_tmp_reg (exprtype, "pretmp");
 
   temp = pretemp;
   add_referenced_var (temp);
 
-  if (TREE_CODE (exprtype) == COMPLEX_TYPE
-      || TREE_CODE (exprtype) == VECTOR_TYPE)
-    DECL_GIMPLE_REG_P (temp) = 1;
-
   newstmt = gimple_build_assign (temp, folded);
   name = make_ssa_name (temp, newstmt);
   gimple_assign_set_lhs (newstmt, name);
   gimple_set_plf (newstmt, NECESSARY, false);
 
   gimple_seq_add_stmt (stmts, newstmt);
-  VEC_safe_push (gimple, heap, inserted_exprs, newstmt);
+  bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (name));
 
   /* All the symbols in NEWEXPR should be put into SSA form.  */
   mark_symbols_for_renaming (newstmt);
 
+  /* Fold the last statement.  */
+  gsi = gsi_last (*stmts);
+  if (fold_stmt_inplace (&gsi))
+    update_stmt (gsi_stmt (gsi));
+
   /* Add a value number to the temporary.
      The value may already exist in either NEW_SETS, or AVAIL_OUT, because
      we are creating the expression by pieces, and this particular piece of
@@ -3061,7 +3186,7 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
   VN_INFO (name)->value_id = value_id;
   nameexpr = get_or_alloc_expr_for_name (name);
   add_to_value (value_id, nameexpr);
-  if (!in_fre)
+  if (NEW_SETS (block))
     bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
   bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr);
 
@@ -3098,7 +3223,7 @@ inhibit_phi_insertion (basic_block bb, pre_expr expr)
      memory reference is a simple induction variable.  In other
      cases the vectorizer won't do anything anyway (either it's
      loop invariant or a complicated expression).  */
-  for (i = 0; VEC_iterate (vn_reference_op_s, ops, i, op); ++i)
+  FOR_EACH_VEC_ELT (vn_reference_op_s, ops, i, op)
     {
       switch (op->opcode)
        {
@@ -3182,16 +3307,6 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
        }
     }
 
-  /* Make sure we are not inserting trapping expressions.  */
-  FOR_EACH_EDGE (pred, ei, block->preds)
-    {
-      bprime = pred->src;
-      eprime = avail[bprime->index];
-      if (eprime->kind == NARY
-         && vn_nary_may_trap (PRE_EXPR_NARY (eprime)))
-       return false;
-    }
-
   /* Make the necessary insertions.  */
   FOR_EACH_EDGE (pred, ei, block->preds)
     {
@@ -3220,7 +3335,7 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
          if (!useless_type_conversion_p (type, TREE_TYPE (constant)))
            {
              tree builtexpr = fold_convert (type, constant);
-             if (!is_gimple_min_invariant (builtexpr)) 
+             if (!is_gimple_min_invariant (builtexpr))
                {
                  tree forcedexpr = force_gimple_operand (builtexpr,
                                                          &stmts, true,
@@ -3239,7 +3354,10 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
                          for (; !gsi_end_p (gsi); gsi_next (&gsi))
                            {
                              gimple stmt = gsi_stmt (gsi);
-                             VEC_safe_push (gimple, heap, inserted_exprs, stmt);
+                             tree lhs = gimple_get_lhs (stmt);
+                             if (TREE_CODE (lhs) == SSA_NAME)
+                               bitmap_set_bit (inserted_exprs,
+                                               SSA_NAME_VERSION (lhs));
                              gimple_set_plf (stmt, NECESSARY, false);
                            }
                          gsi_insert_seq_on_edge (pred, stmts);
@@ -3247,6 +3365,8 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
                      avail[bprime->index] = get_or_alloc_expr_for_name (forcedexpr);
                    }
                }
+             else
+               avail[bprime->index] = get_or_alloc_expr_for_constant (builtexpr);
            }
        }
       else if (eprime->kind == NAME)
@@ -3278,7 +3398,9 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
                  for (; !gsi_end_p (gsi); gsi_next (&gsi))
                    {
                      gimple stmt = gsi_stmt (gsi);
-                     VEC_safe_push (gimple, heap, inserted_exprs, stmt);
+                     tree lhs = gimple_get_lhs (stmt);
+                     if (TREE_CODE (lhs) == SSA_NAME)
+                       bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (lhs));
                      gimple_set_plf (stmt, NECESSARY, false);
                    }
                  gsi_insert_seq_on_edge (pred, stmts);
@@ -3298,10 +3420,7 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
 
   /* Now build a phi for the new variable.  */
   if (!prephitemp || TREE_TYPE (prephitemp) != type)
-    {
-      prephitemp = create_tmp_var (type, "prephitmp");
-      get_var_ann (prephitemp);
-    }
+    prephitemp = create_tmp_var (type, "prephitmp");
 
   temp = prephitemp;
   add_referenced_var (temp);
@@ -3314,9 +3433,7 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
   gimple_set_plf (phi, NECESSARY, false);
   VN_INFO_GET (gimple_phi_result (phi))->valnum = gimple_phi_result (phi);
   VN_INFO (gimple_phi_result (phi))->value_id = val;
-  VEC_safe_push (gimple, heap, inserted_exprs, phi);
-  bitmap_set_bit (inserted_phi_names,
-                 SSA_NAME_VERSION (gimple_phi_result (phi)));
+  bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (gimple_phi_result (phi)));
   FOR_EACH_EDGE (pred, ei, block->preds)
     {
       pre_expr ae = avail[pred->src->index];
@@ -3390,9 +3507,10 @@ do_regular_insertion (basic_block block, basic_block dom)
   pre_expr expr;
   int i;
 
-  for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+  FOR_EACH_VEC_ELT (pre_expr, exprs, i, expr)
     {
-      if (expr->kind != NAME)
+      if (expr->kind == NARY
+         || expr->kind == REFERENCE)
        {
          pre_expr *avail;
          unsigned int val;
@@ -3405,6 +3523,7 @@ do_regular_insertion (basic_block block, basic_block dom)
          pre_expr eprime = NULL;
          edge_iterator ei;
          pre_expr edoubleprime = NULL;
+         bool do_insertion = false;
 
          val = get_expr_value_id (expr);
          if (bitmap_set_contains_value (PHI_GEN (block), val))
@@ -3456,6 +3575,10 @@ do_regular_insertion (basic_block block, basic_block dom)
                {
                  avail[bprime->index] = edoubleprime;
                  by_some = true;
+                 /* We want to perform insertions to remove a redundancy on
+                    a path in the CFG we want to optimize for speed.  */
+                 if (optimize_edge_for_speed_p (pred))
+                   do_insertion = true;
                  if (first_s == NULL)
                    first_s = edoubleprime;
                  else if (!pre_expr_eq (first_s, edoubleprime))
@@ -3466,45 +3589,58 @@ do_regular_insertion (basic_block block, basic_block dom)
             already existing along every predecessor, and
             it's defined by some predecessor, it is
             partially redundant.  */
-         if (!cant_insert && !all_same && by_some && dbg_cnt (treepre_insert))
+         if (!cant_insert && !all_same && by_some)
            {
-             if (insert_into_preds_of_block (block, get_expression_id (expr),
-                                             avail))
+             if (!do_insertion)
+               {
+                 if (dump_file && (dump_flags & TDF_DETAILS))
+                   {
+                     fprintf (dump_file, "Skipping partial redundancy for "
+                              "expression ");
+                     print_pre_expr (dump_file, expr);
+                     fprintf (dump_file, " (%04d), no redundancy on to be "
+                              "optimized for speed edge\n", val);
+                   }
+               }
+             else if (dbg_cnt (treepre_insert)
+                      && insert_into_preds_of_block (block,
+                                                     get_expression_id (expr),
+                                                     avail))
                new_stuff = true;
            }
          /* If all edges produce the same value and that value is
             an invariant, then the PHI has the same value on all
             edges.  Note this.  */
-         else if (!cant_insert && all_same && eprime
-                  && (edoubleprime->kind == CONSTANT
-                      || edoubleprime->kind == NAME)
-                  && !value_id_constant_p (val))
+         else if (!cant_insert && all_same)
            {
-             unsigned int j;
-             bitmap_iterator bi;
-             bitmap_set_t exprset = VEC_index (bitmap_set_t,
-                                               value_expressions, val);
+             tree exprtype = get_expr_type (expr);
+             tree temp;
+             gimple assign;
+             pre_expr newe;
+             gimple_stmt_iterator gsi;
 
-             unsigned int new_val = get_expr_value_id (edoubleprime);
-             FOR_EACH_EXPR_ID_IN_SET (exprset, j, bi)
-               {
-                 pre_expr expr = expression_for_id (j);
+             gcc_assert (edoubleprime->kind == CONSTANT
+                         || edoubleprime->kind == NAME);
 
-                 if (expr->kind == NAME)
-                   {
-                     vn_ssa_aux_t info = VN_INFO (PRE_EXPR_NAME (expr));
-                     /* Just reset the value id and valnum so it is
-                        the same as the constant we have discovered.  */
-                     if (edoubleprime->kind == CONSTANT)
-                       {
-                         info->valnum = PRE_EXPR_CONSTANT (edoubleprime);
-                         pre_stats.constified++;
-                       }
-                     else
-                       info->valnum = VN_INFO (PRE_EXPR_NAME (edoubleprime))->valnum;
-                     info->value_id = new_val;
-                   }
+             if (!pretemp || TREE_TYPE (pretemp) != exprtype)
+               {
+                 pretemp = create_tmp_reg (exprtype, "pretmp");
+                 add_referenced_var (pretemp);
                }
+             temp = make_ssa_name (pretemp, NULL);
+             assign = gimple_build_assign (temp,
+                                           edoubleprime->kind == CONSTANT ? PRE_EXPR_CONSTANT (edoubleprime) : PRE_EXPR_NAME (edoubleprime));
+             gsi = gsi_after_labels (block);
+             gsi_insert_before (&gsi, assign, GSI_NEW_STMT);
+
+             gimple_set_plf (assign, NECESSARY, false);
+             VN_INFO_GET (temp)->value_id = val;
+             VN_INFO (temp)->valnum = temp;
+             bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (temp));
+             newe = get_or_alloc_expr_for_name (temp);
+             add_to_value (val, newe);
+             bitmap_value_replace_in_set (AVAIL_OUT (block), newe);
+             bitmap_insert_into_set (NEW_SETS (block), newe);
            }
          free (avail);
        }
@@ -3530,9 +3666,10 @@ do_partial_partial_insertion (basic_block block, basic_block dom)
   pre_expr expr;
   int i;
 
-  for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
+  FOR_EACH_VEC_ELT (pre_expr, exprs, i, expr)
     {
-      if (expr->kind != NAME)
+      if (expr->kind == NARY
+         || expr->kind == REFERENCE)
        {
          pre_expr *avail;
          unsigned int val;
@@ -3793,6 +3930,8 @@ compute_avail (void)
       for (gsi = gsi_start_phis (block); !gsi_end_p (gsi); gsi_next (&gsi))
        make_values_for_phi (gsi_stmt (gsi), block);
 
+      BB_MAY_NOTRETURN (block) = 0;
+
       /* Now compute value numbers and populate value sets with all
         the expressions computed in BLOCK.  */
       for (gsi = gsi_start_bb (block); !gsi_end_p (gsi); gsi_next (&gsi))
@@ -3803,6 +3942,22 @@ compute_avail (void)
          stmt = gsi_stmt (gsi);
          gimple_set_uid (stmt, stmt_uid++);
 
+         /* Cache whether the basic-block has any non-visible side-effect
+            or control flow.
+            If this isn't a call or it is the last stmt in the
+            basic-block then the CFG represents things correctly.  */
+         if (is_gimple_call (stmt) && !stmt_ends_bb_p (stmt))
+           {
+             /* Non-looping const functions always return normally.
+                Otherwise the call might not return or have side-effects
+                that forbids hoisting possibly trapping expressions
+                before it.  */
+             int flags = gimple_call_flags (stmt);
+             if (!(flags & ECF_CONST)
+                 || (flags & ECF_LOOPING_CONST_OR_PURE))
+               BB_MAY_NOTRETURN (block) = 1;
+           }
+
          FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
            {
              pre_expr e = get_or_alloc_expr_for_name (op);
@@ -3813,8 +3968,7 @@ compute_avail (void)
              bitmap_value_insert_into_set (AVAIL_OUT (block), e);
            }
 
-         if (gimple_has_volatile_ops (stmt)
-             || stmt_could_throw_p (stmt))
+         if (gimple_has_side_effects (stmt) || stmt_could_throw_p (stmt))
            continue;
 
          switch (gimple_code (stmt))
@@ -3832,13 +3986,14 @@ compute_avail (void)
                pre_expr result = NULL;
                VEC(vn_reference_op_s, heap) *ops = NULL;
 
-               if (!can_value_number_call (stmt))
+               /* We can value number only calls to real functions.  */
+               if (gimple_call_internal_p (stmt))
                  continue;
 
                copy_reference_ops_from_call (stmt, &ops);
                vn_reference_lookup_pieces (gimple_vuse (stmt), 0,
                                            gimple_expr_type (stmt),
-                                           ops, &ref, false);
+                                           ops, &ref, VN_NOWALK);
                VEC_free (vn_reference_op_s, heap, ops);
                if (!ref)
                  continue;
@@ -3881,9 +4036,8 @@ compute_avail (void)
                      vn_nary_op_lookup_pieces (gimple_num_ops (stmt) - 1,
                                                gimple_assign_rhs_code (stmt),
                                                gimple_expr_type (stmt),
-                                               gimple_assign_rhs1 (stmt),
-                                               gimple_assign_rhs2 (stmt),
-                                               NULL_TREE, NULL_TREE, &nary);
+                                               gimple_assign_rhs1_ptr (stmt),
+                                               &nary);
 
                      if (!nary)
                        continue;
@@ -3908,7 +4062,7 @@ compute_avail (void)
 
                      vn_reference_lookup (gimple_assign_rhs1 (stmt),
                                           gimple_vuse (stmt),
-                                          false, &ref);
+                                          VN_WALK, &ref);
                      if (!ref)
                        continue;
 
@@ -3999,6 +4153,7 @@ static unsigned int
 eliminate (void)
 {
   VEC (gimple, heap) *to_remove = NULL;
+  VEC (gimple, heap) *to_update = NULL;
   basic_block b;
   unsigned int todo = 0;
   gimple_stmt_iterator gsi;
@@ -4009,27 +4164,40 @@ eliminate (void)
     {
       for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
        {
+         tree lhs = NULL_TREE;
+         tree rhs = NULL_TREE;
+
          stmt = gsi_stmt (gsi);
 
+         if (gimple_has_lhs (stmt))
+           lhs = gimple_get_lhs (stmt);
+
+         if (gimple_assign_single_p (stmt))
+           rhs = gimple_assign_rhs1 (stmt);
+
          /* Lookup the RHS of the expression, see if we have an
             available computation for it.  If so, replace the RHS with
-            the available computation.  */
+            the available computation.
+
+            See PR43491.
+            We don't replace global register variable when it is a the RHS of
+            a single assign. We do replace local register variable since gcc
+            does not guarantee local variable will be allocated in register.  */
          if (gimple_has_lhs (stmt)
-             && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME
+             && TREE_CODE (lhs) == SSA_NAME
              && !gimple_assign_ssa_name_copy_p (stmt)
              && (!gimple_assign_single_p (stmt)
-                 || !is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+                 || (!is_gimple_min_invariant (rhs)
+                      && (gimple_assign_rhs_code (stmt) != VAR_DECL
+                          || !is_global_var (rhs)
+                          || !DECL_HARD_REGISTER (rhs))))
              && !gimple_has_volatile_ops  (stmt)
-             && !has_zero_uses (gimple_get_lhs (stmt)))
+             && !has_zero_uses (lhs))
            {
-             tree lhs = gimple_get_lhs (stmt);
-             tree rhs = NULL_TREE;
              tree sprime = NULL;
              pre_expr lhsexpr = get_or_alloc_expr_for_name (lhs);
              pre_expr sprimeexpr;
-
-             if (gimple_assign_single_p (stmt))
-               rhs = gimple_assign_rhs1 (stmt);
+             gimple orig_stmt = stmt;
 
              sprimeexpr = bitmap_find_leader (AVAIL_OUT (b),
                                               get_expr_value_id (lhsexpr),
@@ -4067,6 +4235,16 @@ eliminate (void)
                  propagate_tree_value_into_stmt (&gsi, sprime);
                  stmt = gsi_stmt (gsi);
                  update_stmt (stmt);
+
+                 /* If we removed EH side-effects from the statement, clean
+                    its EH information.  */
+                 if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
+                   {
+                     bitmap_set_bit (need_eh_cleanup,
+                                     gimple_bb (stmt)->index);
+                     if (dump_file && (dump_flags & TDF_DETAILS))
+                       fprintf (dump_file, "  Removed EH side-effects.\n");
+                   }
                  continue;
                }
 
@@ -4088,6 +4266,10 @@ eliminate (void)
                      || TREE_CODE (rhs) != SSA_NAME
                      || may_propagate_copy (rhs, sprime)))
                {
+                 bool can_make_abnormal_goto
+                   = is_gimple_call (stmt)
+                     && stmt_can_make_abnormal_goto (stmt);
+
                  gcc_assert (sprime != rhs);
 
                  if (dump_file && (dump_flags & TDF_DETAILS))
@@ -4116,14 +4298,24 @@ eliminate (void)
                  stmt = gsi_stmt (gsi);
                  update_stmt (stmt);
 
-                 /* If we removed EH side effects from the statement, clean
+                 /* If we removed EH side-effects from the statement, clean
                     its EH information.  */
-                 if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
+                 if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
                    {
                      bitmap_set_bit (need_eh_cleanup,
                                      gimple_bb (stmt)->index);
                      if (dump_file && (dump_flags & TDF_DETAILS))
-                       fprintf (dump_file, "  Removed EH side effects.\n");
+                       fprintf (dump_file, "  Removed EH side-effects.\n");
+                   }
+
+                 /* Likewise for AB side-effects.  */
+                 if (can_make_abnormal_goto
+                     && !stmt_can_make_abnormal_goto (stmt))
+                   {
+                     bitmap_set_bit (need_ab_cleanup,
+                                     gimple_bb (stmt)->index);
+                     if (dump_file && (dump_flags & TDF_DETAILS))
+                       fprintf (dump_file, "  Removed AB side-effects.\n");
                    }
                }
            }
@@ -4131,14 +4323,14 @@ eliminate (void)
             has the same value number as its rhs.  If so, the store is
             dead.  */
          else if (gimple_assign_single_p (stmt)
+                  && !gimple_has_volatile_ops (stmt)
                   && !is_gimple_reg (gimple_assign_lhs (stmt))
-                  && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
-                      || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+                  && (TREE_CODE (rhs) == SSA_NAME
+                      || is_gimple_min_invariant (rhs)))
            {
-             tree rhs = gimple_assign_rhs1 (stmt);
              tree val;
              val = vn_reference_lookup (gimple_assign_lhs (stmt),
-                                        gimple_vuse (stmt), true, NULL);
+                                        gimple_vuse (stmt), VN_WALK, NULL);
              if (TREE_CODE (rhs) == SSA_NAME)
                rhs = VN_INFO (rhs)->valnum;
              if (val
@@ -4180,13 +4372,27 @@ eliminate (void)
            }
          /* Visit indirect calls and turn them into direct calls if
             possible.  */
-         if (gimple_code (stmt) == GIMPLE_CALL
-             && TREE_CODE (gimple_call_fn (stmt)) == SSA_NAME)
+         if (is_gimple_call (stmt))
            {
-             tree fn = VN_INFO (gimple_call_fn (stmt))->valnum;
-             if (TREE_CODE (fn) == ADDR_EXPR
-                 && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL)
+             tree orig_fn = gimple_call_fn (stmt);
+             tree fn;
+             if (!orig_fn)
+               continue;
+             if (TREE_CODE (orig_fn) == SSA_NAME)
+               fn = VN_INFO (orig_fn)->valnum;
+             else if (TREE_CODE (orig_fn) == OBJ_TYPE_REF
+                      && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn)) == SSA_NAME)
+               fn = VN_INFO (OBJ_TYPE_REF_EXPR (orig_fn))->valnum;
+             else
+               continue;
+             if (gimple_call_addr_fndecl (fn) != NULL_TREE
+                 && useless_type_conversion_p (TREE_TYPE (orig_fn),
+                                               TREE_TYPE (fn)))
                {
+                 bool can_make_abnormal_goto
+                   = stmt_can_make_abnormal_goto (stmt);
+                 bool was_noreturn = gimple_call_noreturn_p (stmt);
+
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    {
                      fprintf (dump_file, "Replacing call target with ");
@@ -4196,13 +4402,31 @@ eliminate (void)
                    }
 
                  gimple_call_set_fn (stmt, fn);
-                 update_stmt (stmt);
+                 VEC_safe_push (gimple, heap, to_update, stmt);
+
+                 /* When changing a call into a noreturn call, cfg cleanup
+                    is needed to fix up the noreturn call.  */
+                 if (!was_noreturn && gimple_call_noreturn_p (stmt))
+                   todo |= TODO_cleanup_cfg;
+
+                 /* If we removed EH side-effects from the statement, clean
+                    its EH information.  */
                  if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
                    {
                      bitmap_set_bit (need_eh_cleanup,
                                      gimple_bb (stmt)->index);
                      if (dump_file && (dump_flags & TDF_DETAILS))
-                       fprintf (dump_file, "  Removed EH side effects.\n");
+                       fprintf (dump_file, "  Removed EH side-effects.\n");
+                   }
+
+                 /* Likewise for AB side-effects.  */
+                 if (can_make_abnormal_goto
+                     && !stmt_can_make_abnormal_goto (stmt))
+                   {
+                     bitmap_set_bit (need_ab_cleanup,
+                                     gimple_bb (stmt)->index);
+                     if (dump_file && (dump_flags & TDF_DETAILS))
+                       fprintf (dump_file, "  Removed AB side-effects.\n");
                    }
 
                  /* Changing an indirect call to a direct call may
@@ -4224,8 +4448,7 @@ eliminate (void)
             replacing the PHI with a single copy if possible.
             Do not touch inserted, single-argument or virtual PHIs.  */
          if (gimple_phi_num_args (phi) == 1
-             || !is_gimple_reg (res)
-             || bitmap_bit_p (inserted_phi_names, SSA_NAME_VERSION (res)))
+             || !is_gimple_reg (res))
            {
              gsi_next (&gsi);
              continue;
@@ -4243,7 +4466,14 @@ eliminate (void)
              else
                gcc_unreachable ();
            }
-         if (!sprimeexpr
+         if (!sprime && is_gimple_min_invariant (VN_INFO (res)->valnum))
+           {
+             sprime = VN_INFO (res)->valnum;
+             if (!useless_type_conversion_p (TREE_TYPE (res),
+                                             TREE_TYPE (sprime)))
+               sprime = fold_convert (TREE_TYPE (res), sprime);
+           }
+         if (!sprime
              || sprime == res)
            {
              gsi_next (&gsi);
@@ -4261,53 +4491,78 @@ eliminate (void)
 
          remove_phi_node (&gsi, false);
 
+         if (!bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res))
+             && TREE_CODE (sprime) == SSA_NAME)
+           gimple_set_plf (SSA_NAME_DEF_STMT (sprime), NECESSARY, true);
+
          if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
            sprime = fold_convert (TREE_TYPE (res), sprime);
          stmt = gimple_build_assign (res, sprime);
          SSA_NAME_DEF_STMT (res) = stmt;
-         if (TREE_CODE (sprime) == SSA_NAME)
-           gimple_set_plf (SSA_NAME_DEF_STMT (sprime),
-                           NECESSARY, true);
+         gimple_set_plf (stmt, NECESSARY, gimple_plf (phi, NECESSARY));
+
          gsi2 = gsi_after_labels (b);
          gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
          /* Queue the copy for eventual removal.  */
          VEC_safe_push (gimple, heap, to_remove, stmt);
-         pre_stats.eliminations++;
+         /* If we inserted this PHI node ourself, it's not an elimination.  */
+         if (bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
+           pre_stats.phis--;
+         else
+           pre_stats.eliminations++;
        }
     }
 
   /* We cannot remove stmts during BB walk, especially not release SSA
      names there as this confuses the VN machinery.  The stmts ending
      up in to_remove are either stores or simple copies.  */
-  for (i = 0; VEC_iterate (gimple, to_remove, i, stmt); ++i)
+  FOR_EACH_VEC_ELT (gimple, to_remove, i, stmt)
     {
       tree lhs = gimple_assign_lhs (stmt);
+      tree rhs = gimple_assign_rhs1 (stmt);
       use_operand_p use_p;
       gimple use_stmt;
 
       /* If there is a single use only, propagate the equivalency
         instead of keeping the copy.  */
       if (TREE_CODE (lhs) == SSA_NAME
+         && TREE_CODE (rhs) == SSA_NAME
          && single_imm_use (lhs, &use_p, &use_stmt)
-         && may_propagate_copy (USE_FROM_PTR (use_p),
-                                gimple_assign_rhs1 (stmt)))
+         && may_propagate_copy (USE_FROM_PTR (use_p), rhs))
        {
-         SET_USE (use_p, gimple_assign_rhs1 (stmt));
+         SET_USE (use_p, rhs);
          update_stmt (use_stmt);
+         if (bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (lhs))
+             && TREE_CODE (rhs) == SSA_NAME)
+           gimple_set_plf (SSA_NAME_DEF_STMT (rhs), NECESSARY, true);
        }
 
       /* If this is a store or a now unused copy, remove it.  */
       if (TREE_CODE (lhs) != SSA_NAME
          || has_zero_uses (lhs))
        {
+         basic_block bb = gimple_bb (stmt);
          gsi = gsi_for_stmt (stmt);
          unlink_stmt_vdef (stmt);
          gsi_remove (&gsi, true);
+         /* ???  gsi_remove doesn't tell us whether the stmt was
+            in EH tables and thus whether we need to purge EH edges.
+            Simply schedule the block for a cleanup.  */
+         bitmap_set_bit (need_eh_cleanup, bb->index);
+         if (TREE_CODE (lhs) == SSA_NAME)
+           bitmap_clear_bit (inserted_exprs, SSA_NAME_VERSION (lhs));
          release_defs (stmt);
        }
     }
   VEC_free (gimple, heap, to_remove);
 
+  /* We cannot update call statements with virtual operands during
+     SSA walk.  This might remove them which in turn makes our
+     VN lattice invalid.  */
+  FOR_EACH_VEC_ELT (gimple, to_update, i, stmt)
+    update_stmt (stmt);
+  VEC_free (gimple, heap, to_update);
+
   return todo;
 }
 
@@ -4348,19 +4603,23 @@ mark_operand_necessary (tree op)
 static void
 remove_dead_inserted_code (void)
 {
-  VEC(gimple,heap) *worklist = NULL;
-  int i;
+  bitmap worklist;
+  unsigned i;
+  bitmap_iterator bi;
   gimple t;
 
-  worklist = VEC_alloc (gimple, heap, VEC_length (gimple, inserted_exprs));
-  for (i = 0; VEC_iterate (gimple, inserted_exprs, i, t); i++)
+  worklist = BITMAP_ALLOC (NULL);
+  EXECUTE_IF_SET_IN_BITMAP (inserted_exprs, 0, i, bi)
     {
+      t = SSA_NAME_DEF_STMT (ssa_name (i));
       if (gimple_plf (t, NECESSARY))
-       VEC_quick_push (gimple, worklist, t);
+       bitmap_set_bit (worklist, i);
     }
-  while (VEC_length (gimple, worklist) > 0)
+  while (!bitmap_empty_p (worklist))
     {
-      t = VEC_pop (gimple, worklist);
+      i = bitmap_first_set_bit (worklist);
+      bitmap_clear_bit (worklist, i);
+      t = SSA_NAME_DEF_STMT (ssa_name (i));
 
       /* PHI nodes are somewhat special in that each PHI alternative has
         data and control dependencies.  All the statements feeding the
@@ -4369,7 +4628,6 @@ remove_dead_inserted_code (void)
        {
          unsigned k;
 
-         VEC_reserve (gimple, heap, worklist, gimple_phi_num_args (t));
          for (k = 0; k < gimple_phi_num_args (t); k++)
            {
              tree arg = PHI_ARG_DEF (t, k);
@@ -4377,7 +4635,7 @@ remove_dead_inserted_code (void)
                {
                  gimple n = mark_operand_necessary (arg);
                  if (n)
-                   VEC_quick_push (gimple, worklist, n);
+                   bitmap_set_bit (worklist, SSA_NAME_VERSION (arg));
                }
            }
        }
@@ -4398,13 +4656,14 @@ remove_dead_inserted_code (void)
            {
              gimple n = mark_operand_necessary (use);
              if (n)
-               VEC_safe_push (gimple, heap, worklist, n);
+               bitmap_set_bit (worklist, SSA_NAME_VERSION (use));
            }
        }
     }
 
-  for (i = 0; VEC_iterate (gimple, inserted_exprs, i, t); i++)
+  EXECUTE_IF_SET_IN_BITMAP (inserted_exprs, 0, i, bi)
     {
+      t = SSA_NAME_DEF_STMT (ssa_name (i));
       if (!gimple_plf (t, NECESSARY))
        {
          gimple_stmt_iterator gsi;
@@ -4419,13 +4678,88 @@ remove_dead_inserted_code (void)
          if (gimple_code (t) == GIMPLE_PHI)
            remove_phi_node (&gsi, true);
          else
-           gsi_remove (&gsi, true);
-         release_defs (t);
+           {
+             gsi_remove (&gsi, true);
+             release_defs (t);
+           }
        }
     }
-  VEC_free (gimple, heap, worklist);
+  BITMAP_FREE (worklist);
 }
 
+/* Compute a reverse post-order in *POST_ORDER.  If INCLUDE_ENTRY_EXIT is
+   true, then then ENTRY_BLOCK and EXIT_BLOCK are included.  Returns
+   the number of visited blocks.  */
+
+static int
+my_rev_post_order_compute (int *post_order, bool include_entry_exit)
+{
+  edge_iterator *stack;
+  int sp;
+  int post_order_num = 0;
+  sbitmap visited;
+
+  if (include_entry_exit)
+    post_order[post_order_num++] = EXIT_BLOCK;
+
+  /* Allocate stack for back-tracking up CFG.  */
+  stack = XNEWVEC (edge_iterator, n_basic_blocks + 1);
+  sp = 0;
+
+  /* Allocate bitmap to track nodes that have been visited.  */
+  visited = sbitmap_alloc (last_basic_block);
+
+  /* None of the nodes in the CFG have been visited yet.  */
+  sbitmap_zero (visited);
+
+  /* Push the last edge on to the stack.  */
+  stack[sp++] = ei_start (EXIT_BLOCK_PTR->preds);
+
+  while (sp)
+    {
+      edge_iterator ei;
+      basic_block src;
+      basic_block dest;
+
+      /* Look at the edge on the top of the stack.  */
+      ei = stack[sp - 1];
+      src = ei_edge (ei)->src;
+      dest = ei_edge (ei)->dest;
+
+      /* Check if the edge destination has been visited yet.  */
+      if (src != ENTRY_BLOCK_PTR && ! TEST_BIT (visited, src->index))
+        {
+          /* Mark that we have visited the destination.  */
+          SET_BIT (visited, src->index);
+
+          if (EDGE_COUNT (src->preds) > 0)
+            /* Since the DEST node has been visited for the first
+               time, check its successors.  */
+            stack[sp++] = ei_start (src->preds);
+          else
+            post_order[post_order_num++] = src->index;
+        }
+      else
+        {
+          if (ei_one_before_end_p (ei) && dest != EXIT_BLOCK_PTR)
+            post_order[post_order_num++] = dest->index;
+
+          if (!ei_one_before_end_p (ei))
+            ei_next (&stack[sp - 1]);
+          else
+            sp--;
+        }
+    }
+
+  if (include_entry_exit)
+    post_order[post_order_num++] = ENTRY_BLOCK;
+
+  free (stack);
+  sbitmap_free (visited);
+  return post_order_num;
+}
+
+
 /* Initialize data structures used by PRE.  */
 
 static void
@@ -4439,10 +4773,11 @@ init_pre (bool do_fre)
   value_expressions = VEC_alloc (bitmap_set_t, heap, get_max_value_id () + 1);
   VEC_safe_grow_cleared (bitmap_set_t, heap, value_expressions,
                         get_max_value_id() + 1);
+  name_to_id = NULL;
 
   in_fre = do_fre;
 
-  inserted_exprs = NULL;
+  inserted_exprs = BITMAP_ALLOC (NULL);
   need_creation = NULL;
   pretemp = NULL_TREE;
   storetemp = NULL_TREE;
@@ -4453,22 +4788,19 @@ init_pre (bool do_fre)
 
 
   postorder = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
-  post_order_compute (postorder, false, false);
+  my_rev_post_order_compute (postorder, false);
 
-  FOR_ALL_BB (bb)
-    bb->aux = XCNEWVEC (struct bb_bitmap_sets, 1);
+  alloc_aux_for_blocks (sizeof (struct bb_bitmap_sets));
 
   calculate_dominance_info (CDI_POST_DOMINATORS);
   calculate_dominance_info (CDI_DOMINATORS);
 
   bitmap_obstack_initialize (&grand_bitmap_obstack);
-  inserted_phi_names = BITMAP_ALLOC (&grand_bitmap_obstack);
   phi_translate_table = htab_create (5110, expr_pred_trans_hash,
                                     expr_pred_trans_eq, free);
   expression_to_id = htab_create (num_ssa_names * 3,
                                  pre_expr_hash,
                                  pre_expr_eq, NULL);
-  seen_during_translate = BITMAP_ALLOC (&grand_bitmap_obstack);
   bitmap_set_pool = create_alloc_pool ("Bitmap sets",
                                       sizeof (struct bitmap_set), 30);
   pre_expr_pool = create_alloc_pool ("pre_expr nodes",
@@ -4482,75 +4814,78 @@ init_pre (bool do_fre)
     }
 
   need_eh_cleanup = BITMAP_ALLOC (NULL);
+  need_ab_cleanup = BITMAP_ALLOC (NULL);
 }
 
 
 /* Deallocate data structures used by PRE.  */
 
-static void
+static unsigned 
 fini_pre (bool do_fre)
 {
-  basic_block bb;
+  bool do_eh_cleanup = !bitmap_empty_p (need_eh_cleanup);
+  bool do_ab_cleanup = !bitmap_empty_p (need_ab_cleanup);
+  unsigned todo = 0;
 
   free (postorder);
   VEC_free (bitmap_set_t, heap, value_expressions);
-  VEC_free (gimple, heap, inserted_exprs);
+  BITMAP_FREE (inserted_exprs);
   VEC_free (gimple, heap, need_creation);
   bitmap_obstack_release (&grand_bitmap_obstack);
   free_alloc_pool (bitmap_set_pool);
   free_alloc_pool (pre_expr_pool);
   htab_delete (phi_translate_table);
   htab_delete (expression_to_id);
+  VEC_free (unsigned, heap, name_to_id);
 
-  FOR_ALL_BB (bb)
-    {
-      free (bb->aux);
-      bb->aux = NULL;
-    }
+  free_aux_for_blocks ();
 
   free_dominance_info (CDI_POST_DOMINATORS);
 
-  if (!bitmap_empty_p (need_eh_cleanup))
-    {
-      gimple_purge_all_dead_eh_edges (need_eh_cleanup);
-      cleanup_tree_cfg ();
-    }
+  if (do_eh_cleanup)
+    gimple_purge_all_dead_eh_edges (need_eh_cleanup);
+
+  if (do_ab_cleanup)
+    gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup);
 
   BITMAP_FREE (need_eh_cleanup);
+  BITMAP_FREE (need_ab_cleanup);
+
+  if (do_eh_cleanup || do_ab_cleanup)
+    todo = TODO_cleanup_cfg;
 
   if (!do_fre)
     loop_optimizer_finalize ();
+
+  return todo;
 }
 
 /* Main entry point to the SSA-PRE pass.  DO_FRE is true if the caller
    only wants to do full redundancy elimination.  */
 
 static unsigned int
-execute_pre (bool do_fre ATTRIBUTE_UNUSED)
+execute_pre (bool do_fre)
 {
   unsigned int todo = 0;
 
-  do_partial_partial = optimize > 2;
+  do_partial_partial = optimize > 2 && optimize_function_for_speed_p (cfun);
 
   /* This has to happen before SCCVN runs because
      loop_optimizer_init may create new phis, etc.  */
   if (!do_fre)
     loop_optimizer_init (LOOPS_NORMAL);
 
-  if (!run_scc_vn (do_fre))
+  if (!run_scc_vn (do_fre ? VN_WALKREWRITE : VN_WALK))
     {
       if (!do_fre)
-       {
-         remove_dead_inserted_code ();
-         loop_optimizer_finalize ();
-       }
-      
+       loop_optimizer_finalize ();
+
       return 0;
     }
+
   init_pre (do_fre);
   scev_initialize ();
 
-
   /* Collect and value number expressions computed in each basic block.  */
   compute_avail ();
 
@@ -4578,6 +4913,12 @@ execute_pre (bool do_fre ATTRIBUTE_UNUSED)
       insert ();
     }
 
+  /* Make sure to remove fake edges before committing our inserts.
+     This makes sure we don't end up with extra critical edges that
+     we would need to split.  */
+  remove_fake_exit_edges ();
+  gsi_commit_edge_inserts ();
+
   /* Remove all the redundant expressions.  */
   todo |= eliminate ();
 
@@ -4585,21 +4926,34 @@ execute_pre (bool do_fre ATTRIBUTE_UNUSED)
   statistics_counter_event (cfun, "PA inserted", pre_stats.pa_insert);
   statistics_counter_event (cfun, "New PHIs", pre_stats.phis);
   statistics_counter_event (cfun, "Eliminated", pre_stats.eliminations);
-  statistics_counter_event (cfun, "Constified", pre_stats.constified);
-
-  /* Make sure to remove fake edges before committing our inserts.
-     This makes sure we don't end up with extra critical edges that
-     we would need to split.  */
-  remove_fake_exit_edges ();
-  gsi_commit_edge_inserts ();
 
   clear_expression_ids ();
-  free_scc_vn ();
   if (!do_fre)
-    remove_dead_inserted_code ();
+    {
+      remove_dead_inserted_code ();
+      todo |= TODO_verify_flow;
+    }
 
   scev_finalize ();
-  fini_pre (do_fre);
+  todo |= fini_pre (do_fre);
+
+  if (!do_fre)
+    /* TODO: tail_merge_optimize may merge all predecessors of a block, in which
+       case we can merge the block with the remaining predecessor of the block.
+       It should either:
+       - call merge_blocks after each tail merge iteration
+       - call merge_blocks after all tail merge iterations
+       - mark TODO_cleanup_cfg when necessary
+       - share the cfg cleanup with fini_pre.  */
+    todo |= tail_merge_optimize (todo);
+  free_scc_vn ();
+
+  /* Tail merging invalidates the virtual SSA web, together with
+     cfg-cleanup opportunities exposed by PRE this will wreck the
+     SSA updating machinery.  So make sure to run update-ssa
+     manually, before eventually scheduling cfg-cleanup as part of
+     the todo.  */
+  update_ssa (TODO_update_ssa_only_virtuals);
 
   return todo;
 }
@@ -4615,8 +4969,7 @@ do_pre (void)
 static bool
 gate_pre (void)
 {
-  /* PRE tends to generate bigger code.  */
-  return flag_tree_pre != 0 && optimize_function_for_speed_p (cfun);
+  return flag_tree_pre != 0;
 }
 
 struct gimple_opt_pass pass_pre =
@@ -4635,8 +4988,7 @@ struct gimple_opt_pass pass_pre =
   0,                                   /* properties_provided */
   0,                                   /* properties_destroyed */
   TODO_rebuild_alias,                  /* todo_flags_start */
-  TODO_update_ssa_only_virtuals | TODO_dump_func | TODO_ggc_collect
-  | TODO_verify_ssa /* todo_flags_finish */
+  TODO_ggc_collect | TODO_verify_ssa   /* todo_flags_finish */
  }
 };
 
@@ -4670,6 +5022,6 @@ struct gimple_opt_pass pass_fre =
   0,                                   /* properties_provided */
   0,                                   /* properties_destroyed */
   0,                                   /* todo_flags_start */
-  TODO_dump_func | TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */
+  TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */
  }
 };