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[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-pre.c
index 41d0542..727614a 100644 (file)
@@ -448,10 +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;
@@ -484,10 +480,12 @@ 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;
 
+/* 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.  */
 
@@ -578,8 +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;
 }
 
@@ -861,6 +858,8 @@ bitmap_set_replace_value (bitmap_set_t set, unsigned int lookfor,
          return;
        }
     }
+
+  gcc_unreachable ();
 }
 
 /* Return true if two bitmap sets are equal.  */
@@ -893,9 +892,7 @@ bitmap_value_insert_into_set (bitmap_set_t set, pre_expr expr)
 {
   unsigned int val = get_expr_value_id (expr);
 
-#ifdef ENABLE_CHECKING
-  gcc_assert (expr->id == get_or_alloc_expression_id (expr));
-#endif
+  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))
@@ -1151,14 +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:
            {
@@ -1200,7 +1189,6 @@ fully_constant_expression (pre_expr e)
              return e;
            /* Fallthrough.  */
          case tcc_unary:
-do_unary:
            {
              /* We have to go from trees to pre exprs to value ids to
                 constants.  */
@@ -1293,7 +1281,7 @@ translate_vuse_through_block (VEC (vn_reference_op_s, heap) *operands,
          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);
+         vuse = get_continuation_for_phi (phi, &ref, &visited, false);
          if (visited)
            BITMAP_FREE (visited);
        }
@@ -1409,7 +1397,7 @@ get_representative_for (const pre_expr e)
   if (!pretemp || exprtype != TREE_TYPE (pretemp))
     {
       pretemp = create_tmp_reg (exprtype, "pretmp");
-      get_var_ann (pretemp);
+      add_referenced_var (pretemp);
     }
 
   name = make_ssa_name (pretemp, gimple_build_nop ());
@@ -1453,20 +1441,18 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
        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
              {
                 pre_expr leader, result;
-               unsigned int op_val_id = VN_INFO (newnary.op[i])->value_id;
+               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)
@@ -1474,12 +1460,12 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
                    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)
@@ -1487,13 +1473,10 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
            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);
            if (result && is_gimple_min_invariant (result))
              return get_or_alloc_expr_for_constant (result);
@@ -1517,13 +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);
@@ -1545,7 +1525,7 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
        tree newvuse = vuse;
        VEC (vn_reference_op_s, heap) *newoperands = NULL;
        bool changed = false, same_valid = true;
-       unsigned int i, j;
+       unsigned int i, j, n;
        vn_reference_op_t operand;
        vn_reference_t newref;
 
@@ -1554,100 +1534,83 @@ 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 (leader, set1, set2, pred, phiblock);
-               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 (leader, set1, set2, pred, phiblock);
-               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 (leader, set1, set2, pred, phiblock);
-               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 (op0) == INTEGER_CST
-               && TREE_CODE (op1) == INTEGER_CST
-               && TREE_CODE (op2) == INTEGER_CST)
+               && 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 (op0);
+               double_int off = tree_to_double_int (op[0]);
                off = double_int_add (off,
                                      double_int_neg
-                                       (tree_to_double_int (op1)));
-               off = double_int_mul (off, tree_to_double_int (op2));
+                                       (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 == MEM_REF)
              vn_reference_fold_indirect (&newoperands, &j);
@@ -1681,7 +1644,7 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
            tree result = vn_reference_lookup_pieces (newvuse, ref->set,
                                                      ref->type,
                                                      newoperands,
-                                                     &newref, true);
+                                                     &newref, VN_WALK);
            if (result)
              VEC_free (vn_reference_op_s, heap, newoperands);
 
@@ -1691,6 +1654,12 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
                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))
              {
@@ -1712,9 +1681,7 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
 
                nresult = vn_nary_op_lookup_pieces (1, TREE_CODE (result),
                                                    TREE_TYPE (result),
-                                                   TREE_OPERAND (result, 0),
-                                                   NULL_TREE, NULL_TREE,
-                                                   NULL_TREE,
+                                                   &TREE_OPERAND (result, 0),
                                                    &nary);
                if (nresult && is_gimple_min_invariant (nresult))
                  return get_or_alloc_expr_for_constant (nresult);
@@ -1738,9 +1705,8 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2,
                                           get_max_value_id() + 1);
                    nary = vn_nary_op_insert_pieces (1, TREE_CODE (result),
                                                     TREE_TYPE (result),
-                                                    TREE_OPERAND (result, 0),
-                                                    NULL_TREE, NULL_TREE,
-                                                    NULL_TREE, NULL_TREE,
+                                                    &TREE_OPERAND (result, 0),
+                                                    NULL_TREE,
                                                     new_val_id);
                    PRE_EXPR_NARY (expr) = nary;
                    constant = fully_constant_expression (expr);
@@ -2594,6 +2560,10 @@ 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 = n_basic_blocks - NUM_FIXED_BLOCKS - 1; i >= 0; i--)
@@ -2606,10 +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",
@@ -2638,10 +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);
@@ -2650,17 +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.  */
@@ -2764,7 +2719,7 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
            gcc_assert (base);
            offset = int_const_binop (PLUS_EXPR, offset,
                                      build_int_cst (TREE_TYPE (offset),
-                                                    off), 0);
+                                                    off));
            baseop = build_fold_addr_expr (base);
          }
        return fold_build2 (MEM_REF, currop->type, baseop, offset);
@@ -2822,6 +2777,23 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
        return folded;
       }
       break;
+    case WITH_SIZE_EXPR:
+      {
+       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;
+
+       return fold_build2 (currop->opcode, currop->type, genop0, genop1);
+      }
+      break;
     case BIT_FIELD_REF:
       {
        tree folded;
@@ -2868,8 +2840,11 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
          return NULL_TREE;
        if (genop2)
          {
-           /* Drop zero minimum index.  */
-           if (tree_int_cst_equal (genop2, integer_zero_node))
+           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
              {
@@ -3086,50 +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;
-             /* Ensure op2 is a sizetype for POINTER_PLUS_EXPR.  It
-                may be a constant with the wrong type.  */
-             if (nary->opcode == POINTER_PLUS_EXPR)
-               {
-                 genop1 = fold_convert (nary->type, genop1);
-                 genop2 = fold_convert (sizetype, genop2);
-               }
-             else
-               {
-                 genop1 = fold_convert (TREE_TYPE (nary->op[0]), genop1);
-                 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;
@@ -3177,10 +3155,7 @@ 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_reg (exprtype, "pretmp");
-      get_var_ann (pretemp);
-    }
+    pretemp = create_tmp_reg (exprtype, "pretmp");
 
   temp = pretemp;
   add_referenced_var (temp);
@@ -3196,6 +3171,11 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
   /* 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
@@ -3440,10 +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);
@@ -3532,7 +3509,8 @@ do_regular_insertion (basic_block block, basic_block dom)
 
   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;
@@ -3611,46 +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 && do_insertion
-             && 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);
        }
@@ -3678,7 +3668,8 @@ do_partial_partial_insertion (basic_block block, basic_block dom)
 
   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;
@@ -3955,8 +3946,7 @@ compute_avail (void)
             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))
+         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
@@ -3978,8 +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))
@@ -3997,13 +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;
@@ -4046,9 +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;
@@ -4073,7 +4062,7 @@ compute_avail (void)
 
                      vn_reference_lookup (gimple_assign_rhs1 (stmt),
                                           gimple_vuse (stmt),
-                                          true, &ref);
+                                          VN_WALK, &ref);
                      if (!ref)
                        continue;
 
@@ -4164,6 +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;
@@ -4174,27 +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),
@@ -4232,6 +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;
                }
 
@@ -4253,6 +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))
@@ -4281,14 +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");
                    }
                }
            }
@@ -4296,14 +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
@@ -4345,13 +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 ");
@@ -4361,13 +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
@@ -4486,8 +4545,10 @@ eliminate (void)
          gsi = gsi_for_stmt (stmt);
          unlink_stmt_vdef (stmt);
          gsi_remove (&gsi, true);
-         if (gimple_purge_dead_eh_edges (bb))
-           todo |= TODO_cleanup_cfg;
+         /* ???  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);
@@ -4495,6 +4556,13 @@ eliminate (void)
     }
   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;
 }
 
@@ -4746,14 +4814,19 @@ 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)
 {
+  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);
   BITMAP_FREE (inserted_exprs);
@@ -4769,16 +4842,22 @@ fini_pre (bool do_fre)
 
   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
@@ -4796,7 +4875,7 @@ execute_pre (bool do_fre)
   if (!do_fre)
     loop_optimizer_init (LOOPS_NORMAL);
 
-  if (!run_scc_vn ())
+  if (!run_scc_vn (do_fre ? VN_WALKREWRITE : VN_WALK))
     {
       if (!do_fre)
        loop_optimizer_finalize ();
@@ -4847,15 +4926,34 @@ execute_pre (bool do_fre)
   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);
 
   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;
 }
@@ -4890,8 +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 */
  }
 };
 
@@ -4925,6 +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 */
  }
 };