--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/c1/c1_Canonicalizer.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,877 @@
+/*
+ * Copyright 1999-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_c1_Canonicalizer.cpp.incl"
+
+
+static void do_print_value(Value* vp) {
+  (*vp)->print_line();
+}
+
+void Canonicalizer::set_canonical(Value x) {
+  assert(x != NULL, "value must exist");
+  // Note: we can not currently substitute root nodes which show up in
+  // the instruction stream (because the instruction list is embedded
+  // in the instructions).
+  if (canonical() != x) {
+    if (PrintCanonicalization) {
+      canonical()->input_values_do(do_print_value);
+      canonical()->print_line();
+      tty->print_cr("canonicalized to:");
+      x->input_values_do(do_print_value);
+      x->print_line();
+      tty->cr();
+    }
+    assert(_canonical->type()->tag() == x->type()->tag(), "types must match");
+    _canonical = x;
+  }
+}
+
+
+void Canonicalizer::move_const_to_right(Op2* x) {
+  if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands();
+}
+
+
+void Canonicalizer::do_Op2(Op2* x) {
+  if (x->x() == x->y()) {
+    switch (x->op()) {
+    case Bytecodes::_isub: set_constant(0); return;
+    case Bytecodes::_lsub: set_constant(jlong_cast(0)); return;
+    case Bytecodes::_iand: // fall through
+    case Bytecodes::_land: // fall through
+    case Bytecodes::_ior:  // fall through
+    case Bytecodes::_lor : set_canonical(x->x()); return;
+    case Bytecodes::_ixor: set_constant(0); return;
+    case Bytecodes::_lxor: set_constant(jlong_cast(0)); return;
+    }
+  }
+
+  if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
+    // do constant folding for selected operations
+    switch (x->type()->tag()) {
+      case intTag:
+        { jint a = x->x()->type()->as_IntConstant()->value();
+          jint b = x->y()->type()->as_IntConstant()->value();
+          switch (x->op()) {
+            case Bytecodes::_iadd: set_constant(a + b); return;
+            case Bytecodes::_isub: set_constant(a - b); return;
+            case Bytecodes::_imul: set_constant(a * b); return;
+            case Bytecodes::_idiv:
+              if (b != 0) {
+                if (a == min_jint && b == -1) {
+                  set_constant(min_jint);
+                } else {
+                  set_constant(a / b);
+                }
+                return;
+              }
+              break;
+            case Bytecodes::_irem:
+              if (b != 0) {
+                if (a == min_jint && b == -1) {
+                  set_constant(0);
+                } else {
+                  set_constant(a % b);
+                }
+                return;
+              }
+              break;
+            case Bytecodes::_iand: set_constant(a & b); return;
+            case Bytecodes::_ior : set_constant(a | b); return;
+            case Bytecodes::_ixor: set_constant(a ^ b); return;
+          }
+        }
+        break;
+      case longTag:
+        { jlong a = x->x()->type()->as_LongConstant()->value();
+          jlong b = x->y()->type()->as_LongConstant()->value();
+          switch (x->op()) {
+            case Bytecodes::_ladd: set_constant(a + b); return;
+            case Bytecodes::_lsub: set_constant(a - b); return;
+            case Bytecodes::_lmul: set_constant(a * b); return;
+            case Bytecodes::_ldiv:
+              if (b != 0) {
+                set_constant(SharedRuntime::ldiv(b, a));
+                return;
+              }
+              break;
+            case Bytecodes::_lrem:
+              if (b != 0) {
+                set_constant(SharedRuntime::lrem(b, a));
+                return;
+              }
+              break;
+            case Bytecodes::_land: set_constant(a & b); return;
+            case Bytecodes::_lor : set_constant(a | b); return;
+            case Bytecodes::_lxor: set_constant(a ^ b); return;
+          }
+        }
+        break;
+      // other cases not implemented (must be extremely careful with floats & doubles!)
+    }
+  }
+  // make sure constant is on the right side, if any
+  move_const_to_right(x);
+
+  if (x->y()->type()->is_constant()) {
+    // do constant folding for selected operations
+    switch (x->type()->tag()) {
+      case intTag:
+        if (x->y()->type()->as_IntConstant()->value() == 0) {
+          switch (x->op()) {
+            case Bytecodes::_iadd: set_canonical(x->x()); return;
+            case Bytecodes::_isub: set_canonical(x->x()); return;
+            case Bytecodes::_imul: set_constant(0); return;
+              // Note: for div and rem, make sure that C semantics
+              //       corresponds to Java semantics!
+            case Bytecodes::_iand: set_constant(0); return;
+            case Bytecodes::_ior : set_canonical(x->x()); return;
+          }
+        }
+        break;
+      case longTag:
+        if (x->y()->type()->as_LongConstant()->value() == (jlong)0) {
+          switch (x->op()) {
+            case Bytecodes::_ladd: set_canonical(x->x()); return;
+            case Bytecodes::_lsub: set_canonical(x->x()); return;
+            case Bytecodes::_lmul: set_constant((jlong)0); return;
+              // Note: for div and rem, make sure that C semantics
+              //       corresponds to Java semantics!
+            case Bytecodes::_land: set_constant((jlong)0); return;
+            case Bytecodes::_lor : set_canonical(x->x()); return;
+          }
+        }
+        break;
+    }
+  }
+}
+
+
+void Canonicalizer::do_Phi            (Phi*             x) {}
+void Canonicalizer::do_Constant       (Constant*        x) {}
+void Canonicalizer::do_Local          (Local*           x) {}
+void Canonicalizer::do_LoadField      (LoadField*       x) {}
+
+// checks if v is in the block that is currently processed by
+// GraphBuilder. This is the only block that has not BlockEnd yet.
+static bool in_current_block(Value v) {
+  int max_distance = 4;
+  while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) {
+    v = v->next();
+    max_distance--;
+  }
+  return v == NULL;
+}
+
+void Canonicalizer::do_StoreField     (StoreField*      x) {
+  // If a value is going to be stored into a field or array some of
+  // the conversions emitted by javac are unneeded because the fields
+  // are packed to their natural size.
+  Convert* conv = x->value()->as_Convert();
+  if (conv) {
+    Value value = NULL;
+    BasicType type = x->field()->type()->basic_type();
+    switch (conv->op()) {
+    case Bytecodes::_i2b: if (type == T_BYTE)  value = conv->value(); break;
+    case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
+    case Bytecodes::_i2c: if (type == T_CHAR  || type == T_BYTE)  value = conv->value(); break;
+    }
+    // limit this optimization to current block
+    if (value != NULL && in_current_block(conv)) {
+      set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(),
+                                   x->lock_stack(), x->state_before(), x->is_loaded(), x->is_initialized()));
+      return;
+    }
+  }
+
+}
+
+void Canonicalizer::do_ArrayLength    (ArrayLength*     x) {
+  NewArray* array = x->array()->as_NewArray();
+  if (array != NULL && array->length() != NULL) {
+    Constant* length = array->length()->as_Constant();
+    if (length != NULL) {
+      // do not use the Constant itself, but create a new Constant
+      // with same value Otherwise a Constant is live over multiple
+      // blocks without being registered in a state array.
+      assert(length->type()->as_IntConstant() != NULL, "array length must be integer");
+      set_constant(length->type()->as_IntConstant()->value());
+    }
+  } else {
+    LoadField* lf = x->array()->as_LoadField();
+    if (lf != NULL && lf->field()->is_constant()) {
+      ciObject* c = lf->field()->constant_value().as_object();
+      if (c->is_array()) {
+        ciArray* array = (ciArray*) c;
+        set_constant(array->length());
+      }
+    }
+  }
+}
+
+void Canonicalizer::do_LoadIndexed    (LoadIndexed*     x) {}
+void Canonicalizer::do_StoreIndexed   (StoreIndexed*    x) {
+  // If a value is going to be stored into a field or array some of
+  // the conversions emitted by javac are unneeded because the fields
+  // are packed to their natural size.
+  Convert* conv = x->value()->as_Convert();
+  if (conv) {
+    Value value = NULL;
+    BasicType type = x->elt_type();
+    switch (conv->op()) {
+    case Bytecodes::_i2b: if (type == T_BYTE)  value = conv->value(); break;
+    case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
+    case Bytecodes::_i2c: if (type == T_CHAR  || type == T_BYTE) value = conv->value(); break;
+    }
+    // limit this optimization to current block
+    if (value != NULL && in_current_block(conv)) {
+      set_canonical(new StoreIndexed(x->array(), x->index(), x->length(),
+                                     x->elt_type(), value, x->lock_stack()));
+      return;
+    }
+  }
+
+
+}
+
+
+void Canonicalizer::do_NegateOp(NegateOp* x) {
+  ValueType* t = x->x()->type();
+  if (t->is_constant()) {
+    switch (t->tag()) {
+      case intTag   : set_constant(-t->as_IntConstant   ()->value()); return;
+      case longTag  : set_constant(-t->as_LongConstant  ()->value()); return;
+      case floatTag : set_constant(-t->as_FloatConstant ()->value()); return;
+      case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return;
+      default       : ShouldNotReachHere();
+    }
+  }
+}
+
+
+void Canonicalizer::do_ArithmeticOp   (ArithmeticOp*    x) { do_Op2(x); }
+
+
+void Canonicalizer::do_ShiftOp        (ShiftOp*         x) {
+  ValueType* t = x->x()->type();
+  ValueType* t2 = x->y()->type();
+  if (t->is_constant()) {
+    switch (t->tag()) {
+    case intTag   : if (t->as_IntConstant()->value() == 0)         { set_constant(0); return; } break;
+    case longTag  : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break;
+    default       : ShouldNotReachHere();
+    }
+    if (t2->is_constant()) {
+      if (t->tag() == intTag) {
+        int value = t->as_IntConstant()->value();
+        int shift = t2->as_IntConstant()->value() & 31;
+        jint mask = ~(~0 << (32 - shift));
+        if (shift == 0) mask = ~0;
+        switch (x->op()) {
+          case Bytecodes::_ishl:  set_constant(value << shift); return;
+          case Bytecodes::_ishr:  set_constant(value >> shift); return;
+          case Bytecodes::_iushr: set_constant((value >> shift) & mask); return;
+        }
+      } else if (t->tag() == longTag) {
+        jlong value = t->as_LongConstant()->value();
+        int shift = t2->as_IntConstant()->value() & 63;
+        jlong mask = ~(~jlong_cast(0) << (64 - shift));
+        if (shift == 0) mask = ~jlong_cast(0);
+        switch (x->op()) {
+          case Bytecodes::_lshl:  set_constant(value << shift); return;
+          case Bytecodes::_lshr:  set_constant(value >> shift); return;
+          case Bytecodes::_lushr: set_constant((value >> shift) & mask); return;
+        }
+      }
+    }
+  }
+  if (t2->is_constant()) {
+    switch (t2->tag()) {
+      case intTag   : if (t2->as_IntConstant()->value() == 0)  set_canonical(x->x()); return;
+      case longTag  : if (t2->as_IntConstant()->value() == 0)  set_canonical(x->x()); return;
+      default       : ShouldNotReachHere();
+    }
+  }
+}
+
+
+void Canonicalizer::do_LogicOp        (LogicOp*         x) { do_Op2(x); }
+void Canonicalizer::do_CompareOp      (CompareOp*       x) {
+  if (x->x() == x->y()) {
+    switch (x->x()->type()->tag()) {
+      case longTag: set_constant(0); break;
+      case floatTag: {
+        FloatConstant* fc = x->x()->type()->as_FloatConstant();
+        if (fc) {
+          if (g_isnan(fc->value())) {
+            set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
+          } else {
+            set_constant(0);
+          }
+        }
+        break;
+      }
+      case doubleTag: {
+        DoubleConstant* dc = x->x()->type()->as_DoubleConstant();
+        if (dc) {
+          if (g_isnan(dc->value())) {
+            set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
+          } else {
+            set_constant(0);
+          }
+        }
+        break;
+      }
+    }
+  } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
+    switch (x->x()->type()->tag()) {
+      case longTag: {
+        jlong vx = x->x()->type()->as_LongConstant()->value();
+        jlong vy = x->y()->type()->as_LongConstant()->value();
+        if (vx == vy)
+          set_constant(0);
+        else if (vx < vy)
+          set_constant(-1);
+        else
+          set_constant(1);
+        break;
+      }
+
+      case floatTag: {
+        float vx = x->x()->type()->as_FloatConstant()->value();
+        float vy = x->y()->type()->as_FloatConstant()->value();
+        if (g_isnan(vx) || g_isnan(vy))
+          set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
+        else if (vx == vy)
+          set_constant(0);
+        else if (vx < vy)
+          set_constant(-1);
+        else
+          set_constant(1);
+        break;
+      }
+
+      case doubleTag: {
+        double vx = x->x()->type()->as_DoubleConstant()->value();
+        double vy = x->y()->type()->as_DoubleConstant()->value();
+        if (g_isnan(vx) || g_isnan(vy))
+          set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
+        else if (vx == vy)
+          set_constant(0);
+        else if (vx < vy)
+          set_constant(-1);
+        else
+          set_constant(1);
+        break;
+      }
+    }
+
+  }
+}
+
+
+void Canonicalizer::do_IfInstanceOf(IfInstanceOf*    x) {}
+
+void Canonicalizer::do_IfOp(IfOp* x) {
+  // Caution: do not use do_Op2(x) here for now since
+  //          we map the condition to the op for now!
+  move_const_to_right(x);
+}
+
+
+void Canonicalizer::do_Intrinsic      (Intrinsic*       x) {
+  switch (x->id()) {
+  case vmIntrinsics::_floatToRawIntBits   : {
+    FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant();
+    if (c != NULL) {
+      JavaValue v;
+      v.set_jfloat(c->value());
+      set_constant(v.get_jint());
+    }
+    break;
+  }
+  case vmIntrinsics::_intBitsToFloat      : {
+    IntConstant* c = x->argument_at(0)->type()->as_IntConstant();
+    if (c != NULL) {
+      JavaValue v;
+      v.set_jint(c->value());
+      set_constant(v.get_jfloat());
+    }
+    break;
+  }
+  case vmIntrinsics::_doubleToRawLongBits : {
+    DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant();
+    if (c != NULL) {
+      JavaValue v;
+      v.set_jdouble(c->value());
+      set_constant(v.get_jlong());
+    }
+    break;
+  }
+  case vmIntrinsics::_longBitsToDouble    : {
+    LongConstant* c = x->argument_at(0)->type()->as_LongConstant();
+    if (c != NULL) {
+      JavaValue v;
+      v.set_jlong(c->value());
+      set_constant(v.get_jdouble());
+    }
+    break;
+  }
+  }
+}
+
+void Canonicalizer::do_Convert        (Convert*         x) {
+  if (x->value()->type()->is_constant()) {
+    switch (x->op()) {
+    case Bytecodes::_i2b:  set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break;
+    case Bytecodes::_i2s:  set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break;
+    case Bytecodes::_i2c:  set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break;
+    case Bytecodes::_i2l:  set_constant((jlong)(x->value()->type()->as_IntConstant()->value()));             break;
+    case Bytecodes::_i2f:  set_constant((float)(x->value()->type()->as_IntConstant()->value()));             break;
+    case Bytecodes::_i2d:  set_constant((double)(x->value()->type()->as_IntConstant()->value()));            break;
+    case Bytecodes::_l2i:  set_constant((int)(x->value()->type()->as_LongConstant()->value()));              break;
+    case Bytecodes::_l2f:  set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break;
+    case Bytecodes::_l2d:  set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break;
+    case Bytecodes::_f2d:  set_constant((double)(x->value()->type()->as_FloatConstant()->value()));          break;
+    case Bytecodes::_f2i:  set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break;
+    case Bytecodes::_f2l:  set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break;
+    case Bytecodes::_d2f:  set_constant((float)(x->value()->type()->as_DoubleConstant()->value()));          break;
+    case Bytecodes::_d2i:  set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break;
+    case Bytecodes::_d2l:  set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break;
+    default:
+      ShouldNotReachHere();
+    }
+  }
+
+  Value value = x->value();
+  BasicType type = T_ILLEGAL;
+  LoadField* lf = value->as_LoadField();
+  if (lf) {
+    type = lf->field_type();
+  } else {
+    LoadIndexed* li = value->as_LoadIndexed();
+    if (li) {
+      type = li->elt_type();
+    } else {
+      Convert* conv = value->as_Convert();
+      if (conv) {
+        switch (conv->op()) {
+          case Bytecodes::_i2b: type = T_BYTE;  break;
+          case Bytecodes::_i2s: type = T_SHORT; break;
+          case Bytecodes::_i2c: type = T_CHAR;  break;
+        }
+      }
+    }
+  }
+  if (type != T_ILLEGAL) {
+    switch (x->op()) {
+      case Bytecodes::_i2b: if (type == T_BYTE)                    set_canonical(x->value()); break;
+      case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break;
+      case Bytecodes::_i2c: if (type == T_CHAR)                    set_canonical(x->value()); break;
+    }
+  } else {
+    Op2* op2 = x->value()->as_Op2();
+    if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) {
+      jint safebits = 0;
+      jint mask = op2->y()->type()->as_IntConstant()->value();
+      switch (x->op()) {
+        case Bytecodes::_i2b: safebits = 0x7f;   break;
+        case Bytecodes::_i2s: safebits = 0x7fff; break;
+        case Bytecodes::_i2c: safebits = 0xffff; break;
+      }
+      // When casting a masked integer to a smaller signed type, if
+      // the mask doesn't include the sign bit the cast isn't needed.
+      if (safebits && (mask & ~safebits) == 0) {
+        set_canonical(x->value());
+      }
+    }
+  }
+
+}
+
+void Canonicalizer::do_NullCheck      (NullCheck*       x) {
+  if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) {
+    set_canonical(x->obj());
+  } else {
+    Constant* con = x->obj()->as_Constant();
+    if (con) {
+      ObjectType* c = con->type()->as_ObjectType();
+      if (c && c->is_loaded()) {
+        ObjectConstant* oc = c->as_ObjectConstant();
+        if (!oc || !oc->value()->is_null_object()) {
+          set_canonical(con);
+        }
+      }
+    }
+  }
+}
+
+void Canonicalizer::do_Invoke         (Invoke*          x) {}
+void Canonicalizer::do_NewInstance    (NewInstance*     x) {}
+void Canonicalizer::do_NewTypeArray   (NewTypeArray*    x) {}
+void Canonicalizer::do_NewObjectArray (NewObjectArray*  x) {}
+void Canonicalizer::do_NewMultiArray  (NewMultiArray*   x) {}
+void Canonicalizer::do_CheckCast      (CheckCast*       x) {
+  if (x->klass()->is_loaded()) {
+    Value obj = x->obj();
+    ciType* klass = obj->exact_type();
+    if (klass == NULL) klass = obj->declared_type();
+    if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) {
+      set_canonical(obj);
+      return;
+    }
+    // checkcast of null returns null
+    if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
+      set_canonical(obj);
+    }
+  }
+}
+void Canonicalizer::do_InstanceOf     (InstanceOf*      x) {
+  if (x->klass()->is_loaded()) {
+    Value obj = x->obj();
+    ciType* exact = obj->exact_type();
+    if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) {
+      set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0);
+      return;
+    }
+    // instanceof null returns false
+    if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
+      set_constant(0);
+    }
+  }
+
+}
+void Canonicalizer::do_MonitorEnter   (MonitorEnter*    x) {}
+void Canonicalizer::do_MonitorExit    (MonitorExit*     x) {}
+void Canonicalizer::do_BlockBegin     (BlockBegin*      x) {}
+void Canonicalizer::do_Goto           (Goto*            x) {}
+
+
+static bool is_true(jlong x, If::Condition cond, jlong y) {
+  switch (cond) {
+    case If::eql: return x == y;
+    case If::neq: return x != y;
+    case If::lss: return x <  y;
+    case If::leq: return x <= y;
+    case If::gtr: return x >  y;
+    case If::geq: return x >= y;
+  }
+  ShouldNotReachHere();
+  return false;
+}
+
+
+void Canonicalizer::do_If(If* x) {
+  // move const to right
+  if (x->x()->type()->is_constant()) x->swap_operands();
+  // simplify
+  const Value l = x->x(); ValueType* lt = l->type();
+  const Value r = x->y(); ValueType* rt = r->type();
+
+  if (l == r && !lt->is_float_kind()) {
+    // pattern: If (a cond a) => simplify to Goto
+    BlockBegin* sux;
+    switch (x->cond()) {
+    case If::eql: sux = x->sux_for(true);  break;
+    case If::neq: sux = x->sux_for(false); break;
+    case If::lss: sux = x->sux_for(false); break;
+    case If::leq: sux = x->sux_for(true);  break;
+    case If::gtr: sux = x->sux_for(false); break;
+    case If::geq: sux = x->sux_for(true);  break;
+    }
+    // If is a safepoint then the debug information should come from the state_before of the If.
+    set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
+    return;
+  }
+
+  if (lt->is_constant() && rt->is_constant()) {
+    if (x->x()->as_Constant() != NULL) {
+      // pattern: If (lc cond rc) => simplify to: Goto
+      BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(),
+                                                       x->sux_for(true),
+                                                       x->sux_for(false));
+      if (sux != NULL) {
+        // If is a safepoint then the debug information should come from the state_before of the If.
+        set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
+      }
+    }
+  } else if (rt->as_IntConstant() != NULL) {
+    // pattern: If (l cond rc) => investigate further
+    const jint rc = rt->as_IntConstant()->value();
+    if (l->as_CompareOp() != NULL) {
+      // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto
+      CompareOp* cmp = l->as_CompareOp();
+      bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl;
+      BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b
+      BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b
+      BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b
+      BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered
+      // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are
+      //       equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either
+      //       lss_sux or gtr_sux.
+      if (lss_sux == eql_sux && eql_sux == gtr_sux) {
+        // all successors identical => simplify to: Goto
+        set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint()));
+      } else {
+        // two successors differ and two successors are the same => simplify to: If (x cmp y)
+        // determine new condition & successors
+        If::Condition cond;
+        BlockBegin* tsux = NULL;
+        BlockBegin* fsux = NULL;
+             if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; }
+        else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; }
+        else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; }
+        else                         { ShouldNotReachHere();                           }
+           If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint());
+        if (cmp->x() == cmp->y()) {
+          do_If(canon);
+        } else {
+          set_canonical(canon);
+          set_bci(cmp->bci());
+        }
+      }
+    } else if (l->as_InstanceOf() != NULL) {
+      // NOTE: Code permanently disabled for now since it leaves the old InstanceOf
+      //       instruction in the graph (it is pinned). Need to fix this at some point.
+      return;
+      // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto
+      InstanceOf* inst = l->as_InstanceOf();
+      BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1
+      BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0
+      if (is_inst_sux == no_inst_sux && inst->is_loaded()) {
+        // both successors identical and klass is loaded => simplify to: Goto
+        set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint()));
+      } else {
+        // successors differ => simplify to: IfInstanceOf
+        set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->bci(), is_inst_sux, no_inst_sux));
+      }
+    }
+  } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) {
+    if (x->cond() == Instruction::eql) {
+      set_canonical(new Goto(x->fsux(), x->state_before(), x->is_safepoint()));
+    } else {
+      assert(x->cond() == Instruction::neq, "only other valid case");
+      set_canonical(new Goto(x->tsux(), x->state_before(), x->is_safepoint()));
+    }
+  }
+}
+
+
+void Canonicalizer::do_TableSwitch(TableSwitch* x) {
+  if (x->tag()->type()->is_constant()) {
+    int v = x->tag()->type()->as_IntConstant()->value();
+    BlockBegin* sux = x->default_sux();
+    if (v >= x->lo_key() && v <= x->hi_key()) {
+      sux = x->sux_at(v - x->lo_key());
+    }
+    set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
+  } else if (x->number_of_sux() == 1) {
+    // NOTE: Code permanently disabled for now since the switch statement's
+    //       tag expression may produce side-effects in which case it must
+    //       be executed.
+    return;
+    // simplify to Goto
+    set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
+  } else if (x->number_of_sux() == 2) {
+    // NOTE: Code permanently disabled for now since it produces two new nodes
+    //       (Constant & If) and the Canonicalizer cannot return them correctly
+    //       yet. For now we copied the corresponding code directly into the
+    //       GraphBuilder (i.e., we should never reach here).
+    return;
+    // simplify to If
+    assert(x->lo_key() == x->hi_key(), "keys must be the same");
+    Constant* key = new Constant(new IntConstant(x->lo_key()));
+    set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
+  }
+}
+
+
+void Canonicalizer::do_LookupSwitch(LookupSwitch* x) {
+  if (x->tag()->type()->is_constant()) {
+    int v = x->tag()->type()->as_IntConstant()->value();
+    BlockBegin* sux = x->default_sux();
+    for (int i = 0; i < x->length(); i++) {
+      if (v == x->key_at(i)) {
+        sux = x->sux_at(i);
+      }
+    }
+    set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
+  } else if (x->number_of_sux() == 1) {
+    // NOTE: Code permanently disabled for now since the switch statement's
+    //       tag expression may produce side-effects in which case it must
+    //       be executed.
+    return;
+    // simplify to Goto
+    set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
+  } else if (x->number_of_sux() == 2) {
+    // NOTE: Code permanently disabled for now since it produces two new nodes
+    //       (Constant & If) and the Canonicalizer cannot return them correctly
+    //       yet. For now we copied the corresponding code directly into the
+    //       GraphBuilder (i.e., we should never reach here).
+    return;
+    // simplify to If
+    assert(x->length() == 1, "length must be the same");
+    Constant* key = new Constant(new IntConstant(x->key_at(0)));
+    set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
+  }
+}
+
+
+void Canonicalizer::do_Return         (Return*          x) {}
+void Canonicalizer::do_Throw          (Throw*           x) {}
+void Canonicalizer::do_Base           (Base*            x) {}
+void Canonicalizer::do_OsrEntry       (OsrEntry*        x) {}
+void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {}
+
+static bool match_index_and_scale(Instruction*  instr,
+                                  Instruction** index,
+                                  int*          log2_scale,
+                                  Instruction** instr_to_unpin) {
+  *instr_to_unpin = NULL;
+
+  // Skip conversion ops
+  Convert* convert = instr->as_Convert();
+  if (convert != NULL) {
+    instr = convert->value();
+  }
+
+  ShiftOp* shift = instr->as_ShiftOp();
+  if (shift != NULL) {
+    if (shift->is_pinned()) {
+      *instr_to_unpin = shift;
+    }
+    // Constant shift value?
+    Constant* con = shift->y()->as_Constant();
+    if (con == NULL) return false;
+    // Well-known type and value?
+    IntConstant* val = con->type()->as_IntConstant();
+    if (val == NULL) return false;
+    if (shift->x()->type() != intType) return false;
+    *index = shift->x();
+    int tmp_scale = val->value();
+    if (tmp_scale >= 0 && tmp_scale < 4) {
+      *log2_scale = tmp_scale;
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  ArithmeticOp* arith = instr->as_ArithmeticOp();
+  if (arith != NULL) {
+    if (arith->is_pinned()) {
+      *instr_to_unpin = arith;
+    }
+    // Check for integer multiply
+    if (arith->op() == Bytecodes::_imul) {
+      // See if either arg is a known constant
+      Constant* con = arith->x()->as_Constant();
+      if (con != NULL) {
+        *index = arith->y();
+      } else {
+        con = arith->y()->as_Constant();
+        if (con == NULL) return false;
+        *index = arith->x();
+      }
+      if ((*index)->type() != intType) return false;
+      // Well-known type and value?
+      IntConstant* val = con->type()->as_IntConstant();
+      if (val == NULL) return false;
+      switch (val->value()) {
+      case 1: *log2_scale = 0; return true;
+      case 2: *log2_scale = 1; return true;
+      case 4: *log2_scale = 2; return true;
+      case 8: *log2_scale = 3; return true;
+      default:            return false;
+      }
+    }
+  }
+
+  // Unknown instruction sequence; don't touch it
+  return false;
+}
+
+
+static bool match(UnsafeRawOp* x,
+                  Instruction** base,
+                  Instruction** index,
+                  int*          log2_scale) {
+  Instruction* instr_to_unpin = NULL;
+  ArithmeticOp* root = x->base()->as_ArithmeticOp();
+  if (root == NULL) return false;
+  // Limit ourselves to addition for now
+  if (root->op() != Bytecodes::_ladd) return false;
+  // Try to find shift or scale op
+  if (match_index_and_scale(root->y(), index, log2_scale, &instr_to_unpin)) {
+    *base = root->x();
+  } else if (match_index_and_scale(root->x(), index, log2_scale, &instr_to_unpin)) {
+    *base = root->y();
+  } else if (root->y()->as_Convert() != NULL) {
+    Convert* convert = root->y()->as_Convert();
+    if (convert->op() == Bytecodes::_i2l && convert->value()->type() == intType) {
+      // pick base and index, setting scale at 1
+      *base  = root->x();
+      *index = convert->value();
+      *log2_scale = 0;
+    } else {
+      return false;
+    }
+  } else {
+    // doesn't match any expected sequences
+    return false;
+  }
+
+  // If the value is pinned then it will be always be computed so
+  // there's no profit to reshaping the expression.
+  return !root->is_pinned();
+}
+
+
+void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) {
+  Instruction* base = NULL;
+  Instruction* index = NULL;
+  int          log2_scale;
+
+  if (match(x, &base, &index, &log2_scale)) {
+    x->set_base(base);
+    x->set_index(index);
+    x->set_log2_scale(log2_scale);
+    if (PrintUnsafeOptimization) {
+      tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d",
+                    x->id(), x->base()->id(), x->index()->id(), x->log2_scale());
+    }
+  }
+}
+
+void Canonicalizer::do_RoundFP(RoundFP* x) {}
+void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
+void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
+void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {}
+void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {}
+void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead*  x) {}
+void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {}
+void Canonicalizer::do_ProfileCall(ProfileCall* x) {}
+void Canonicalizer::do_ProfileCounter(ProfileCounter* x) {}