duke@435: /*
trims@1907:  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: #include "incls/_precompiled.incl"
duke@435: #include "incls/_c1_Canonicalizer.cpp.incl"
duke@435: 
duke@435: 
iveresov@1939: class PrintValueVisitor: public ValueVisitor {
iveresov@1939:   void visit(Value* vp) {
iveresov@1939:     (*vp)->print_line();
iveresov@1939:   }
iveresov@1939: };
duke@435: 
duke@435: void Canonicalizer::set_canonical(Value x) {
duke@435:   assert(x != NULL, "value must exist");
duke@435:   // Note: we can not currently substitute root nodes which show up in
duke@435:   // the instruction stream (because the instruction list is embedded
duke@435:   // in the instructions).
duke@435:   if (canonical() != x) {
duke@435:     if (PrintCanonicalization) {
iveresov@1939:       PrintValueVisitor do_print_value;
iveresov@1939:       canonical()->input_values_do(&do_print_value);
duke@435:       canonical()->print_line();
duke@435:       tty->print_cr("canonicalized to:");
iveresov@1939:       x->input_values_do(&do_print_value);
duke@435:       x->print_line();
duke@435:       tty->cr();
duke@435:     }
duke@435:     assert(_canonical->type()->tag() == x->type()->tag(), "types must match");
duke@435:     _canonical = x;
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::move_const_to_right(Op2* x) {
duke@435:   if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands();
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_Op2(Op2* x) {
duke@435:   if (x->x() == x->y()) {
duke@435:     switch (x->op()) {
duke@435:     case Bytecodes::_isub: set_constant(0); return;
duke@435:     case Bytecodes::_lsub: set_constant(jlong_cast(0)); return;
duke@435:     case Bytecodes::_iand: // fall through
duke@435:     case Bytecodes::_land: // fall through
duke@435:     case Bytecodes::_ior:  // fall through
duke@435:     case Bytecodes::_lor : set_canonical(x->x()); return;
duke@435:     case Bytecodes::_ixor: set_constant(0); return;
duke@435:     case Bytecodes::_lxor: set_constant(jlong_cast(0)); return;
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
duke@435:     // do constant folding for selected operations
duke@435:     switch (x->type()->tag()) {
duke@435:       case intTag:
duke@435:         { jint a = x->x()->type()->as_IntConstant()->value();
duke@435:           jint b = x->y()->type()->as_IntConstant()->value();
duke@435:           switch (x->op()) {
duke@435:             case Bytecodes::_iadd: set_constant(a + b); return;
duke@435:             case Bytecodes::_isub: set_constant(a - b); return;
duke@435:             case Bytecodes::_imul: set_constant(a * b); return;
duke@435:             case Bytecodes::_idiv:
duke@435:               if (b != 0) {
duke@435:                 if (a == min_jint && b == -1) {
duke@435:                   set_constant(min_jint);
duke@435:                 } else {
duke@435:                   set_constant(a / b);
duke@435:                 }
duke@435:                 return;
duke@435:               }
duke@435:               break;
duke@435:             case Bytecodes::_irem:
duke@435:               if (b != 0) {
duke@435:                 if (a == min_jint && b == -1) {
duke@435:                   set_constant(0);
duke@435:                 } else {
duke@435:                   set_constant(a % b);
duke@435:                 }
duke@435:                 return;
duke@435:               }
duke@435:               break;
duke@435:             case Bytecodes::_iand: set_constant(a & b); return;
duke@435:             case Bytecodes::_ior : set_constant(a | b); return;
duke@435:             case Bytecodes::_ixor: set_constant(a ^ b); return;
duke@435:           }
duke@435:         }
duke@435:         break;
duke@435:       case longTag:
duke@435:         { jlong a = x->x()->type()->as_LongConstant()->value();
duke@435:           jlong b = x->y()->type()->as_LongConstant()->value();
duke@435:           switch (x->op()) {
duke@435:             case Bytecodes::_ladd: set_constant(a + b); return;
duke@435:             case Bytecodes::_lsub: set_constant(a - b); return;
duke@435:             case Bytecodes::_lmul: set_constant(a * b); return;
duke@435:             case Bytecodes::_ldiv:
duke@435:               if (b != 0) {
duke@435:                 set_constant(SharedRuntime::ldiv(b, a));
duke@435:                 return;
duke@435:               }
duke@435:               break;
duke@435:             case Bytecodes::_lrem:
duke@435:               if (b != 0) {
duke@435:                 set_constant(SharedRuntime::lrem(b, a));
duke@435:                 return;
duke@435:               }
duke@435:               break;
duke@435:             case Bytecodes::_land: set_constant(a & b); return;
duke@435:             case Bytecodes::_lor : set_constant(a | b); return;
duke@435:             case Bytecodes::_lxor: set_constant(a ^ b); return;
duke@435:           }
duke@435:         }
duke@435:         break;
duke@435:       // other cases not implemented (must be extremely careful with floats & doubles!)
duke@435:     }
duke@435:   }
duke@435:   // make sure constant is on the right side, if any
duke@435:   move_const_to_right(x);
duke@435: 
duke@435:   if (x->y()->type()->is_constant()) {
duke@435:     // do constant folding for selected operations
duke@435:     switch (x->type()->tag()) {
duke@435:       case intTag:
duke@435:         if (x->y()->type()->as_IntConstant()->value() == 0) {
duke@435:           switch (x->op()) {
duke@435:             case Bytecodes::_iadd: set_canonical(x->x()); return;
duke@435:             case Bytecodes::_isub: set_canonical(x->x()); return;
duke@435:             case Bytecodes::_imul: set_constant(0); return;
duke@435:               // Note: for div and rem, make sure that C semantics
duke@435:               //       corresponds to Java semantics!
duke@435:             case Bytecodes::_iand: set_constant(0); return;
duke@435:             case Bytecodes::_ior : set_canonical(x->x()); return;
duke@435:           }
duke@435:         }
duke@435:         break;
duke@435:       case longTag:
duke@435:         if (x->y()->type()->as_LongConstant()->value() == (jlong)0) {
duke@435:           switch (x->op()) {
duke@435:             case Bytecodes::_ladd: set_canonical(x->x()); return;
duke@435:             case Bytecodes::_lsub: set_canonical(x->x()); return;
duke@435:             case Bytecodes::_lmul: set_constant((jlong)0); return;
duke@435:               // Note: for div and rem, make sure that C semantics
duke@435:               //       corresponds to Java semantics!
duke@435:             case Bytecodes::_land: set_constant((jlong)0); return;
duke@435:             case Bytecodes::_lor : set_canonical(x->x()); return;
duke@435:           }
duke@435:         }
duke@435:         break;
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_Phi            (Phi*             x) {}
duke@435: void Canonicalizer::do_Constant       (Constant*        x) {}
duke@435: void Canonicalizer::do_Local          (Local*           x) {}
duke@435: void Canonicalizer::do_LoadField      (LoadField*       x) {}
duke@435: 
duke@435: // checks if v is in the block that is currently processed by
duke@435: // GraphBuilder. This is the only block that has not BlockEnd yet.
duke@435: static bool in_current_block(Value v) {
duke@435:   int max_distance = 4;
duke@435:   while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) {
duke@435:     v = v->next();
duke@435:     max_distance--;
duke@435:   }
duke@435:   return v == NULL;
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_StoreField     (StoreField*      x) {
duke@435:   // If a value is going to be stored into a field or array some of
duke@435:   // the conversions emitted by javac are unneeded because the fields
duke@435:   // are packed to their natural size.
duke@435:   Convert* conv = x->value()->as_Convert();
duke@435:   if (conv) {
duke@435:     Value value = NULL;
duke@435:     BasicType type = x->field()->type()->basic_type();
duke@435:     switch (conv->op()) {
duke@435:     case Bytecodes::_i2b: if (type == T_BYTE)  value = conv->value(); break;
duke@435:     case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
duke@435:     case Bytecodes::_i2c: if (type == T_CHAR  || type == T_BYTE)  value = conv->value(); break;
duke@435:     }
duke@435:     // limit this optimization to current block
duke@435:     if (value != NULL && in_current_block(conv)) {
duke@435:       set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(),
iveresov@1939:                                        x->lock_stack(), x->state_before(), x->is_loaded(), x->is_initialized()));
duke@435:       return;
duke@435:     }
duke@435:   }
duke@435: 
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_ArrayLength    (ArrayLength*     x) {
duke@435:   NewArray* array = x->array()->as_NewArray();
duke@435:   if (array != NULL && array->length() != NULL) {
duke@435:     Constant* length = array->length()->as_Constant();
duke@435:     if (length != NULL) {
duke@435:       // do not use the Constant itself, but create a new Constant
duke@435:       // with same value Otherwise a Constant is live over multiple
duke@435:       // blocks without being registered in a state array.
duke@435:       assert(length->type()->as_IntConstant() != NULL, "array length must be integer");
duke@435:       set_constant(length->type()->as_IntConstant()->value());
duke@435:     }
duke@435:   } else {
duke@435:     LoadField* lf = x->array()->as_LoadField();
twisti@1730:     if (lf != NULL) {
twisti@1730:       ciField* field = lf->field();
twisti@1730:       if (field->is_constant() && field->is_static()) {
twisti@1730:         // final static field
twisti@1730:         ciObject* c = field->constant_value().as_object();
twisti@1730:         if (c->is_array()) {
twisti@1730:           ciArray* array = (ciArray*) c;
twisti@1730:           set_constant(array->length());
twisti@1730:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_LoadIndexed    (LoadIndexed*     x) {}
duke@435: void Canonicalizer::do_StoreIndexed   (StoreIndexed*    x) {
duke@435:   // If a value is going to be stored into a field or array some of
duke@435:   // the conversions emitted by javac are unneeded because the fields
duke@435:   // are packed to their natural size.
duke@435:   Convert* conv = x->value()->as_Convert();
duke@435:   if (conv) {
duke@435:     Value value = NULL;
duke@435:     BasicType type = x->elt_type();
duke@435:     switch (conv->op()) {
duke@435:     case Bytecodes::_i2b: if (type == T_BYTE)  value = conv->value(); break;
duke@435:     case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
duke@435:     case Bytecodes::_i2c: if (type == T_CHAR  || type == T_BYTE) value = conv->value(); break;
duke@435:     }
duke@435:     // limit this optimization to current block
duke@435:     if (value != NULL && in_current_block(conv)) {
duke@435:       set_canonical(new StoreIndexed(x->array(), x->index(), x->length(),
duke@435:                                      x->elt_type(), value, x->lock_stack()));
duke@435:       return;
duke@435:     }
duke@435:   }
duke@435: 
duke@435: 
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_NegateOp(NegateOp* x) {
duke@435:   ValueType* t = x->x()->type();
duke@435:   if (t->is_constant()) {
duke@435:     switch (t->tag()) {
duke@435:       case intTag   : set_constant(-t->as_IntConstant   ()->value()); return;
duke@435:       case longTag  : set_constant(-t->as_LongConstant  ()->value()); return;
duke@435:       case floatTag : set_constant(-t->as_FloatConstant ()->value()); return;
duke@435:       case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return;
duke@435:       default       : ShouldNotReachHere();
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_ArithmeticOp   (ArithmeticOp*    x) { do_Op2(x); }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_ShiftOp        (ShiftOp*         x) {
duke@435:   ValueType* t = x->x()->type();
duke@435:   ValueType* t2 = x->y()->type();
duke@435:   if (t->is_constant()) {
duke@435:     switch (t->tag()) {
duke@435:     case intTag   : if (t->as_IntConstant()->value() == 0)         { set_constant(0); return; } break;
duke@435:     case longTag  : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break;
duke@435:     default       : ShouldNotReachHere();
duke@435:     }
duke@435:     if (t2->is_constant()) {
duke@435:       if (t->tag() == intTag) {
duke@435:         int value = t->as_IntConstant()->value();
duke@435:         int shift = t2->as_IntConstant()->value() & 31;
duke@435:         jint mask = ~(~0 << (32 - shift));
duke@435:         if (shift == 0) mask = ~0;
duke@435:         switch (x->op()) {
duke@435:           case Bytecodes::_ishl:  set_constant(value << shift); return;
duke@435:           case Bytecodes::_ishr:  set_constant(value >> shift); return;
duke@435:           case Bytecodes::_iushr: set_constant((value >> shift) & mask); return;
duke@435:         }
duke@435:       } else if (t->tag() == longTag) {
duke@435:         jlong value = t->as_LongConstant()->value();
duke@435:         int shift = t2->as_IntConstant()->value() & 63;
duke@435:         jlong mask = ~(~jlong_cast(0) << (64 - shift));
duke@435:         if (shift == 0) mask = ~jlong_cast(0);
duke@435:         switch (x->op()) {
duke@435:           case Bytecodes::_lshl:  set_constant(value << shift); return;
duke@435:           case Bytecodes::_lshr:  set_constant(value >> shift); return;
duke@435:           case Bytecodes::_lushr: set_constant((value >> shift) & mask); return;
duke@435:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435:   if (t2->is_constant()) {
duke@435:     switch (t2->tag()) {
duke@435:       case intTag   : if (t2->as_IntConstant()->value() == 0)  set_canonical(x->x()); return;
duke@435:       case longTag  : if (t2->as_IntConstant()->value() == 0)  set_canonical(x->x()); return;
duke@435:       default       : ShouldNotReachHere();
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_LogicOp        (LogicOp*         x) { do_Op2(x); }
duke@435: void Canonicalizer::do_CompareOp      (CompareOp*       x) {
duke@435:   if (x->x() == x->y()) {
duke@435:     switch (x->x()->type()->tag()) {
duke@435:       case longTag: set_constant(0); break;
duke@435:       case floatTag: {
duke@435:         FloatConstant* fc = x->x()->type()->as_FloatConstant();
duke@435:         if (fc) {
duke@435:           if (g_isnan(fc->value())) {
duke@435:             set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
duke@435:           } else {
duke@435:             set_constant(0);
duke@435:           }
duke@435:         }
duke@435:         break;
duke@435:       }
duke@435:       case doubleTag: {
duke@435:         DoubleConstant* dc = x->x()->type()->as_DoubleConstant();
duke@435:         if (dc) {
duke@435:           if (g_isnan(dc->value())) {
duke@435:             set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
duke@435:           } else {
duke@435:             set_constant(0);
duke@435:           }
duke@435:         }
duke@435:         break;
duke@435:       }
duke@435:     }
duke@435:   } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
duke@435:     switch (x->x()->type()->tag()) {
duke@435:       case longTag: {
duke@435:         jlong vx = x->x()->type()->as_LongConstant()->value();
duke@435:         jlong vy = x->y()->type()->as_LongConstant()->value();
duke@435:         if (vx == vy)
duke@435:           set_constant(0);
duke@435:         else if (vx < vy)
duke@435:           set_constant(-1);
duke@435:         else
duke@435:           set_constant(1);
duke@435:         break;
duke@435:       }
duke@435: 
duke@435:       case floatTag: {
duke@435:         float vx = x->x()->type()->as_FloatConstant()->value();
duke@435:         float vy = x->y()->type()->as_FloatConstant()->value();
duke@435:         if (g_isnan(vx) || g_isnan(vy))
duke@435:           set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
duke@435:         else if (vx == vy)
duke@435:           set_constant(0);
duke@435:         else if (vx < vy)
duke@435:           set_constant(-1);
duke@435:         else
duke@435:           set_constant(1);
duke@435:         break;
duke@435:       }
duke@435: 
duke@435:       case doubleTag: {
duke@435:         double vx = x->x()->type()->as_DoubleConstant()->value();
duke@435:         double vy = x->y()->type()->as_DoubleConstant()->value();
duke@435:         if (g_isnan(vx) || g_isnan(vy))
duke@435:           set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
duke@435:         else if (vx == vy)
duke@435:           set_constant(0);
duke@435:         else if (vx < vy)
duke@435:           set_constant(-1);
duke@435:         else
duke@435:           set_constant(1);
duke@435:         break;
duke@435:       }
duke@435:     }
duke@435: 
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_IfInstanceOf(IfInstanceOf*    x) {}
duke@435: 
duke@435: void Canonicalizer::do_IfOp(IfOp* x) {
duke@435:   // Caution: do not use do_Op2(x) here for now since
duke@435:   //          we map the condition to the op for now!
duke@435:   move_const_to_right(x);
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_Intrinsic      (Intrinsic*       x) {
duke@435:   switch (x->id()) {
duke@435:   case vmIntrinsics::_floatToRawIntBits   : {
duke@435:     FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant();
duke@435:     if (c != NULL) {
duke@435:       JavaValue v;
duke@435:       v.set_jfloat(c->value());
duke@435:       set_constant(v.get_jint());
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435:   case vmIntrinsics::_intBitsToFloat      : {
duke@435:     IntConstant* c = x->argument_at(0)->type()->as_IntConstant();
duke@435:     if (c != NULL) {
duke@435:       JavaValue v;
duke@435:       v.set_jint(c->value());
duke@435:       set_constant(v.get_jfloat());
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435:   case vmIntrinsics::_doubleToRawLongBits : {
duke@435:     DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant();
duke@435:     if (c != NULL) {
duke@435:       JavaValue v;
duke@435:       v.set_jdouble(c->value());
duke@435:       set_constant(v.get_jlong());
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435:   case vmIntrinsics::_longBitsToDouble    : {
duke@435:     LongConstant* c = x->argument_at(0)->type()->as_LongConstant();
duke@435:     if (c != NULL) {
duke@435:       JavaValue v;
duke@435:       v.set_jlong(c->value());
duke@435:       set_constant(v.get_jdouble());
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_Convert        (Convert*         x) {
duke@435:   if (x->value()->type()->is_constant()) {
duke@435:     switch (x->op()) {
duke@435:     case Bytecodes::_i2b:  set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break;
duke@435:     case Bytecodes::_i2s:  set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break;
duke@435:     case Bytecodes::_i2c:  set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break;
duke@435:     case Bytecodes::_i2l:  set_constant((jlong)(x->value()->type()->as_IntConstant()->value()));             break;
duke@435:     case Bytecodes::_i2f:  set_constant((float)(x->value()->type()->as_IntConstant()->value()));             break;
duke@435:     case Bytecodes::_i2d:  set_constant((double)(x->value()->type()->as_IntConstant()->value()));            break;
duke@435:     case Bytecodes::_l2i:  set_constant((int)(x->value()->type()->as_LongConstant()->value()));              break;
duke@435:     case Bytecodes::_l2f:  set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break;
duke@435:     case Bytecodes::_l2d:  set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break;
duke@435:     case Bytecodes::_f2d:  set_constant((double)(x->value()->type()->as_FloatConstant()->value()));          break;
duke@435:     case Bytecodes::_f2i:  set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break;
duke@435:     case Bytecodes::_f2l:  set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break;
duke@435:     case Bytecodes::_d2f:  set_constant((float)(x->value()->type()->as_DoubleConstant()->value()));          break;
duke@435:     case Bytecodes::_d2i:  set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break;
duke@435:     case Bytecodes::_d2l:  set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break;
duke@435:     default:
duke@435:       ShouldNotReachHere();
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   Value value = x->value();
duke@435:   BasicType type = T_ILLEGAL;
duke@435:   LoadField* lf = value->as_LoadField();
duke@435:   if (lf) {
duke@435:     type = lf->field_type();
duke@435:   } else {
duke@435:     LoadIndexed* li = value->as_LoadIndexed();
duke@435:     if (li) {
duke@435:       type = li->elt_type();
duke@435:     } else {
duke@435:       Convert* conv = value->as_Convert();
duke@435:       if (conv) {
duke@435:         switch (conv->op()) {
duke@435:           case Bytecodes::_i2b: type = T_BYTE;  break;
duke@435:           case Bytecodes::_i2s: type = T_SHORT; break;
duke@435:           case Bytecodes::_i2c: type = T_CHAR;  break;
duke@435:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435:   if (type != T_ILLEGAL) {
duke@435:     switch (x->op()) {
duke@435:       case Bytecodes::_i2b: if (type == T_BYTE)                    set_canonical(x->value()); break;
duke@435:       case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break;
duke@435:       case Bytecodes::_i2c: if (type == T_CHAR)                    set_canonical(x->value()); break;
duke@435:     }
duke@435:   } else {
duke@435:     Op2* op2 = x->value()->as_Op2();
duke@435:     if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) {
duke@435:       jint safebits = 0;
duke@435:       jint mask = op2->y()->type()->as_IntConstant()->value();
duke@435:       switch (x->op()) {
duke@435:         case Bytecodes::_i2b: safebits = 0x7f;   break;
duke@435:         case Bytecodes::_i2s: safebits = 0x7fff; break;
duke@435:         case Bytecodes::_i2c: safebits = 0xffff; break;
duke@435:       }
duke@435:       // When casting a masked integer to a smaller signed type, if
duke@435:       // the mask doesn't include the sign bit the cast isn't needed.
duke@435:       if (safebits && (mask & ~safebits) == 0) {
duke@435:         set_canonical(x->value());
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_NullCheck      (NullCheck*       x) {
duke@435:   if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) {
duke@435:     set_canonical(x->obj());
duke@435:   } else {
duke@435:     Constant* con = x->obj()->as_Constant();
duke@435:     if (con) {
duke@435:       ObjectType* c = con->type()->as_ObjectType();
duke@435:       if (c && c->is_loaded()) {
duke@435:         ObjectConstant* oc = c->as_ObjectConstant();
duke@435:         if (!oc || !oc->value()->is_null_object()) {
duke@435:           set_canonical(con);
duke@435:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_Invoke         (Invoke*          x) {}
duke@435: void Canonicalizer::do_NewInstance    (NewInstance*     x) {}
duke@435: void Canonicalizer::do_NewTypeArray   (NewTypeArray*    x) {}
duke@435: void Canonicalizer::do_NewObjectArray (NewObjectArray*  x) {}
duke@435: void Canonicalizer::do_NewMultiArray  (NewMultiArray*   x) {}
duke@435: void Canonicalizer::do_CheckCast      (CheckCast*       x) {
duke@435:   if (x->klass()->is_loaded()) {
duke@435:     Value obj = x->obj();
duke@435:     ciType* klass = obj->exact_type();
duke@435:     if (klass == NULL) klass = obj->declared_type();
duke@435:     if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) {
duke@435:       set_canonical(obj);
duke@435:       return;
duke@435:     }
duke@435:     // checkcast of null returns null
duke@435:     if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
duke@435:       set_canonical(obj);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: void Canonicalizer::do_InstanceOf     (InstanceOf*      x) {
duke@435:   if (x->klass()->is_loaded()) {
duke@435:     Value obj = x->obj();
duke@435:     ciType* exact = obj->exact_type();
duke@435:     if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) {
duke@435:       set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0);
duke@435:       return;
duke@435:     }
duke@435:     // instanceof null returns false
duke@435:     if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
duke@435:       set_constant(0);
duke@435:     }
duke@435:   }
duke@435: 
duke@435: }
duke@435: void Canonicalizer::do_MonitorEnter   (MonitorEnter*    x) {}
duke@435: void Canonicalizer::do_MonitorExit    (MonitorExit*     x) {}
duke@435: void Canonicalizer::do_BlockBegin     (BlockBegin*      x) {}
duke@435: void Canonicalizer::do_Goto           (Goto*            x) {}
duke@435: 
duke@435: 
duke@435: static bool is_true(jlong x, If::Condition cond, jlong y) {
duke@435:   switch (cond) {
duke@435:     case If::eql: return x == y;
duke@435:     case If::neq: return x != y;
duke@435:     case If::lss: return x <  y;
duke@435:     case If::leq: return x <= y;
duke@435:     case If::gtr: return x >  y;
duke@435:     case If::geq: return x >= y;
duke@435:   }
duke@435:   ShouldNotReachHere();
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_If(If* x) {
duke@435:   // move const to right
duke@435:   if (x->x()->type()->is_constant()) x->swap_operands();
duke@435:   // simplify
duke@435:   const Value l = x->x(); ValueType* lt = l->type();
duke@435:   const Value r = x->y(); ValueType* rt = r->type();
duke@435: 
duke@435:   if (l == r && !lt->is_float_kind()) {
duke@435:     // pattern: If (a cond a) => simplify to Goto
duke@435:     BlockBegin* sux;
duke@435:     switch (x->cond()) {
duke@435:     case If::eql: sux = x->sux_for(true);  break;
duke@435:     case If::neq: sux = x->sux_for(false); break;
duke@435:     case If::lss: sux = x->sux_for(false); break;
duke@435:     case If::leq: sux = x->sux_for(true);  break;
duke@435:     case If::gtr: sux = x->sux_for(false); break;
duke@435:     case If::geq: sux = x->sux_for(true);  break;
duke@435:     }
duke@435:     // If is a safepoint then the debug information should come from the state_before of the If.
duke@435:     set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   if (lt->is_constant() && rt->is_constant()) {
duke@435:     if (x->x()->as_Constant() != NULL) {
duke@435:       // pattern: If (lc cond rc) => simplify to: Goto
duke@435:       BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(),
duke@435:                                                        x->sux_for(true),
duke@435:                                                        x->sux_for(false));
duke@435:       if (sux != NULL) {
duke@435:         // If is a safepoint then the debug information should come from the state_before of the If.
duke@435:         set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
duke@435:       }
duke@435:     }
duke@435:   } else if (rt->as_IntConstant() != NULL) {
duke@435:     // pattern: If (l cond rc) => investigate further
duke@435:     const jint rc = rt->as_IntConstant()->value();
duke@435:     if (l->as_CompareOp() != NULL) {
duke@435:       // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto
duke@435:       CompareOp* cmp = l->as_CompareOp();
duke@435:       bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl;
duke@435:       BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b
duke@435:       BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b
duke@435:       BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b
duke@435:       BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered
duke@435:       // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are
duke@435:       //       equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either
duke@435:       //       lss_sux or gtr_sux.
duke@435:       if (lss_sux == eql_sux && eql_sux == gtr_sux) {
duke@435:         // all successors identical => simplify to: Goto
duke@435:         set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint()));
duke@435:       } else {
duke@435:         // two successors differ and two successors are the same => simplify to: If (x cmp y)
duke@435:         // determine new condition & successors
duke@435:         If::Condition cond;
duke@435:         BlockBegin* tsux = NULL;
duke@435:         BlockBegin* fsux = NULL;
duke@435:              if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; }
duke@435:         else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; }
duke@435:         else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; }
duke@435:         else                         { ShouldNotReachHere();                           }
iveresov@2138:         If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint());
duke@435:         if (cmp->x() == cmp->y()) {
duke@435:           do_If(canon);
duke@435:         } else {
iveresov@2138:           if (compilation()->profile_branches()) {
iveresov@2138:             // TODO: If profiling, leave floating point comparisons unoptimized.
iveresov@2138:             // We currently do not support profiling of the unordered case.
iveresov@2138:             switch(cmp->op()) {
iveresov@2138:               case Bytecodes::_fcmpl: case Bytecodes::_fcmpg:
iveresov@2138:               case Bytecodes::_dcmpl: case Bytecodes::_dcmpg:
iveresov@2138:                 set_canonical(x);
iveresov@2138:                 return;
iveresov@2138:             }
iveresov@2138:           }
duke@435:           set_canonical(canon);
duke@435:           set_bci(cmp->bci());
duke@435:         }
duke@435:       }
duke@435:     } else if (l->as_InstanceOf() != NULL) {
duke@435:       // NOTE: Code permanently disabled for now since it leaves the old InstanceOf
duke@435:       //       instruction in the graph (it is pinned). Need to fix this at some point.
iveresov@2146:       //       It should also be left in the graph when generating a profiled method version or Goto
iveresov@2146:       //       has to know that it was an InstanceOf.
duke@435:       return;
duke@435:       // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto
duke@435:       InstanceOf* inst = l->as_InstanceOf();
duke@435:       BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1
duke@435:       BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0
duke@435:       if (is_inst_sux == no_inst_sux && inst->is_loaded()) {
duke@435:         // both successors identical and klass is loaded => simplify to: Goto
duke@435:         set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint()));
duke@435:       } else {
duke@435:         // successors differ => simplify to: IfInstanceOf
duke@435:         set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->bci(), is_inst_sux, no_inst_sux));
duke@435:       }
duke@435:     }
duke@435:   } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) {
duke@435:     if (x->cond() == Instruction::eql) {
duke@435:       set_canonical(new Goto(x->fsux(), x->state_before(), x->is_safepoint()));
duke@435:     } else {
duke@435:       assert(x->cond() == Instruction::neq, "only other valid case");
duke@435:       set_canonical(new Goto(x->tsux(), x->state_before(), x->is_safepoint()));
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_TableSwitch(TableSwitch* x) {
duke@435:   if (x->tag()->type()->is_constant()) {
duke@435:     int v = x->tag()->type()->as_IntConstant()->value();
duke@435:     BlockBegin* sux = x->default_sux();
duke@435:     if (v >= x->lo_key() && v <= x->hi_key()) {
duke@435:       sux = x->sux_at(v - x->lo_key());
duke@435:     }
duke@435:     set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
duke@435:   } else if (x->number_of_sux() == 1) {
duke@435:     // NOTE: Code permanently disabled for now since the switch statement's
duke@435:     //       tag expression may produce side-effects in which case it must
duke@435:     //       be executed.
duke@435:     return;
duke@435:     // simplify to Goto
duke@435:     set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
duke@435:   } else if (x->number_of_sux() == 2) {
duke@435:     // NOTE: Code permanently disabled for now since it produces two new nodes
duke@435:     //       (Constant & If) and the Canonicalizer cannot return them correctly
duke@435:     //       yet. For now we copied the corresponding code directly into the
duke@435:     //       GraphBuilder (i.e., we should never reach here).
duke@435:     return;
duke@435:     // simplify to If
duke@435:     assert(x->lo_key() == x->hi_key(), "keys must be the same");
duke@435:     Constant* key = new Constant(new IntConstant(x->lo_key()));
duke@435:     set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_LookupSwitch(LookupSwitch* x) {
duke@435:   if (x->tag()->type()->is_constant()) {
duke@435:     int v = x->tag()->type()->as_IntConstant()->value();
duke@435:     BlockBegin* sux = x->default_sux();
duke@435:     for (int i = 0; i < x->length(); i++) {
duke@435:       if (v == x->key_at(i)) {
duke@435:         sux = x->sux_at(i);
duke@435:       }
duke@435:     }
duke@435:     set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
duke@435:   } else if (x->number_of_sux() == 1) {
duke@435:     // NOTE: Code permanently disabled for now since the switch statement's
duke@435:     //       tag expression may produce side-effects in which case it must
duke@435:     //       be executed.
duke@435:     return;
duke@435:     // simplify to Goto
duke@435:     set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
duke@435:   } else if (x->number_of_sux() == 2) {
duke@435:     // NOTE: Code permanently disabled for now since it produces two new nodes
duke@435:     //       (Constant & If) and the Canonicalizer cannot return them correctly
duke@435:     //       yet. For now we copied the corresponding code directly into the
duke@435:     //       GraphBuilder (i.e., we should never reach here).
duke@435:     return;
duke@435:     // simplify to If
duke@435:     assert(x->length() == 1, "length must be the same");
duke@435:     Constant* key = new Constant(new IntConstant(x->key_at(0)));
duke@435:     set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_Return         (Return*          x) {}
duke@435: void Canonicalizer::do_Throw          (Throw*           x) {}
duke@435: void Canonicalizer::do_Base           (Base*            x) {}
duke@435: void Canonicalizer::do_OsrEntry       (OsrEntry*        x) {}
duke@435: void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {}
duke@435: 
duke@435: static bool match_index_and_scale(Instruction*  instr,
duke@435:                                   Instruction** index,
duke@435:                                   int*          log2_scale,
duke@435:                                   Instruction** instr_to_unpin) {
duke@435:   *instr_to_unpin = NULL;
duke@435: 
duke@435:   // Skip conversion ops
duke@435:   Convert* convert = instr->as_Convert();
duke@435:   if (convert != NULL) {
duke@435:     instr = convert->value();
duke@435:   }
duke@435: 
duke@435:   ShiftOp* shift = instr->as_ShiftOp();
duke@435:   if (shift != NULL) {
duke@435:     if (shift->is_pinned()) {
duke@435:       *instr_to_unpin = shift;
duke@435:     }
duke@435:     // Constant shift value?
duke@435:     Constant* con = shift->y()->as_Constant();
duke@435:     if (con == NULL) return false;
duke@435:     // Well-known type and value?
duke@435:     IntConstant* val = con->type()->as_IntConstant();
duke@435:     if (val == NULL) return false;
duke@435:     if (shift->x()->type() != intType) return false;
duke@435:     *index = shift->x();
duke@435:     int tmp_scale = val->value();
duke@435:     if (tmp_scale >= 0 && tmp_scale < 4) {
duke@435:       *log2_scale = tmp_scale;
duke@435:       return true;
duke@435:     } else {
duke@435:       return false;
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   ArithmeticOp* arith = instr->as_ArithmeticOp();
duke@435:   if (arith != NULL) {
duke@435:     if (arith->is_pinned()) {
duke@435:       *instr_to_unpin = arith;
duke@435:     }
duke@435:     // Check for integer multiply
duke@435:     if (arith->op() == Bytecodes::_imul) {
duke@435:       // See if either arg is a known constant
duke@435:       Constant* con = arith->x()->as_Constant();
duke@435:       if (con != NULL) {
duke@435:         *index = arith->y();
duke@435:       } else {
duke@435:         con = arith->y()->as_Constant();
duke@435:         if (con == NULL) return false;
duke@435:         *index = arith->x();
duke@435:       }
duke@435:       if ((*index)->type() != intType) return false;
duke@435:       // Well-known type and value?
duke@435:       IntConstant* val = con->type()->as_IntConstant();
duke@435:       if (val == NULL) return false;
duke@435:       switch (val->value()) {
duke@435:       case 1: *log2_scale = 0; return true;
duke@435:       case 2: *log2_scale = 1; return true;
duke@435:       case 4: *log2_scale = 2; return true;
duke@435:       case 8: *log2_scale = 3; return true;
duke@435:       default:            return false;
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Unknown instruction sequence; don't touch it
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: 
duke@435: static bool match(UnsafeRawOp* x,
duke@435:                   Instruction** base,
duke@435:                   Instruction** index,
duke@435:                   int*          log2_scale) {
duke@435:   Instruction* instr_to_unpin = NULL;
duke@435:   ArithmeticOp* root = x->base()->as_ArithmeticOp();
duke@435:   if (root == NULL) return false;
duke@435:   // Limit ourselves to addition for now
duke@435:   if (root->op() != Bytecodes::_ladd) return false;
duke@435:   // Try to find shift or scale op
duke@435:   if (match_index_and_scale(root->y(), index, log2_scale, &instr_to_unpin)) {
duke@435:     *base = root->x();
duke@435:   } else if (match_index_and_scale(root->x(), index, log2_scale, &instr_to_unpin)) {
duke@435:     *base = root->y();
duke@435:   } else if (root->y()->as_Convert() != NULL) {
duke@435:     Convert* convert = root->y()->as_Convert();
duke@435:     if (convert->op() == Bytecodes::_i2l && convert->value()->type() == intType) {
duke@435:       // pick base and index, setting scale at 1
duke@435:       *base  = root->x();
duke@435:       *index = convert->value();
duke@435:       *log2_scale = 0;
duke@435:     } else {
duke@435:       return false;
duke@435:     }
duke@435:   } else {
duke@435:     // doesn't match any expected sequences
duke@435:     return false;
duke@435:   }
duke@435: 
duke@435:   // If the value is pinned then it will be always be computed so
duke@435:   // there's no profit to reshaping the expression.
duke@435:   return !root->is_pinned();
duke@435: }
duke@435: 
duke@435: 
duke@435: void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) {
duke@435:   Instruction* base = NULL;
duke@435:   Instruction* index = NULL;
duke@435:   int          log2_scale;
duke@435: 
duke@435:   if (match(x, &base, &index, &log2_scale)) {
duke@435:     x->set_base(base);
duke@435:     x->set_index(index);
duke@435:     x->set_log2_scale(log2_scale);
duke@435:     if (PrintUnsafeOptimization) {
duke@435:       tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d",
duke@435:                     x->id(), x->base()->id(), x->index()->id(), x->log2_scale());
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void Canonicalizer::do_RoundFP(RoundFP* x) {}
duke@435: void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
duke@435: void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
duke@435: void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {}
duke@435: void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {}
duke@435: void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead*  x) {}
duke@435: void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {}
duke@435: void Canonicalizer::do_ProfileCall(ProfileCall* x) {}
iveresov@2138: void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {}
iveresov@2138: