jdk8-mips64-public/hotspot: src/share/vm/c1/c1_Canonicalizer.cpp@710a3c8b516e (annotated)

src/share/vm/c1/c1_Canonicalizer.cpp@710a3c8b516e (annotated)

src/share/vm/c1/c1_Canonicalizer.cpp

Tue, 08 Aug 2017 15:57:29 +0800

author: aoqi
date: Tue, 08 Aug 2017 15:57:29 +0800
changeset 6876: 710a3c8b516e
parent 6198: 55fb97c4c58d
parent 0: f90c822e73f8
child 7535: 7ae4e26cb1e0
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "c1/c1_Canonicalizer.hpp"
 #include "c1/c1_InstructionPrinter.hpp"
 #include "c1/c1_ValueStack.hpp"
 #include "ci/ciArray.hpp"
 #include "runtime/sharedRuntime.hpp"
 class PrintValueVisitor: public ValueVisitor {
   void visit(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) {
 #ifndef PRODUCT
     if (!x->has_printable_bci()) {
       x->set_printable_bci(bci());
     }
 #endif
     if (PrintCanonicalization) {
       PrintValueVisitor do_print_value;
       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->state_before(), x->needs_patching()));
       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) {
       ciField* field = lf->field();
       if (field->is_constant() && field->is_static()) {
         // final static field
         ciObject* c = 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->state_before()));
       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;
   }
   case vmIntrinsics::_isInstance          : {
     assert(x->number_of_arguments() == 2, "wrong type");
     InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
     if (c != NULL && !c->value()->is_null_object()) {
       // ciInstance::java_mirror_type() returns non-NULL only for Java mirrors
       ciType* t = c->value()->as_instance()->java_mirror_type();
       if (t->is_klass()) {
         // substitute cls.isInstance(obj) of a constant Class into
         // an InstantOf instruction
         InstanceOf* i = new InstanceOf(t->as_klass(), x->argument_at(1), x->state_before());
         set_canonical(i);
         // and try to canonicalize even further
         do_InstanceOf(i);
       } else {
         assert(t->is_primitive_type(), "should be a primitive type");
         // cls.isInstance(obj) always returns false for primitive classes
         set_constant(0);
       }
     }
     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_TypeCast       (TypeCast*        x) {}
 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;
 }
 static bool is_safepoint(BlockEnd* x, BlockBegin* sux) {
   // An Instruction with multiple successors, x, is replaced by a Goto
   // to a single successor, sux. Is a safepoint check needed = was the
   // instruction being replaced a safepoint and the single remaining
   // successor a back branch?
   return x->is_safepoint() && (sux->bci() < x->state_before()->bci());
 }
 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(), is_safepoint(x, sux)));
     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(), is_safepoint(x, sux)));
       }
     }
   } 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 {
           if (compilation()->profile_branches()) {
             // TODO: If profiling, leave floating point comparisons unoptimized.
             // We currently do not support profiling of the unordered case.
             switch(cmp->op()) {
               case Bytecodes::_fcmpl: case Bytecodes::_fcmpg:
               case Bytecodes::_dcmpl: case Bytecodes::_dcmpg:
                 set_canonical(x);
                 return;
             }
           }
           set_bci(cmp->state_before()->bci());
           set_canonical(canon);
         }
       }
     } 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.
       //       It should also be left in the graph when generating a profiled method version or Goto
       //       has to know that it was an InstanceOf.
       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->state_before()->bci(), is_inst_sux, no_inst_sux));
       }
     }
   } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) {
     if (x->cond() == Instruction::eql) {
       BlockBegin* sux = x->fsux();
       set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
     } else {
       assert(x->cond() == Instruction::neq, "only other valid case");
       BlockBegin* sux = x->tsux();
       set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
     }
   }
 }
 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(), is_safepoint(x, sux)));
   } 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(), is_safepoint(x, sux)));
   } 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_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) {}
 void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead*  x) {}
 void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {}
 void Canonicalizer::do_ProfileCall(ProfileCall* x) {}
 void Canonicalizer::do_ProfileReturnType(ProfileReturnType* x) {}
 void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {}
 void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {}
 void Canonicalizer::do_RangeCheckPredicate(RangeCheckPredicate* x) {}
 #ifdef ASSERT
 void Canonicalizer::do_Assert(Assert* x) {}
 #endif
 void Canonicalizer::do_MemBar(MemBar* x) {}

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/c1/c1_Canonicalizer.cpp@710a3c8b516e (annotated)

src/share/vm/c1/c1_Canonicalizer.cpp