--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/c1/c1_Canonicalizer.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1055 @@
+/*
+ * Copyright (c) 1999, 2017, 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;
+ default : break;
+ }
+ }
+
+ 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;
+ default : break;
+ }
+ }
+ 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;
+ default : break;
+ }
+ }
+ break;
+ default:
+ // other cases not implemented (must be extremely careful with floats & doubles!)
+ break;
+ }
+ }
+ // 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;
+ default : break;
+ }
+ }
+ 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;
+ default : break;
+ }
+ }
+ break;
+ default:
+ 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;
+ default : 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* na;
+ Constant* ct;
+ LoadField* lf;
+
+ if ((na = x->array()->as_NewArray()) != NULL) {
+ // New arrays might have the known length.
+ // 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.
+ Constant* length;
+ if (na->length() != NULL &&
+ (length = na->length()->as_Constant()) != NULL) {
+ assert(length->type()->as_IntConstant() != NULL, "array length must be integer");
+ set_constant(length->type()->as_IntConstant()->value());
+ }
+
+ } else if ((ct = x->array()->as_Constant()) != NULL) {
+ // Constant arrays have constant lengths.
+ ArrayConstant* cnst = ct->type()->as_ArrayConstant();
+ if (cnst != NULL) {
+ set_constant(cnst->value()->length());
+ }
+
+ } else if ((lf = x->array()->as_LoadField()) != NULL) {
+ ciField* field = lf->field();
+ if (field->is_static_constant()) {
+ // Constant field loads are usually folded during parsing.
+ // But it doesn't happen with PatchALot, ScavengeRootsInCode < 2, or when
+ // holder class is being initialized during parsing (for static fields).
+ ciObject* c = field->constant_value().as_object();
+ if (!c->is_null_object()) {
+ set_constant(c->as_array()->length());
+ }
+ }
+ }
+}
+
+void Canonicalizer::do_LoadIndexed (LoadIndexed* x) {
+ StableArrayConstant* array = x->array()->type()->as_StableArrayConstant();
+ IntConstant* index = x->index()->type()->as_IntConstant();
+
+ assert(array == NULL || FoldStableValues, "not enabled");
+
+ // Constant fold loads from stable arrays.
+ if (!x->mismatched() && array != NULL && index != NULL) {
+ jint idx = index->value();
+ if (idx < 0 || idx >= array->value()->length()) {
+ // Leave the load as is. The range check will handle it.
+ return;
+ }
+
+ ciConstant field_val = array->value()->element_value(idx);
+ if (!field_val.is_null_or_zero()) {
+ jint dimension = array->dimension();
+ assert(dimension <= array->value()->array_type()->dimension(), "inconsistent info");
+ ValueType* value = NULL;
+ if (dimension > 1) {
+ // Preserve information about the dimension for the element.
+ assert(field_val.as_object()->is_array(), "not an array");
+ value = new StableArrayConstant(field_val.as_object()->as_array(), dimension - 1);
+ } else {
+ assert(dimension == 1, "sanity");
+ value = as_ValueType(field_val);
+ }
+ set_canonical(new Constant(value));
+ }
+ }
+}
+
+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;
+ default : 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(),
+ x->check_boolean()));
+ 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;
+ default: break;
+ }
+ } 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;
+ default: break;
+ }
+ }
+ }
+ }
+ 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_LongConstant()->value() == (jlong)0) set_canonical(x->x()); return;
+ default : ShouldNotReachHere(); return;
+ }
+ }
+}
+
+
+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;
+ }
+ default:
+ 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;
+ }
+
+ default:
+ 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()->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;
+ }
+ case vmIntrinsics::_isPrimitive : {
+ assert(x->number_of_arguments() == 1, "wrong type");
+
+ // Class.isPrimitive is known on constant classes:
+ InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
+ if (c != NULL && !c->value()->is_null_object()) {
+ ciType* t = c->value()->java_mirror_type();
+ set_constant(t->is_primitive_type());
+ }
+ break;
+ }
+ default:
+ 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;
+ default : 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;
+ default : 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;
+ default : 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;
+ default:
+ 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 = NULL;
+ 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;
+ default: ShouldNotReachHere();
+ }
+ // 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 = If::eql;
+ 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;
+ default:
+ break;
+ }
+ }
+ 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() ||
+ (l->as_Local() && l->as_Local()->is_receiver()))) {
+ 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) {
+ // Skip conversion ops. This works only on 32bit because of the implicit l2i that the
+ // unsafe performs.
+#ifndef _LP64
+ Convert* convert = instr->as_Convert();
+ if (convert != NULL && convert->op() == Bytecodes::_i2l) {
+ assert(convert->value()->type() == intType, "invalid input type");
+ instr = convert->value();
+ }
+#endif
+
+ ShiftOp* shift = instr->as_ShiftOp();
+ if (shift != NULL) {
+ if (shift->op() == Bytecodes::_lshl) {
+ assert(shift->x()->type() == longType, "invalid input type");
+ } else {
+#ifndef _LP64
+ if (shift->op() == Bytecodes::_ishl) {
+ assert(shift->x()->type() == intType, "invalid input type");
+ } else {
+ return false;
+ }
+#else
+ return false;
+#endif
+ }
+
+
+ // 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();
+ assert(val != NULL, "Should be an int constant");
+
+ *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) {
+ // 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();
+ }
+ long const_value;
+ // Check for integer multiply
+ if (arith->op() == Bytecodes::_lmul) {
+ assert((*index)->type() == longType, "invalid input type");
+ LongConstant* val = con->type()->as_LongConstant();
+ assert(val != NULL, "expecting a long constant");
+ const_value = val->value();
+ } else {
+#ifndef _LP64
+ if (arith->op() == Bytecodes::_imul) {
+ assert((*index)->type() == intType, "invalid input type");
+ IntConstant* val = con->type()->as_IntConstant();
+ assert(val != NULL, "expecting an int constant");
+ const_value = val->value();
+ } else {
+ return false;
+ }
+#else
+ return false;
+#endif
+ }
+ switch (const_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) {
+ ArithmeticOp* root = x->base()->as_ArithmeticOp();
+ if (root == NULL) return false;
+ // Limit ourselves to addition for now
+ if (root->op() != Bytecodes::_ladd) return false;
+
+ bool match_found = false;
+ // Try to find shift or scale op
+ if (match_index_and_scale(root->y(), index, log2_scale)) {
+ *base = root->x();
+ match_found = true;
+ } else if (match_index_and_scale(root->x(), index, log2_scale)) {
+ *base = root->y();
+ match_found = true;
+ } else if (NOT_LP64(root->y()->as_Convert() != NULL) LP64_ONLY(false)) {
+ // Skipping i2l works only on 32bit because of the implicit l2i that the unsafe performs.
+ // 64bit needs a real sign-extending conversion.
+ Convert* convert = root->y()->as_Convert();
+ if (convert->op() == Bytecodes::_i2l) {
+ assert(convert->value()->type() == intType, "should be an int");
+ // pick base and index, setting scale at 1
+ *base = root->x();
+ *index = convert->value();
+ *log2_scale = 0;
+ match_found = true;
+ }
+ }
+ // The default solution
+ if (!match_found) {
+ *base = root->x();
+ *index = root->y();
+ *log2_scale = 0;
+ }
+
+ // 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_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) {}