Mercurial > hg > graal-compiler
view src/share/vm/c1/c1_Canonicalizer.cpp @ 7172:bbc14465e7db
8003689: MemTracker::init_tracking_options() reads outside array if commandline argument is empty
Summary: Fixed potential buffer overrun when giving empty option to NativeMemoryTracking commandline option
Reviewed-by: ctornqvi, hseigel, kvn
author | zgu |
---|---|
date | Wed, 28 Nov 2012 09:19:38 -0500 |
parents | b9a9ed0f8eeb |
children | 46f6f063b272 |
line wrap: on
line source
/* * Copyright (c) 1999, 2012, 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_ProfileInvoke(ProfileInvoke* x) {} void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {} void Canonicalizer::do_MemBar(MemBar* x) {}