Java example source code file (c1_Canonicalizer.cpp)
The c1_Canonicalizer.cpp Java example source code
/*
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* 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.
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*/
#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) {}
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