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; } }
void InstructionPrinter::do_Constant(Constant* x) { ValueType* t = x->type(); switch (t->tag()) { case intTag : output()->print("%d" , t->as_IntConstant ()->value()); break; case longTag : output()->print(os::jlong_format_specifier(), t->as_LongConstant()->value()); output()->print("L"); break; case floatTag : output()->print("%g" , t->as_FloatConstant ()->value()); break; case doubleTag : output()->print("%gD" , t->as_DoubleConstant()->value()); break; case objectTag : print_object(x); break; case addressTag: output()->print("bci:%d", t->as_AddressConstant()->value()); break; default : output()->print("???"); break; } }
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_ShiftOp (ShiftOp* x) { ValueType* t = x->x()->type(); if (t->is_constant()) { switch (t->tag()) { case intTag : if (t->as_IntConstant()->value() == 0) set_constant(0); return; case longTag : if (t->as_LongConstant()->value() == (jlong)0) set_constant(jlong_cast(0)); return; default : ShouldNotReachHere(); } } ValueType* t2 = x->y()->type(); if (t2->is_constant()) { switch (t2->tag()) { case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; default : ShouldNotReachHere(); } } }
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 (lt->is_constant() && rt->is_constant()) { // pattern: If (lc cond rc) => simplify to: Goto Goto* g = NULL; switch (lt->tag()) { case intTag: g = new Goto(x->sux_for(is_true(lt->as_IntConstant ()->value(), x->cond(), rt->as_IntConstant ()->value())), x->is_safepoint()); break; case longTag: g = new Goto(x->sux_for(is_true(lt->as_LongConstant()->value(), x->cond(), rt->as_LongConstant()->value())), x->is_safepoint()); break; // other cases not implemented (must be extremely careful with floats & doubles!) } if (g != NULL) { // If this If is a safepoint then the debug information should come from the state_before of the If. g->set_state_before(x->state_before()); set_canonical(g); } } 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->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(); } set_canonical(new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint())); set_bci(cmp->bci()); } } 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. 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->is_safepoint())); } else { // successors differ => simplify to: IfInstanceOf set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->bci(), is_inst_sux, no_inst_sux)); } } } }