VM: Make optimized try-catch work in DBC.

runtime/vm/intermediate_language_dbc.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 1101 matching lines @@
 }
 
 
 EMIT_NATIVE_CODE(CatchBlockEntry, 0) {
   __ Bind(compiler->GetJumpLabel(this));
   compiler->AddExceptionHandler(catch_try_index(),
                                 try_index(),
                                 compiler->assembler()->CodeSize(),
                                 catch_handler_types_,
                                 needs_stacktrace());
-  __ MoveSpecial(-exception_var().index()-1,
+
+  if (HasParallelMove()) {
+    compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
+  }
+
+  __ MoveSpecial(LocalVarIndex(0, exception_var().index()),
                  Simulator::kExceptionSpecialIndex);
-  __ MoveSpecial(-stacktrace_var().index()-1,
+  __ MoveSpecial(LocalVarIndex(0, stacktrace_var().index()),
                  Simulator::kStacktraceSpecialIndex);
   __ SetFrame(compiler->StackSize());
 }
 
 
 EMIT_NATIVE_CODE(Throw, 0, Location::NoLocation(), LocationSummary::kCall) {
   __ Throw(0);
   compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
                                  deopt_id(),
                                  token_pos());
@@ skipping 258 matching lines @@
     if (DeoptIfNull()) {
       __ IfEqNull(value);
     } else {
       __ IfNeNull(value);
     }
   } else {
     ASSERT((unary_checks().GetReceiverClassIdAt(0) != kSmiCid) ||
            (unary_checks().NumberOfChecks() > 1));
     const intptr_t may_be_smi =
         (unary_checks().GetReceiverClassIdAt(0) == kSmiCid) ? 1 : 0;
+    bool is_dense_switch = false;
+    intptr_t cid_mask = 0;
     if (IsDenseSwitch()) {
       ASSERT(cids_[0] < cids_[cids_.length() - 1]);
+      cid_mask = ComputeCidMask();
+      is_dense_switch = Smi::IsValid(cid_mask);

[Florian Schneider, 2016/10/04 17:07:57]

I'll fix this in a follow-up CL by adding support for adding untagged immediates
to the constant pool. For now, just bail out to the generic CheckClass if mask
is too large for a smi.

+    }
+    if (is_dense_switch) {
       const intptr_t low_cid = cids_[0];
-      const intptr_t cid_mask = ComputeCidMask();
       __ CheckDenseSwitch(value, may_be_smi);
       __ Nop(compiler->ToEmbeddableCid(low_cid, this));
       __ Nop(__ AddConstant(Smi::Handle(Smi::New(cid_mask))));
     } else {
       GrowableArray<CidTarget> sorted_ic_data;
       FlowGraphCompiler::SortICDataByCount(unary_checks(),
                                            &sorted_ic_data,
                                            /* drop_smi = */ true);
       const intptr_t sorted_length = sorted_ic_data.length();
       if (!Utils::IsUint(8, sorted_length)) {
@@ skipping 466 matching lines @@
   __ IfULe(length, index);
   compiler->EmitDeopt(deopt_id(),
                       ICData::kDeoptCheckArrayBound,
                       (generalized_ ? ICData::kGeneralized : 0) |
                       (licm_hoisted_ ? ICData::kHoisted : 0));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC