Deoptimization support in inlined code.

runtime/vm/flow_graph_allocator.cc

Index: runtime/vm/flow_graph_allocator.cc
diff --git a/runtime/vm/flow_graph_allocator.cc b/runtime/vm/flow_graph_allocator.cc
index 2118c08fb44d5cee13d1d9f4921779269795ed71..d01dcce64b76eaf67b3df11ba31d35fbbe750cfc 100644
--- a/runtime/vm/flow_graph_allocator.cc
+++ b/runtime/vm/flow_graph_allocator.cc
@@ -149,8 +149,10 @@ void FlowGraphAllocator::ComputeInitialSets() {
       // Add non-argument uses from the deoptimization environment (pushed
       // arguments are not allocated by the register allocator).
       if (current->env() != NULL) {
-        for (intptr_t i = 0; i < current->env()->Length(); ++i) {
-          Value* value = current->env()->ValueAt(i);
+        for (Environment::DeepIterator env_it(current->env());
+             !env_it.Done();
+             env_it.Advance()) {
+          Value* value = env_it.CurrentValue();
           if (!value->definition()->IsPushArgument()) {
             live_in->Add(value->definition()->ssa_temp_index());
           }
@@ -735,11 +737,14 @@ void FlowGraphAllocator::ConnectIncomingPhiMoves(BlockEntryInstr* block) {
 }
 
 
-void FlowGraphAllocator::ProcessEnvironmentUses(BlockEntryInstr* block,
-                                                Instruction* current) {
-  ASSERT(current->env() != NULL);
+void FlowGraphAllocator::ProcessEnvironmentUsesRecursive(BlockEntryInstr* block,
+                                                         Instruction* current,
+                                                         Environment* env) {
+  if (env == NULL) return;
 
-  Environment* env = current->env();
+  if (env->outer() != NULL) {

[Kevin Millikin (Google), 2012/09/18 11:01:55]

The base of the recursion handles env == NULL, so no need to test (or: you can
assert env is not NULL instead of checking for NULL an returning).

It is probably better to turn this into a while loop, since it doesn't seem to
matter which order we process the environments.

[zerny-google, 2012/09/18 11:53:07]

Done.

+    ProcessEnvironmentUsesRecursive(block, current, env->outer());
+  }
 
   // Any value mentioned in the deoptimization environment should survive
   // until the end of instruction but it does not need to be in the register.
@@ -784,6 +789,13 @@ void FlowGraphAllocator::ProcessEnvironmentUses(BlockEntryInstr* block,
 }
 
 
+void FlowGraphAllocator::ProcessEnvironmentUses(BlockEntryInstr* block,
+                                                Instruction* current) {
+  ASSERT(current->env() != NULL);
+  ProcessEnvironmentUsesRecursive(block, current, current->env());
+}
+
+
 // Create and update live ranges corresponding to instruction's inputs,
 // temporaries and output.
 void FlowGraphAllocator::ProcessOneInstruction(BlockEntryInstr* block,