Fix a few comments in vectorization code that were incorrect or incomplete.

Test: test-art-target
Change-Id: I7c6a5a2d29edd0b2782abc303d8d8cb09c1c2f91

1 files changed, 6 insertions, 4 deletions

diff --git a/compiler/optimizing/loop_optimization.cc b/compiler/optimizing/loop_optimization.cc
index ca31bf89e6..1a79601a93 100644
--- a/compiler/optimizing/loop_optimization.cc
+++ b/compiler/optimizing/loop_optimization.cc
@@ -544,12 +544,13 @@ void HLoopOptimization::GenerateNewLoop(LoopNode* node,
     bool vectorized_def = VectorizeDef(node, it.Current(), /*generate_code*/ true);
     DCHECK(vectorized_def);
   }
-  // Generate body.
+  // Generate body from the instruction map, but in original program order.
   HEnvironment* env = vector_header_->GetFirstInstruction()->GetEnvironment();
   for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
     auto i = vector_map_->find(it.Current());
     if (i != vector_map_->end() && !i->second->IsInBlock()) {
-      Insert(vector_body_, i->second);  // lays out in original order
+      Insert(vector_body_, i->second);
+      // Deal with instructions that need an environment, such as the scalar intrinsics.
       if (i->second->NeedsEnvironment()) {
         i->second->CopyEnvironmentFromWithLoopPhiAdjustment(env, vector_header_);
       }
@@ -991,8 +992,9 @@ void HLoopOptimization::GenerateVecOp(HInstruction* org,
             UNREACHABLE();
         }  // switch invoke
       } else {
-        // In scalar code, simply clone the method invoke, and replace its operands
-        // with the corresponding new scalar instructions in the loop.
+        // In scalar code, simply clone the method invoke, and replace its operands with the
+        // corresponding new scalar instructions in the loop. The instruction will get an
+        // environment while being inserted from the instruction map in original program order.
         DCHECK(vector_mode_ == kSequential);
         HInvokeStaticOrDirect* new_invoke = new (global_allocator_) HInvokeStaticOrDirect(
             global_allocator_,