Version 3.5.6.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index 53ebec239e68b9b98a40103b21574619996dde87..e752b714e4a6040d056fac630b37e809cb2c6201 100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -2237,14 +2237,18 @@ class LChunkBuilder BASE_EMBEDDED {
   template<int I, int T>
       LInstruction* DefineFixedDouble(LTemplateInstruction<1, I, T>* instr,
                                       XMMRegister reg);
+  // Assigns an environment to an instruction.  An instruction which can
+  // deoptimize must have an environment.
   LInstruction* AssignEnvironment(LInstruction* instr);
+  // Assigns a pointer map to an instruction.  An instruction which can
+  // trigger a GC or a lazy deoptimization must have a pointer map.
   LInstruction* AssignPointerMap(LInstruction* instr);
 
   enum CanDeoptimize { CAN_DEOPTIMIZE_EAGERLY, CANNOT_DEOPTIMIZE_EAGERLY };
 
-  // By default we assume that instruction sequences generated for calls
-  // cannot deoptimize eagerly and we do not attach environment to this
-  // instruction.
+  // Marks a call for the register allocator.  Assigns a pointer map to
+  // support GC and lazy deoptimization.  Assigns an environment to support
+  // eager deoptimization if CAN_DEOPTIMIZE_EAGERLY.
   LInstruction* MarkAsCall(
       LInstruction* instr,
       HInstruction* hinstr,