Lattice-based representation inference, powered by left/right specific type feedback for BinaryOps …

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 458639dd897d62e8b0c3c1cc5ea2564784d0485f..f0ee2bf6e5705445370c493b4eeb18f2f7be46f0 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -222,7 +222,30 @@ bool LCodeGen::GenerateBody() {
     }
 
     if (emit_instructions) {
-      Comment(";;; @%d: %s.", current_instruction_, instr->Mnemonic());
+      if (FLAG_code_comments) {
+        HValue* hydrogen = instr->hydrogen_value();
+        if (hydrogen != NULL) {
+          if (hydrogen->IsChange()) {
+            HValue* changed_value = HChange::cast(hydrogen)->value();
+            int use_id = 0;
+            const char* use_mnemo = "dead";
+            if (hydrogen->UseCount() >= 1) {
+              HValue* use_value = hydrogen->uses().value();
+              use_id = use_value->id();
+              use_mnemo = use_value->Mnemonic();
+            }
+            Comment(";;; @%d: %s. <of #%d %s for #%d %s>",
+                    current_instruction_, instr->Mnemonic(),
+                    changed_value->id(), changed_value->Mnemonic(),
+                    use_id, use_mnemo);
+          } else {
+            Comment(";;; @%d: %s. <#%d>", current_instruction_,
+                    instr->Mnemonic(), hydrogen->id());
+          }
+        } else {
+          Comment(";;; @%d: %s.", current_instruction_, instr->Mnemonic());
+        }
+      }
       instr->CompileToNative(this);
     }
   }