ARM: Track Smis on top 4 stack positions and Smi loop variables....

src/arm/jump-target-arm.cc

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 32 matching lines @@
 #define __ ACCESS_MASM(cgen()->masm())
 
 void JumpTarget::DoJump() {
   ASSERT(cgen()->has_valid_frame());
   // Live non-frame registers are not allowed at unconditional jumps
   // because we have no way of invalidating the corresponding results
   // which are still live in the C++ code.
   ASSERT(cgen()->HasValidEntryRegisters());
 
   if (entry_frame_set_) {
+    if (entry_label_.is_bound()) {
+      // If we already bound and generated code at the destination then it
+      // is too late to ask for less optimistic type assumptions.
+      ASSERT(entry_frame_.IsCompatibleWith(cgen()->frame()));
+    }
     // There already a frame expectation at the target.
     cgen()->frame()->MergeTo(&entry_frame_);
     cgen()->DeleteFrame();
   } else {
     // Clone the current frame to use as the expected one at the target.
     set_entry_frame(cgen()->frame());
     RegisterFile empty;
     cgen()->SetFrame(NULL, &empty);
   }
   __ jmp(&entry_label_);
 }
 
 
 void JumpTarget::DoBranch(Condition cc, Hint ignored) {
   ASSERT(cgen()->has_valid_frame());
 
   if (entry_frame_set_) {
-    // Backward branch.  We have an expected frame to merge to on the
-    // backward edge.
+    if (entry_label_.is_bound()) {
+      // If we already bound and generated code at the destination then it
+      // is too late to ask for less optimistic type assumptions.
+      ASSERT(entry_frame_.IsCompatibleWith(cgen()->frame()));
+    }
+    // We have an expected frame to merge to on the backward edge.
     cgen()->frame()->MergeTo(&entry_frame_, cc);
   } else {
     // Clone the current frame to use as the expected one at the target.
     set_entry_frame(cgen()->frame());
   }
   __ b(cc, &entry_label_);
   if (cc == al) {
     cgen()->DeleteFrame();
   }
 }
@@ skipping 48 matching lines @@
   __ bind(&entry_label_);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM