Add new relocation type WASM_MEMORY_SIZE_REFERENCE, use relocatable pointers to update wasm memory …

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 366 matching lines @@
 
   // The maximum pc delta that will use the short encoding.
   static const int kMaxSmallPCDelta;
 
   enum Mode {
     // Please note the order is important (see IsCodeTarget, IsGCRelocMode).
     CODE_TARGET,  // Code target which is not any of the above.
     CODE_TARGET_WITH_ID,
     DEBUGGER_STATEMENT,  // Code target for the debugger statement.
     EMBEDDED_OBJECT,
-    CELL,
     // To relocate pointers into the wasm memory embedded in wasm code
     WASM_MEMORY_REFERENCE,
+    WASM_MEMORY_SIZE_REFERENCE,

[gdeepti, 2016/04/26 08:09:36]

Removing wasm RelocInfo modes from the shareable relocation modes list for now
as this causes multiple updates to the same constants in the constant pool in
some cases on Arm, fix in progress. 

+    CELL,
 
     // Everything after runtime_entry (inclusive) is not GC'ed.
     RUNTIME_ENTRY,
     COMMENT,
     POSITION,            // See comment for kNoPosition above.
     STATEMENT_POSITION,  // See comment for kNoPosition above.
 
     // Additional code inserted for debug break slot.
     DEBUG_BREAK_SLOT_AT_POSITION,
     DEBUG_BREAK_SLOT_AT_RETURN,
@@ skipping 23 matching lines @@
     // Pseudo-types
     NUMBER_OF_MODES,
     NONE32,             // never recorded 32-bit value
     NONE64,             // never recorded 64-bit value
     CODE_AGE_SEQUENCE,  // Not stored in RelocInfo array, used explictly by
                         // code aging.
 
     FIRST_REAL_RELOC_MODE = CODE_TARGET,
     LAST_REAL_RELOC_MODE = VENEER_POOL,
     LAST_CODE_ENUM = DEBUGGER_STATEMENT,
-    LAST_GCED_ENUM = WASM_MEMORY_REFERENCE,
+    LAST_GCED_ENUM = WASM_MEMORY_SIZE_REFERENCE,
     FIRST_SHAREABLE_RELOC_MODE = CELL,
   };
 
   STATIC_ASSERT(NUMBER_OF_MODES <= kBitsPerInt);
 
   explicit RelocInfo(Isolate* isolate) : isolate_(isolate) {
     DCHECK_NOT_NULL(isolate);
   }
 
   RelocInfo(Isolate* isolate, byte* pc, Mode rmode, intptr_t data, Code* host)
@@ skipping 70 matching lines @@
   }
   static inline bool IsCodeAgeSequence(Mode mode) {
     return mode == CODE_AGE_SEQUENCE;
   }
   static inline bool IsGeneratorContinuation(Mode mode) {
     return mode == GENERATOR_CONTINUATION;
   }
   static inline bool IsWasmMemoryReference(Mode mode) {
     return mode == WASM_MEMORY_REFERENCE;
   }
+  static inline bool IsWasmMemorySizeReference(Mode mode) {
+    return mode == WASM_MEMORY_SIZE_REFERENCE;
+  }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors
   Isolate* isolate() const { return isolate_; }
   byte* pc() const { return pc_; }
   void set_pc(byte* pc) { pc_ = pc; }
   Mode rmode() const {  return rmode_; }
   intptr_t data() const { return data_; }
   Code* host() const { return host_; }
   void set_host(Code* host) { host_ = host; }
@@ skipping 41 matching lines @@
                                   UPDATE_WRITE_BARRIER,
                               ICacheFlushMode icache_flush_mode =
                                   FLUSH_ICACHE_IF_NEEDED));
   INLINE(Handle<Object> code_age_stub_handle(Assembler* origin));
   INLINE(Code* code_age_stub());
   INLINE(void set_code_age_stub(Code* stub,
                                 ICacheFlushMode icache_flush_mode =
                                     FLUSH_ICACHE_IF_NEEDED));
 
   INLINE(Address wasm_memory_reference());
+  INLINE(int32_t wasm_memory_size_reference());
   INLINE(void update_wasm_memory_reference(
-      Address old_base, Address new_base, size_t old_size, size_t new_size,
+      Address old_base, Address new_base, int32_t old_size, int32_t new_size,
       ICacheFlushMode icache_flush_mode = SKIP_ICACHE_FLUSH));
   // Returns the address of the constant pool entry where the target address
   // is held.  This should only be called if IsInConstantPool returns true.
   INLINE(Address constant_pool_entry_address());
 
   // Read the address of the word containing the target_address in an
   // instruction stream.  What this means exactly is architecture-independent.
   // The only architecture-independent user of this function is the serializer.
   // The serializer uses it to find out how many raw bytes of instruction to
   // output before the next target.  Architecture-independent code shouldn't
@@ skipping 729 matching lines @@
     std::vector<ConstantPoolEntry> shared_entries;
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_ASSEMBLER_H_