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

src/x64/assembler-x64-inl.h

Index: src/x64/assembler-x64-inl.h
diff --git a/src/x64/assembler-x64-inl.h b/src/x64/assembler-x64-inl.h
index 95b3c717747a84adb2accbecb989a800f1fc8122..1e66025ab291b1281a1f6f9cb516512ce43984e1 100644
--- a/src/x64/assembler-x64-inl.h
+++ b/src/x64/assembler-x64-inl.h
@@ -333,6 +333,11 @@ Address RelocInfo::wasm_memory_reference() {
   return Memory::Address_at(pc_);
 }
 
+int32_t RelocInfo::wasm_memory_size_reference() {
+  DCHECK(IsWasmMemorySizeReference(rmode_));
+  return Memory::int32_at(pc_);
+}
+
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
                               || rmode_ == EMBEDDED_OBJECT
@@ -371,15 +376,27 @@ void RelocInfo::set_target_address(Address target,
 }
 
 void RelocInfo::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) {
-  DCHECK(IsWasmMemoryReference(rmode_));
-  DCHECK(old_base <= wasm_memory_reference() &&
-         wasm_memory_reference() < old_base + old_size);
-  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
-  DCHECK(new_base <= updated_reference &&
-         updated_reference < new_base + new_size);
-  Memory::Address_at(pc_) = updated_reference;
+  DCHECK(IsWasmMemoryReference(rmode_) || IsWasmMemorySizeReference(rmode_));
+  if (IsWasmMemoryReference(rmode_)) {
+    Address updated_reference;
+    DCHECK(old_base <= wasm_memory_reference() &&
+           wasm_memory_reference() < old_base + old_size);
+    updated_reference = new_base + (wasm_memory_reference() - old_base);
+    DCHECK(new_base <= updated_reference &&
+           updated_reference < new_base + new_size);
+    Memory::Address_at(pc_) = updated_reference;
+  } else if (IsWasmMemorySizeReference(rmode_)) {
+    int32_t updated_size_reference;
+    DCHECK(wasm_memory_size_reference() <= old_size);
+    updated_size_reference =
+        new_size + (wasm_memory_size_reference() - old_size);
+    DCHECK(updated_size_reference <= new_size);
+    Memory::int32_at(pc_) = updated_size_reference;
+  } else {
+    UNREACHABLE();
+  }
   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
     Assembler::FlushICache(isolate_, pc_, sizeof(int64_t));
   }