wasm: change the module memory size to be multiples of the page size, 64k.

src/wasm/wasm-module.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_WASM_MODULE_H_
 #define V8_WASM_MODULE_H_
 
 #include "src/wasm/wasm-opcodes.h"
 #include "src/wasm/wasm-result.h"
 
@@ skipping 85 matching lines @@
   uint32_t dest_addr;      // destination memory address of the data.
   uint32_t source_offset;  // start offset in the module bytes.
   uint32_t source_size;    // end offset in the module bytes.
   bool init;               // true if loaded upon instantiation.
 };
 
 enum ModuleOrigin { kWasmOrigin, kAsmJsOrigin };
 
 // Static representation of a module.
 struct WasmModule {
-  static const uint8_t kMinMemSize = 12;  // Minimum memory size = 4kb
-  static const uint8_t kMaxMemSize = 30;  // Maximum memory size = 1gb
+  static const uint32_t kPageSize = 0x10000;    // Page size, 64kb.
+  static const uint32_t kMinMemPages = 1;       // Minimum memory size = 64kb
+  static const uint32_t kMaxMemPages = 16384;   // Maximum memory size =  1gb
 
   Isolate* shared_isolate;    // isolate for storing shared code.
   const byte* module_start;   // starting address for the module bytes.
   const byte* module_end;     // end address for the module bytes.
-  uint8_t min_mem_size_log2;  // minimum size of the memory (log base 2).
-  uint8_t max_mem_size_log2;  // maximum size of the memory (log base 2).
+  uint32_t min_mem_pages;     // minimum size of the memory in 64k pages.
+  uint32_t max_mem_pages;     // maximum size of the memory in 64k pages.
   bool mem_export;            // true if the memory is exported.
   bool mem_external;          // true if the memory is external.
   int start_function_index;   // start function, if any.
   ModuleOrigin origin;        // origin of the module
 
   std::vector<WasmGlobal> globals;             // globals in this module.
   std::vector<FunctionSig*> signatures;        // signatures in this module.
   std::vector<WasmFunction> functions;         // functions in this module.
   std::vector<WasmDataSegment> data_segments;  // data segments in this module.
   std::vector<uint16_t> function_table;        // function table.
@@ skipping 124 matching lines @@
 
 // For testing. Decode, verify, and run the last exported function in the
 // given decoded module.
 int32_t CompileAndRunWasmModule(Isolate* isolate, WasmModule* module);
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_MODULE_H_