diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -632,8 +632,7 @@
            Triple.getArch() == llvm::Triple::armeb ||
            Triple.getArch() == llvm::Triple::thumb ||
            Triple.getArch() == llvm::Triple::thumbeb ||
-           Triple.getArch() == llvm::Triple::wasm32 ||
-           Triple.getArch() == llvm::Triple::wasm64;
+           Triple.isWasm();
   } else if (Model == "posix")
     return true;
 
@@ -1000,8 +999,7 @@
   if (getTriple().getArch() == llvm::Triple::x86 ||
       getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().getArch() == llvm::Triple::arm ||
-      getTriple().getArch() == llvm::Triple::wasm32 ||
-      getTriple().getArch() == llvm::Triple::wasm64 || getTriple().isAArch64())
+      getTriple().isWasm() || getTriple().isAArch64())
     Res |= SanitizerKind::CFIICall;
   if (getTriple().getArch() == llvm::Triple::x86_64 || getTriple().isAArch64())
     Res |= SanitizerKind::ShadowCallStack;
diff --git a/lld/wasm/InputFiles.cpp b/lld/wasm/InputFiles.cpp
--- a/lld/wasm/InputFiles.cpp
+++ b/lld/wasm/InputFiles.cpp
@@ -576,10 +576,11 @@
   obj = check(lto::InputFile::create(MemoryBufferRef(
       mb.getBuffer(), saver.save(archiveName + mb.getBufferIdentifier()))));
   Triple t(obj->getTargetTriple());
-  if (t.getArch() != Triple::wasm32) {
-    error(toString(this) + ": machine type must be wasm32");
+  if (!t.isWasm()) {
+    error(toString(this) + ": machine type must be wasm32 or wasm64");
     return;
   }
+  config->is64 = t.getArch() == Triple::wasm64;
   std::vector<bool> keptComdats;
   for (StringRef s : obj->getComdatTable())
     keptComdats.push_back(symtab->addComdat(s));
diff --git a/llvm/include/llvm/Object/Wasm.h b/llvm/include/llvm/Object/Wasm.h
--- a/llvm/include/llvm/Object/Wasm.h
+++ b/llvm/include/llvm/Object/Wasm.h
@@ -282,6 +282,7 @@
   bool HasLinkingSection = false;
   bool HasDylinkSection = false;
   bool SeenCodeSection = false;
+  bool HasMemory64 = false;
   wasm::WasmLinkingData LinkingData;
   uint32_t NumImportedGlobals = 0;
   uint32_t NumImportedFunctions = 0;
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -957,6 +957,7 @@
       break;
     case wasm::WASM_EXTERNAL_MEMORY:
       Im.Memory = readLimits(Ctx);
+      if (Im.Memory.Flags & wasm::WASM_LIMITS_FLAG_IS_64) HasMemory64 = true;
       break;
     case wasm::WASM_EXTERNAL_TABLE:
       Im.Table = readTable(Ctx);
@@ -1019,7 +1020,9 @@
   uint32_t Count = readVaruint32(Ctx);
   Memories.reserve(Count);
   while (Count--) {
-    Memories.push_back(readLimits(Ctx));
+    auto Limits = readLimits(Ctx);
+    if (Limits.Flags & wasm::WASM_LIMITS_FLAG_IS_64) HasMemory64 = true;
+    Memories.push_back(Limits);
   }
   if (Ctx.Ptr != Ctx.End)
     return make_error<GenericBinaryError>("Memory section ended prematurely",
@@ -1576,11 +1579,15 @@
   return section_iterator(SectionRef(Ref, this));
 }
 
-uint8_t WasmObjectFile::getBytesInAddress() const { return 4; }
+uint8_t WasmObjectFile::getBytesInAddress() const {
+  return HasMemory64 ? 8 : 4;
+}
 
 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; }
 
-Triple::ArchType WasmObjectFile::getArch() const { return Triple::wasm32; }
+Triple::ArchType WasmObjectFile::getArch() const {
+  return HasMemory64 ? Triple::wasm64 : Triple::wasm32;
+}
 
 SubtargetFeatures WasmObjectFile::getFeatures() const {
   return SubtargetFeatures();