[WebAssembly] Fixed Disassembler ignoring endian swap on big endian.

Summary: This fixes: https://bugs.llvm.org/show_bug.cgi?id=40620

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57933

llvm-svn: 353496

1 files changed, 2 insertions, 3 deletions

diff --git a/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp b/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
index 2a0ccfc4737..287b2443ddb 100644
--- a/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
+++ b/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
@@ -108,9 +108,8 @@ template <typename T>
 bool parseImmediate(MCInst &MI, uint64_t &Size, ArrayRef<uint8_t> Bytes) {
   if (Size + sizeof(T) > Bytes.size())
     return false;
-  T Val;
-  memcpy(&Val, Bytes.data() + Size, sizeof(T));
-  support::endian::byte_swap<T, support::endianness::little>(Val);
+  T Val = support::endian::read<T, support::endianness::little, alignof(T)>(
+      Bytes.data() + Size);
   Size += sizeof(T);
   if (std::is_floating_point<T>::value) {
     MI.addOperand(MCOperand::createFPImm(static_cast<double>(Val)));