[llvm] [llvm-jitlink] Fix detectStubKind() for big endian systems (PR #79970)

[Stefan Gränitz via llvm-commits]

https://github.com/weliveindetail created https://github.com/llvm/llvm-project/pull/79970

This function is used in `jitlink-check` lines in LIT tests. In #78371 I missed to swap initial instruction bytes for systems that store the constants as big-endian.

>From 0d5f099a6a15a08b74df5c54cae64c460b683b9e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Gr=C3=A4nitz?= <stefan.graenitz at gmail.com>
Date: Tue, 30 Jan 2024 09:56:27 +0100
Subject: [PATCH] [llvm-jitlink] Fix detectStubKind() for big endian systems

This function is used in jitlink-check lines for LIT testing. In #78371 I missed to swap initial instruction bytes for systems that
store the constants as big-endian.
---
 llvm/tools/llvm-jitlink/llvm-jitlink.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
index b2a133860197d..769ed17ac4cbd 100644
--- a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
+++ b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
@@ -1294,10 +1294,11 @@ class MemoryMatcher {
 };
 
 static StringRef detectStubKind(const Session::MemoryRegionInfo &Stub) {
-  constexpr uint32_t Armv7MovWTle = 0xe300c000;
-  constexpr uint32_t Armv7BxR12le = 0xe12fff1c;
-  constexpr uint32_t Thumbv7MovWTle = 0x0c00f240;
-  constexpr uint16_t Thumbv7BxR12le = 0x4760;
+  using namespace support::endian;
+  auto Armv7MovWTle = byte_swap<uint32_t, endianness::little>(0xe300c000);
+  auto Armv7BxR12le = byte_swap<uint32_t, endianness::little>(0xe12fff1c);
+  auto Thumbv7MovWTle = byte_swap<uint32_t, endianness::little>(0x0c00f240);
+  auto Thumbv7BxR12le = byte_swap<uint16_t, endianness::little>(0x4760);
 
   MemoryMatcher M(Stub.getContent());
   if (M.matchMask(Thumbv7MovWTle)) {