LLVM3.0 的 JIT 在 MinGW64 / MSCV64 上，进行代码块重定向阶段，处理超过32位地址范围(前后跳转2GB地址空间)的外部符号地址时，会将其强转为32位：

// lib\Target\X86\X86JITInfo.cpp:543
void X86JITInfo::relocate(void *Function, MachineRelocation *MR,
                          unsigned NumRelocs, unsigned char* GOTBase) {
  for (unsigned i = 0; i != NumRelocs; ++i, ++MR) {
    void *RelocPos = (char*)Function + MR->getMachineCodeOffset();
    intptr_t ResultPtr = (intptr_t)MR->getResultPointer();
    switch ((X86::RelocationType)MR->getRelocationType()) {
    case X86::reloc_pcrel_word: {
      ResultPtr = ResultPtr -(intptr_t)RelocPos - 4 - MR->getConstantVal();
      *((unsigned*)RelocPos) += (unsigned)ResultPtr; // 这里默认都是强转成32位的
      break;
    }
}

这会导致生成的指令，在执行时崩溃，一般表现为段错误。

解决办法：

From bdc19fc6fa1a87a375e5f77e83bc6e712185676a Mon Sep 17 00:00:00 2001
From: zevorn <zevorn@yeah.net>
Date: Wed, 22 May 2024 18:31:30 +0800
Subject: [PATCH 1/4] <fix>(JIT) Fixed a Bug in JIT

Fixed a Bug in JIT processing code block redirection phase for external symbol parsing
---
 lib/ExecutionEngine/JIT/JITEmitter.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index 24020ee..0050b75 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -849,7 +849,11 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
                        << ResultPtr << "]\n");
 
           // If the target REALLY wants a stub for this function, emit it now.
-          if (MR.mayNeedFarStub()) {
+          uintptr_t CurrPtr = getCurrentPCValue();
+          const uintptr_t rang = 2ull * 1024 * 1024 * 1024; // 2GB
+          if (MR.mayNeedFarStub()
+            || ((CurrPtr + rang) < (uintptr_t)ResultPtr)
+            || ((CurrPtr - rang) > (uintptr_t)ResultPtr)) {
             ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
           }
         } else if (MR.isGlobalValue()) {
-- 
2.44.0.windows.1

PS：这个问题似乎在 LLVM 3.1 上面也存在。