[LoongArch] Emit error messages when using emulated TLS

Reviewed By: SixWeining

Pull Request: #92483

Author: wangleiat

llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp

@@ -945,6 +945,10 @@ LoongArchTargetLowering::lowerGlobalTLSAddress(SDValue Op,
   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
   assert(N->getOffset() == 0 && "unexpected offset in global node");
 
+  if (DAG.getTarget().useEmulatedTLS())
+    report_fatal_error("the emulated TLS is prohibited",
+                       /*GenCrashDiag=*/false);
+
   bool IsDesc = DAG.getTarget().useTLSDESC();
 
   switch (getTargetMachine().getTLSModel(N->getGlobal())) {

llvm/test/CodeGen/LoongArch/emutls.ll

@@ -0,0 +1,11 @@
+; RUN: not llc --mtriple=loongarch64 -emulated-tls -mattr=+d \
+; RUN:     -relocation-model=pic < %s 2>&1 | FileCheck %s
+
+; CHECK: LLVM ERROR: the emulated TLS is prohibited
+
+@x = thread_local global i8 7, align 2
+
+define ptr @get_x() nounwind {
+entry:
+  ret ptr @x
+}