[llvm] [AMDGPU] Emit the relocation symbol for LDS and named barrier when object linking is enabled (PR #192380)

[Shilei Tian via llvm-commits]

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@@ -330,10 +331,18 @@ void AMDGPUAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
       return;
     }
 
-    // LDS variables aren't emitted in HSA or PAL yet.
     const Triple::OSType OS = TM.getTargetTriple().getOS();
-    if (OS == Triple::AMDHSA || OS == Triple::AMDPAL)
-      return;
+    if (OS == Triple::AMDHSA || OS == Triple::AMDPAL) {
+      if (!AMDGPUTargetMachine::EnableObjectLinking)
+        return;
+      // With object linking, LDS definitions should have been externalized
+      // by earlier passes (e.g. LDS lowering, named barrier lowering).
+      // Only declarations reach here, emitted as SHN_AMDGPU_LDS symbols
+      // so the linker can assign their offsets.
+      assert(GV->isDeclaration() &&
+             "LDS definitions should have been externalized when object "
+             "linking is enabled");
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shiltian wrote:

This needs to be an assertion, because this should not really happen. If that happens, there must be something wrong in the pipeline.

https://github.com/llvm/llvm-project/pull/192380