[clang] [llvm] AMDGPU: Move enqueued block handling into clang (PR #128519)

[Sameer Sahasrabuddhe via cfe-commits]

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@@ -0,0 +1,110 @@
+//===- AMDGPUExportKernelRuntimeHandles.cpp - Lower enqueued block --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// \file
+//
+// Give any globals used for OpenCL block enqueue runtime handles external
+// linkage so the runtime may access them. These should behave like internal
+// functions for purposes of linking, but need to have an external symbol in the
+// final object for the runtime to access them.
+//
+// TODO: This could be replaced with a new linkage type or global object
+// metadata that produces an external symbol in the final object, but allows
+// rename on IR linking. Alternatively if we can rely on
+// GlobalValue::getGlobalIdentifier we can just make these external symbols to
+// begin with.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPUExportKernelRuntimeHandles.h"
+#include "AMDGPU.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+
+#define DEBUG_TYPE "amdgpu-export-kernel-runtime-handles"
+
+using namespace llvm;
+
+namespace {
+
+/// Lower enqueued blocks.
+class AMDGPUExportKernelRuntimeHandlesLegacy : public ModulePass {
+public:
+  static char ID;
+
+  explicit AMDGPUExportKernelRuntimeHandlesLegacy() : ModulePass(ID) {}
+
+private:
+  bool runOnModule(Module &M) override;
+};
+
+} // end anonymous namespace
+
+char AMDGPUExportKernelRuntimeHandlesLegacy::ID = 0;
+
+char &llvm::AMDGPUExportKernelRuntimeHandlesLegacyID =
+    AMDGPUExportKernelRuntimeHandlesLegacy::ID;
+
+INITIALIZE_PASS(AMDGPUExportKernelRuntimeHandlesLegacy, DEBUG_TYPE,
+                "Externalize enqueued block runtime handles", false, false)
+
+ModulePass *llvm::createAMDGPUExportKernelRuntimeHandlesLegacyPass() {
+  return new AMDGPUExportKernelRuntimeHandlesLegacy();
+}
+
+static bool exportKernelRuntimeHandles(Module &M) {
+  bool Changed = false;
+
+  const StringLiteral HandleSectionName(".amdgpu.kernel.runtime.handle");
+
+  for (GlobalVariable &GV : M.globals()) {
+    if (GV.getSection() == HandleSectionName) {
+      GV.setLinkage(GlobalValue::ExternalLinkage);
+      GV.setDSOLocal(false);
+      Changed = true;
+    }
+  }
+
+  if (!Changed)
+    return false;
+
+  // FIXME: We shouldn't really need to export the kernel address. We can
+  // initialize the runtime handle with the kernel descriptorG
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ssahasra wrote:

Typo at the end of the sentence?

https://github.com/llvm/llvm-project/pull/128519