1 files changed, 123 insertions, 0 deletions
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerIntrinsics.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerIntrinsics.cpp
new file mode 100644
index 00000000000..f5ed66bcebc
--- /dev/null
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerIntrinsics.cpp
@@ -0,0 +1,123 @@
+//===-- AMDGPULowerIntrinsics.cpp -----------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Transforms/Utils/LowerMemIntrinsics.h"
+
+#define DEBUG_TYPE "amdgpu-lower-intrinsics"
+
+using namespace llvm;
+
+namespace {
+
+const unsigned MaxStaticSize = 1024;
+
+class AMDGPULowerIntrinsics : public ModulePass {
+public:
+  static char ID;
+
+  AMDGPULowerIntrinsics() : ModulePass(ID) { }
+  bool runOnModule(Module &M) override;
+  StringRef getPassName() const override {
+    return "AMDGPU Lower Intrinsics";
+  }
+};
+
+}
+
+char AMDGPULowerIntrinsics::ID = 0;
+
+char &llvm::AMDGPULowerIntrinsicsID = AMDGPULowerIntrinsics::ID;
+
+INITIALIZE_PASS(AMDGPULowerIntrinsics, DEBUG_TYPE,
+                "Lower intrinsics", false, false)
+
+// TODO: Should refine based on estimated number of accesses (e.g. does it
+// require splitting based on alignment)
+static bool shouldExpandOperationWithSize(Value *Size) {
+  ConstantInt *CI = dyn_cast<ConstantInt>(Size);
+  return !CI || (CI->getZExtValue() > MaxStaticSize);
+}
+
+static bool expandMemIntrinsicUses(Function &F) {
+  Intrinsic::ID ID = F.getIntrinsicID();
+  bool Changed;
+
+  for (auto I = F.user_begin(), E = F.user_end(); I != E;) {
+    Instruction *Inst = cast<Instruction>(*I);
+    ++I;
+
+    switch (ID) {
+    case Intrinsic::memcpy: {
+      auto *Memcpy = cast<MemCpyInst>(Inst);
+      if (shouldExpandOperationWithSize(Memcpy->getLength())) {
+        expandMemCpyAsLoop(Memcpy);
+        Changed = true;
+        Memcpy->eraseFromParent();
+      }
+
+      break;
+    }
+    case Intrinsic::memmove: {
+      auto *Memmove = cast<MemMoveInst>(Inst);
+      if (shouldExpandOperationWithSize(Memmove->getLength())) {
+        expandMemMoveAsLoop(Memmove);
+        Changed = true;
+        Memmove->eraseFromParent();
+      }
+
+      break;
+    }
+    case Intrinsic::memset: {
+      auto *Memset = cast<MemSetInst>(Inst);
+      if (shouldExpandOperationWithSize(Memset->getLength())) {
+        expandMemSetAsLoop(Memset);
+        Changed = true;
+        Memset->eraseFromParent();
+      }
+
+      break;
+    }
+    default:
+      break;
+    }
+  }
+
+  return Changed;
+}
+
+bool AMDGPULowerIntrinsics::runOnModule(Module &M) {
+  bool Changed = false;
+
+  for (Function &F : M) {
+    if (!F.isDeclaration())
+      continue;
+
+    switch (F.getIntrinsicID()) {
+    case Intrinsic::memcpy:
+    case Intrinsic::memmove:
+    case Intrinsic::memset:
+      if (expandMemIntrinsicUses(F))
+        Changed = true;
+      break;
+    default:
+      break;
+    }
+  }
+
+  return Changed;
+}
+
+ModulePass *llvm::createAMDGPULowerIntrinsicsPass() {
+  return new AMDGPULowerIntrinsics();
+}