[LoongArch] Provide basic TargetTransformInfo implementation

[zhaoqi5]

Summary

This patch only provides basic LoongArchTTIImpl, and more hooks
will be added to provide TTI machinery for LoongArch soon.

[SixWeining]

LGTM. I just amended the title and commit message a little.

[xen0n]

Trivial enough, thanks!

llvm/lib/Target/LoongArch/CMakeLists.txt

add_llvm_target(LoongArchCodeGen
   LoongArchFrameLowering.cpp
   LoongArchInstrInfo.cpp
   LoongArchISelDAGToDAG.cpp
   LoongArchISelLowering.cpp
   LoongArchMCInstLower.cpp
   LoongArchRegisterInfo.cpp
   LoongArchSubtarget.cpp
   LoongArchTargetMachine.cpp
+  LoongArchTargetTransformInfo.cpp
 
   LINK_COMPONENTS
   Analysis
   AsmPrinter
   CodeGen
   CodeGenTypes
   Core
   LoongArchDesc

llvm/lib/Target/LoongArch/LoongArchTargetMachine.h

 public:
   LoongArchTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
                          StringRef FS, const TargetOptions &Options,
                          std::optional<Reloc::Model> RM,
                          std::optional<CodeModel::Model> CM,
                          CodeGenOpt::Level OL, bool JIT);
   ~LoongArchTargetMachine() override;
 
+  TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
   const LoongArchSubtarget *getSubtargetImpl(const Function &F) const override;
   const LoongArchSubtarget *getSubtargetImpl() const = delete;
 
   // Pass Pipeline Configuration
   TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
 
   TargetLoweringObjectFile *getObjFileLowering() const override {
     return TLOF.get();

llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp

 //===-- LoongArchTargetMachine.cpp - Define TargetMachine for LoongArch ---===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // Implements the info about LoongArch target spec.
 //
 //===----------------------------------------------------------------------===//
 
 #include "LoongArchTargetMachine.h"
 #include "LoongArch.h"
 #include "LoongArchMachineFunctionInfo.h"
+#include "LoongArchTargetTransformInfo.h"
 #include "MCTargetDesc/LoongArchBaseInfo.h"
 #include "TargetInfo/LoongArchTargetInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Transforms/Scalar.h"
 #include <optional>
 
 using namespace llvm;

 }
 
 bool LoongArchPassConfig::addInstSelector() {
   addPass(createLoongArchISelDag(getLoongArchTargetMachine()));
 
   return false;
 }
 
+TargetTransformInfo
+LoongArchTargetMachine::getTargetTransformInfo(const Function &F) const {
+  return TargetTransformInfo(LoongArchTTIImpl(this, F));
+}
+
 void LoongArchPassConfig::addPreEmitPass() { addPass(&BranchRelaxationPassID); }
 
 void LoongArchPassConfig::addPreEmitPass2() {
   // Schedule the expansion of AtomicPseudos at the last possible moment,
   // avoiding the possibility for other passes to break the requirements for
   // forward progress in the LL/SC block.
   addPass(createLoongArchExpandAtomicPseudoPass());
 }
 
 void LoongArchPassConfig::addPreRegAlloc() {
   addPass(createLoongArchPreRAExpandPseudoPass());
 }

llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.h

+//===- LoongArchTargetTransformInfo.h - LoongArch specific TTI --*- C++ -*-===//
+//
+// 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
+/// This file a TargetTransformInfo::Concept conforming object specific to the
+/// LoongArch target machine. It uses the target's detailed information to
+/// provide more precise answers to certain TTI queries, while letting the
+/// target independent and default TTI implementations handle the rest.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_LOONGARCH_LOONGARCHTARGETTRANSFORMINFO_H
+#define LLVM_LIB_TARGET_LOONGARCH_LOONGARCHTARGETTRANSFORMINFO_H
+
+#include "LoongArchSubtarget.h"
+#include "LoongArchTargetMachine.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/CodeGen/BasicTTIImpl.h"
+
+namespace llvm {
+
+class LoongArchTTIImpl : public BasicTTIImplBase<LoongArchTTIImpl> {
+  typedef BasicTTIImplBase<LoongArchTTIImpl> BaseT;
+  typedef TargetTransformInfo TTI;
+  friend BaseT;
+
+  const LoongArchSubtarget *ST;
+  const LoongArchTargetLowering *TLI;
+
+  const LoongArchSubtarget *getST() const { return ST; }
+  const LoongArchTargetLowering *getTLI() const { return TLI; }
+
+public:
+  explicit LoongArchTTIImpl(const LoongArchTargetMachine *TM, const Function &F)
+      : BaseT(TM, F.getParent()->getDataLayout()), ST(TM->getSubtargetImpl(F)),
+        TLI(ST->getTargetLowering()) {}
+
+  // TODO: Implement more hooks to provide TTI machinery for LoongArch.
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_LOONGARCH_LOONGARCHTARGETTRANSFORMINFO_H

llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.cpp

+//===-- LoongArchTargetTransformInfo.cpp - LoongArch specific TTI ---------===//
+//
+// 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
+/// This file implements a TargetTransformInfo analysis pass specific to the
+/// LoongArch target machine. It uses the target's detailed information to
+/// provide more precise answers to certain TTI queries, while letting the
+/// target independent and default TTI implementations handle the rest.
+///
+//===----------------------------------------------------------------------===//
+
+#include "LoongArchTargetTransformInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loongarchtti"
+
+// TODO: Implement more hooks to provide TTI machinery for LoongArch.