Reland D147524 "[LoongArch] Provide basic TargetTransformInfo implementation"

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

Reviewed By: SixWeining, xen0n

Differential Revision: https://reviews.llvm.org/D147524

llvm/lib/Target/LoongArch/CMakeLists.txt

@@ -26,6 +26,7 @@ add_llvm_target(LoongArchCodeGen
   LoongArchRegisterInfo.cpp
   LoongArchSubtarget.cpp
   LoongArchTargetMachine.cpp
+  LoongArchTargetTransformInfo.cpp
 
   LINK_COMPONENTS
   Analysis

llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp

@@ -13,8 +13,10 @@
 #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"
@@ -149,6 +151,11 @@ bool LoongArchPassConfig::addInstSelector() {
   return false;
 }
 
+TargetTransformInfo
+LoongArchTargetMachine::getTargetTransformInfo(const Function &F) const {
+  return TargetTransformInfo(LoongArchTTIImpl(this, F));
+}
+
 void LoongArchPassConfig::addPreEmitPass() { addPass(&BranchRelaxationPassID); }
 
 void LoongArchPassConfig::addPreEmitPass2() {

llvm/lib/Target/LoongArch/LoongArchTargetMachine.h

@@ -31,6 +31,7 @@ public:
                          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;
 

llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.cpp

@@ -0,0 +1,22 @@
+//===-- 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.

llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.h

@@ -0,0 +1,47 @@
+//===- 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