[Hexagon] Implement TargetTransformInfo for Hexagon

Author: Brendon Cahoon <bcahoon@codeaurora.org>
llvm-svn: 244089

lib/Target/Hexagon/CMakeLists.txt

@@ -42,6 +42,7 @@ add_llvm_target(HexagonCodeGen
   HexagonSubtarget.cpp
   HexagonTargetMachine.cpp
   HexagonTargetObjectFile.cpp
+  HexagonTargetTransformInfo.cpp
   HexagonVLIWPacketizer.cpp
 )
 

lib/Target/Hexagon/HexagonTargetMachine.cpp

@@ -16,6 +16,7 @@
 #include "HexagonISelLowering.h"
 #include "HexagonMachineScheduler.h"
 #include "HexagonTargetObjectFile.h"
+#include "HexagonTargetTransformInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
@@ -107,11 +108,43 @@ HexagonTargetMachine::HexagonTargetMachine(const Target &T, const Triple &TT,
                                            CodeGenOpt::Level OL)
     : LLVMTargetMachine(T, "e-m:e-p:32:32-i1:32-i64:64-a:0-n32", TT, CPU, FS,
                         Options, RM, CM, OL),
-      TLOF(make_unique<HexagonTargetObjectFile>()),
-      Subtarget(TT, CPU, FS, *this) {
+      TLOF(make_unique<HexagonTargetObjectFile>()) {
   initAsmInfo();
 }
 
+const HexagonSubtarget *
+HexagonTargetMachine::getSubtargetImpl(const Function &F) const {
+  AttributeSet FnAttrs = F.getAttributes();
+  Attribute CPUAttr =
+      FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-cpu");
+  Attribute FSAttr =
+      FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-features");
+
+  std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
+                        ? CPUAttr.getValueAsString().str()
+                        : TargetCPU;
+  std::string FS = !FSAttr.hasAttribute(Attribute::None)
+                       ? FSAttr.getValueAsString().str()
+                       : TargetFS;
+
+  auto &I = SubtargetMap[CPU + FS];
+  if (!I) {
+    // This needs to be done before we create a new subtarget since any
+    // creation will depend on the TM and the code generation flags on the
+    // function that reside in TargetOptions.
+    resetTargetOptions(F);
+    I = llvm::make_unique<HexagonSubtarget>(TargetTriple, CPU, FS, *this);
+  }
+  return I.get();
+}
+
+TargetIRAnalysis HexagonTargetMachine::getTargetIRAnalysis() {
+  return TargetIRAnalysis([this](Function &F) {
+    return TargetTransformInfo(HexagonTTIImpl(this, F));
+  });
+}
+
+
 HexagonTargetMachine::~HexagonTargetMachine() {}
 
 namespace {

lib/Target/Hexagon/HexagonTargetMachine.h

@@ -24,7 +24,7 @@ class Module;
 
 class HexagonTargetMachine : public LLVMTargetMachine {
   std::unique_ptr<TargetLoweringObjectFile> TLOF;
-  HexagonSubtarget Subtarget;
+  mutable StringMap<std::unique_ptr<HexagonSubtarget>> SubtargetMap;
 
 public:
   HexagonTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
@@ -32,12 +32,12 @@ public:
                        Reloc::Model RM, CodeModel::Model CM,
                        CodeGenOpt::Level OL);
   ~HexagonTargetMachine() override;
-  const HexagonSubtarget *getSubtargetImpl(const Function &) const override {
-    return &Subtarget;
-  }
+  const HexagonSubtarget *getSubtargetImpl(const Function &F) const override;
+
   static unsigned getModuleMatchQuality(const Module &M);
 
   TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
+  TargetIRAnalysis getTargetIRAnalysis() override;
 
   TargetLoweringObjectFile *getObjFileLowering() const override {
     return TLOF.get();

lib/Target/Hexagon/HexagonTargetTransformInfo.cpp

@@ -0,0 +1,44 @@
+//===-- HexagonTargetTransformInfo.cpp - Hexagon specific TTI pass --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+/// \file
+/// This file implements a TargetTransformInfo analysis pass specific to the
+/// Hexagon 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 "HexagonTargetTransformInfo.h"
+#include "llvm/Support/Debug.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "hexagontti"
+
+TargetTransformInfo::PopcntSupportKind
+HexagonTTIImpl::getPopcntSupport(unsigned IntTyWidthInBit) const {
+  // Return Fast Hardware support as every input  < 64 bits will be promoted
+  // to 64 bits.
+  return TargetTransformInfo::PSK_FastHardware;
+}
+
+// The Hexagon target can unroll loops with run-time trip counts.
+void HexagonTTIImpl::getUnrollingPreferences(Loop *L,
+                                             TTI::UnrollingPreferences &UP) {
+  UP.Runtime = UP.Partial = true;
+}
+
+unsigned HexagonTTIImpl::getNumberOfRegisters(bool vector) const {
+  if (vector) {
+    // While its true that v60 has vector registers,
+    // we do not want to advertise it through this API
+    // as it enables LOOP and SLP vectorization.
+    return 0;
+  }
+  return 32;
+}

lib/Target/Hexagon/HexagonTargetTransformInfo.h

@@ -0,0 +1,70 @@
+//===-- HexagonTargetTransformInfo.cpp - Hexagon specific TTI pass --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+/// \file
+/// This file implements a TargetTransformInfo analysis pass specific to the
+/// Hexagon 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_HEXAGON_HEXAGONTARGETTRANSFORMINFO_H
+#define LLVM_LIB_TARGET_HEXAGON_HEXAGONTARGETTRANSFORMINFO_H
+
+#include "Hexagon.h"
+#include "HexagonTargetMachine.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/CodeGen/BasicTTIImpl.h"
+#include "llvm/Target/TargetLowering.h"
+
+namespace llvm {
+
+class HexagonTTIImpl : public BasicTTIImplBase<HexagonTTIImpl> {
+  typedef BasicTTIImplBase<HexagonTTIImpl> BaseT;
+  typedef TargetTransformInfo TTI;
+  friend BaseT;
+
+  const HexagonSubtarget *ST;
+  const HexagonTargetLowering *TLI;
+
+  const HexagonSubtarget *getST() const { return ST; }
+  const HexagonTargetLowering *getTLI() const { return TLI; }
+
+public:
+  explicit HexagonTTIImpl(const HexagonTargetMachine *TM, Function &F)
+      : BaseT(TM, F.getParent()->getDataLayout()), ST(TM->getSubtargetImpl(F)),
+        TLI(ST->getTargetLowering()) {}
+
+  // Provide value semantics. MSVC requires that we spell all of these out.
+  HexagonTTIImpl(const HexagonTTIImpl &Arg)
+      : BaseT(static_cast<const BaseT &>(Arg)), ST(Arg.ST), TLI(Arg.TLI) {}
+  HexagonTTIImpl(HexagonTTIImpl &&Arg)
+      : BaseT(std::move(static_cast<BaseT &>(Arg))), ST(std::move(Arg.ST)),
+        TLI(std::move(Arg.TLI)) {}
+
+  /// \name Scalar TTI Implementations
+  /// @{
+
+  TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) const;
+
+  // The Hexagon target can unroll loops with run-time trip counts.
+  void getUnrollingPreferences(Loop *L, TTI::UnrollingPreferences &UP);
+
+  /// @}
+
+  /// \name Vector TTI Implementations
+  /// @{
+
+  unsigned getNumberOfRegisters(bool vector) const;
+
+  /// @}
+};
+
+} // end namespace llvm
+
+#endif