7 files changed, 99 insertions, 4 deletions
diff --git a/llvm/lib/Target/AVR/AVRISelLowering.cpp b/llvm/lib/Target/AVR/AVRISelLowering.cpp
index 3955f2a..25ad9ec 100644
--- a/llvm/lib/Target/AVR/AVRISelLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRISelLowering.cpp
@@ -669,7 +669,7 @@ SDValue AVRTargetLowering::getAVRCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
       default: {
         // Turn lhs < rhs with lhs constant into rhs >= lhs+1, this allows
         // us to  fold the constant into the cmp instruction.
-        RHS = DAG.getConstant(C->getSExtValue() + 1, DL, VT);
+        RHS = DAG.getSignedConstant(C->getSExtValue() + 1, DL, VT);
         CC = ISD::SETGE;
         break;
       }
@@ -713,7 +713,10 @@ SDValue AVRTargetLowering::getAVRCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
     // Turn lhs < rhs with lhs constant into rhs >= lhs+1, this allows us to
     // fold the constant into the cmp instruction.
     if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS)) {
-      RHS = DAG.getConstant(C->getSExtValue() + 1, DL, VT);
+      // Doing a "icmp ugt i16 65535, %0" comparison should have been converted
+      // already to something else. Assert to make sure this assumption holds.
+      assert((!C->isAllOnes()) && "integer overflow in comparison transform");
+      RHS = DAG.getConstant(C->getZExtValue() + 1, DL, VT);
       CC = ISD::SETUGE;
       break;
     }
diff --git a/llvm/lib/Target/AVR/AVRISelLowering.h b/llvm/lib/Target/AVR/AVRISelLowering.h
index 2ae22b2..301ce9c 100644
--- a/llvm/lib/Target/AVR/AVRISelLowering.h
+++ b/llvm/lib/Target/AVR/AVRISelLowering.h
@@ -94,6 +94,8 @@ public:
     return ShiftLegalizationStrategy::LowerToLibcall;
   }
 
+  bool softPromoteHalfType() const override { return true; }
+
 private:
   SDValue getAVRCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC, SDValue &AVRcc,
                     SelectionDAG &DAG, SDLoc dl) const;
diff --git a/llvm/lib/Target/AVR/AVRTargetMachine.cpp b/llvm/lib/Target/AVR/AVRTargetMachine.cpp
index b75417a..02212d2 100644
--- a/llvm/lib/Target/AVR/AVRTargetMachine.cpp
+++ b/llvm/lib/Target/AVR/AVRTargetMachine.cpp
@@ -20,6 +20,7 @@
 #include "AVR.h"
 #include "AVRMachineFunctionInfo.h"
 #include "AVRTargetObjectFile.h"
+#include "AVRTargetTransformInfo.h"
 #include "MCTargetDesc/AVRMCTargetDesc.h"
 #include "TargetInfo/AVRTargetInfo.h"
 
@@ -28,7 +29,7 @@
 namespace llvm {
 
 static const char *AVRDataLayout =
-    "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8";
+    "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-n16:8-a:8";
 
 /// Processes a CPU name.
 static StringRef getCPU(StringRef CPU) {
@@ -62,7 +63,9 @@ namespace {
 class AVRPassConfig : public TargetPassConfig {
 public:
   AVRPassConfig(AVRTargetMachine &TM, PassManagerBase &PM)
-      : TargetPassConfig(TM, PM) {}
+      : TargetPassConfig(TM, PM) {
+    EnableLoopTermFold = true;
+  }
 
   AVRTargetMachine &getAVRTargetMachine() const {
     return getTM<AVRTargetMachine>();
@@ -107,6 +110,11 @@ const AVRSubtarget *AVRTargetMachine::getSubtargetImpl(const Function &) const {
   return &SubTarget;
 }
 
+TargetTransformInfo
+AVRTargetMachine::getTargetTransformInfo(const Function &F) const {
+  return TargetTransformInfo(std::make_unique<AVRTTIImpl>(this, F));
+}
+
 MachineFunctionInfo *AVRTargetMachine::createMachineFunctionInfo(
     BumpPtrAllocator &Allocator, const Function &F,
     const TargetSubtargetInfo *STI) const {
diff --git a/llvm/lib/Target/AVR/AVRTargetMachine.h b/llvm/lib/Target/AVR/AVRTargetMachine.h
index 167d007..9452b3d 100644
--- a/llvm/lib/Target/AVR/AVRTargetMachine.h
+++ b/llvm/lib/Target/AVR/AVRTargetMachine.h
@@ -48,6 +48,8 @@ public:
   createMachineFunctionInfo(BumpPtrAllocator &Allocator, const Function &F,
                             const TargetSubtargetInfo *STI) const override;
 
+  TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
+
   bool isNoopAddrSpaceCast(unsigned SrcAs, unsigned DestAs) const override {
     // While AVR has different address spaces, they are all represented by
     // 16-bit pointers that can be freely casted between (of course, a pointer
diff --git a/llvm/lib/Target/AVR/AVRTargetTransformInfo.cpp b/llvm/lib/Target/AVR/AVRTargetTransformInfo.cpp
new file mode 100644
index 0000000..4dd8660
--- /dev/null
+++ b/llvm/lib/Target/AVR/AVRTargetTransformInfo.cpp
@@ -0,0 +1,25 @@
+//===-- AVRTargetTransformInfo.cpp - AVR 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AVRTargetTransformInfo.h"
+#include "llvm/CodeGen/CostTable.h"
+
+using namespace llvm;
+
+bool AVRTTIImpl::isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                               const TargetTransformInfo::LSRCost &C2) const {
+  // AVR specific here are "instruction number 1st priority".
+  // If we need to emit adds inside the loop to add up base registers, then
+  // we need at least one extra temporary register.
+  unsigned C1NumRegs = C1.NumRegs + (C1.NumBaseAdds != 0);
+  unsigned C2NumRegs = C2.NumRegs + (C2.NumBaseAdds != 0);
+  return std::tie(C1.Insns, C1NumRegs, C1.AddRecCost, C1.NumIVMuls,
+                  C1.NumBaseAdds, C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
+         std::tie(C2.Insns, C2NumRegs, C2.AddRecCost, C2.NumIVMuls,
+                  C2.NumBaseAdds, C2.ScaleCost, C2.ImmCost, C2.SetupCost);
+}
diff --git a/llvm/lib/Target/AVR/AVRTargetTransformInfo.h b/llvm/lib/Target/AVR/AVRTargetTransformInfo.h
new file mode 100644
index 0000000..0daeeb8
--- /dev/null
+++ b/llvm/lib/Target/AVR/AVRTargetTransformInfo.h
@@ -0,0 +1,51 @@
+//===- AVRTargetTransformInfo.h - AVR 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 defines a TargetTransformInfoImplBase conforming object specific
+/// to the AVR 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_AVR_AVRTARGETTRANSFORMINFO_H
+#define LLVM_LIB_TARGET_AVR_AVRTARGETTRANSFORMINFO_H
+
+#include "AVRSubtarget.h"
+#include "AVRTargetMachine.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/CodeGen/BasicTTIImpl.h"
+#include "llvm/IR/Function.h"
+#include <optional>
+
+namespace llvm {
+
+class AVRTTIImpl final : public BasicTTIImplBase<AVRTTIImpl> {
+  using BaseT = BasicTTIImplBase<AVRTTIImpl>;
+  using TTI = TargetTransformInfo;
+
+  friend BaseT;
+
+  const AVRSubtarget *ST;
+  const AVRTargetLowering *TLI;
+
+  const AVRSubtarget *getST() const { return ST; }
+  const AVRTargetLowering *getTLI() const { return TLI; }
+
+public:
+  explicit AVRTTIImpl(const AVRTargetMachine *TM, const Function &F)
+      : BaseT(TM, F.getDataLayout()), ST(TM->getSubtargetImpl(F)),
+        TLI(ST->getTargetLowering()) {}
+
+  bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                     const TargetTransformInfo::LSRCost &C2) const override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_AVR_AVRTARGETTRANSFORMINFO_H
diff --git a/llvm/lib/Target/AVR/CMakeLists.txt b/llvm/lib/Target/AVR/CMakeLists.txt
index 781dac0..a31c545 100644
--- a/llvm/lib/Target/AVR/CMakeLists.txt
+++ b/llvm/lib/Target/AVR/CMakeLists.txt
@@ -29,11 +29,13 @@ add_llvm_target(AVRCodeGen
   AVRSubtarget.cpp
   AVRTargetMachine.cpp
   AVRTargetObjectFile.cpp
+  AVRTargetTransformInfo.cpp
 
   DEPENDS
   intrinsics_gen
 
   LINK_COMPONENTS
+  Analysis
   AVRDesc
   AVRInfo
   AsmPrinter
@@ -44,6 +46,8 @@ add_llvm_target(AVRCodeGen
   SelectionDAG
   Support
   Target
+  TargetParser
+  TransformUtils
 
   ADD_TO_COMPONENT
   AVR