llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp

   1 //===-- Target.cpp ----------------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 #include "../Target.h"
   9 #include "AArch64.h"
  10 #include "AArch64RegisterInfo.h"
  11
  12 namespace llvm {
  13 namespace exegesis {
  14
  15 static unsigned getLoadImmediateOpcode(unsigned RegBitWidth) {
  16   switch (RegBitWidth) {
  17   case 32:
  18     return AArch64::MOVi32imm;
  19   case 64:
  20     return AArch64::MOVi64imm;
  21   }
  22   llvm_unreachable("Invalid Value Width");
  23 }
  24
  25 // Generates instruction to load an immediate value into a register.
  26 static MCInst loadImmediate(unsigned Reg, unsigned RegBitWidth,
  27                             const APInt &Value) {
  28   if (Value.getBitWidth() > RegBitWidth)
  29     llvm_unreachable("Value must fit in the Register");
  30   return MCInstBuilder(getLoadImmediateOpcode(RegBitWidth))
  31       .addReg(Reg)
  32       .addImm(Value.getZExtValue());
  33 }
  34
  35 #include "AArch64GenExegesis.inc"
  36
  37 namespace {
  38
  39 class ExegesisAArch64Target : public ExegesisTarget {
  40 public:
  41   ExegesisAArch64Target() : ExegesisTarget(AArch64CpuPfmCounters) {}
  42
  43 private:
  44   std::vector<MCInst> setRegTo(const MCSubtargetInfo &STI, unsigned Reg,
  45                                const APInt &Value) const override {
  46     if (AArch64::GPR32RegClass.contains(Reg))
  47       return {loadImmediate(Reg, 32, Value)};
  48     if (AArch64::GPR64RegClass.contains(Reg))
  49       return {loadImmediate(Reg, 64, Value)};
  50     errs() << "setRegTo is not implemented, results will be unreliable\n";
  51     return {};
  52   }
  53
  54   bool matchesArch(Triple::ArchType Arch) const override {
  55     return Arch == Triple::aarch64 || Arch == Triple::aarch64_be;
  56   }
  57
  58   void addTargetSpecificPasses(PassManagerBase &PM) const override {
  59     // Function return is a pseudo-instruction that needs to be expanded
  60     PM.add(createAArch64ExpandPseudoPass());
  61   }
  62 };
  63
  64 } // namespace
  65
  66 static ExegesisTarget *getTheExegesisAArch64Target() {
  67   static ExegesisAArch64Target Target;
  68   return &Target;
  69 }
  70
  71 void InitializeAArch64ExegesisTarget() {
  72   ExegesisTarget::registerTarget(getTheExegesisAArch64Target());
  73 }
  74
  75 } // namespace exegesis
  76 } // namespace llvm