llvm/tools/llvm-exegesis/lib/PowerPC/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 // The PowerPC ExegesisTarget.
   8 //===----------------------------------------------------------------------===//
   9 #include "../Target.h"
  10 #include "PPC.h"
  11 #include "PPCRegisterInfo.h"
  12
  13 namespace llvm {
  14 namespace exegesis {
  15
  16 #include "PPCGenExegesis.inc"
  17
  18 namespace {
  19 class ExegesisPowerPCTarget : public ExegesisTarget {
  20 public:
  21   ExegesisPowerPCTarget() : ExegesisTarget(PPCCpuPfmCounters) {}
  22
  23 private:
  24   std::vector<MCInst> setRegTo(const MCSubtargetInfo &STI, unsigned Reg,
  25                                const APInt &Value) const override;
  26   bool matchesArch(Triple::ArchType Arch) const override {
  27     return Arch == Triple::ppc64le;
  28   }
  29 };
  30 } // end anonymous namespace
  31
  32 static unsigned getLoadImmediateOpcode(unsigned RegBitWidth) {
  33   switch (RegBitWidth) {
  34   case 32:
  35     return PPC::LI;
  36   case 64:
  37     return PPC::LI8;
  38   }
  39   llvm_unreachable("Invalid Value Width");
  40 }
  41
  42 // Generates instruction to load an immediate value into a register.
  43 static MCInst loadImmediate(unsigned Reg, unsigned RegBitWidth,
  44                             const APInt &Value) {
  45   if (Value.getBitWidth() > RegBitWidth)
  46     llvm_unreachable("Value must fit in the Register");
  47   return MCInstBuilder(getLoadImmediateOpcode(RegBitWidth))
  48       .addReg(Reg)
  49       .addImm(Value.getZExtValue());
  50 }
  51
  52 std::vector<MCInst> ExegesisPowerPCTarget::setRegTo(const MCSubtargetInfo &STI,
  53                                                     unsigned Reg,
  54                                                     const APInt &Value) const {
  55   if (PPC::GPRCRegClass.contains(Reg))
  56     return {loadImmediate(Reg, 32, Value)};
  57   if (PPC::G8RCRegClass.contains(Reg))
  58     return {loadImmediate(Reg, 64, Value)};
  59   errs() << "setRegTo is not implemented, results will be unreliable\n";
  60   return {};
  61 }
  62
  63 static ExegesisTarget *getTheExegesisPowerPCTarget() {
  64   static ExegesisPowerPCTarget Target;
  65   return &Target;
  66 }
  67
  68 void InitializePowerPCExegesisTarget() {
  69   ExegesisTarget::registerTarget(getTheExegesisPowerPCTarget());
  70 }
  71
  72 } // namespace exegesis
  73 } // namespace llvm