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