xref: /openbsd-src/gnu/llvm/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp (revision a0747c9f67a4ae71ccb71e62a28d1ea19e06a63c)
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
77