1 //===-- RISCVMCExpr.h - RISC-V specific MC expression classes----*- 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 //
9 // This file describes RISC-V specific MCExprs, used for modifiers like
10 // "%hi" or "%lo" etc.,
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_RISCV_MCTARGETDESC_RISCVMCEXPR_H
15 #define LLVM_LIB_TARGET_RISCV_MCTARGETDESC_RISCVMCEXPR_H
16 
17 #include "llvm/MC/MCExpr.h"
18 
19 namespace llvm {
20 
21 class StringRef;
22 
23 class RISCVMCExpr : public MCTargetExpr {
24 public:
25   enum VariantKind {
26     VK_RISCV_None,
27     VK_RISCV_LO,
28     VK_RISCV_HI,
29     VK_RISCV_PCREL_LO,
30     VK_RISCV_PCREL_HI,
31     VK_RISCV_GOT_HI,
32     VK_RISCV_TPREL_LO,
33     VK_RISCV_TPREL_HI,
34     VK_RISCV_TPREL_ADD,
35     VK_RISCV_TLS_GOT_HI,
36     VK_RISCV_TLS_GD_HI,
37     VK_RISCV_CALL,
38     VK_RISCV_CALL_PLT,
39     VK_RISCV_32_PCREL,
40     VK_RISCV_TLSDESC_HI,
41     VK_RISCV_TLSDESC_LOAD_LO,
42     VK_RISCV_TLSDESC_ADD_LO,
43     VK_RISCV_TLSDESC_CALL,
44     VK_RISCV_Invalid // Must be the last item
45   };
46 
47 private:
48   const MCExpr *Expr;
49   const VariantKind Kind;
50 
51   int64_t evaluateAsInt64(int64_t Value) const;
52 
RISCVMCExpr(const MCExpr * Expr,VariantKind Kind)53   explicit RISCVMCExpr(const MCExpr *Expr, VariantKind Kind)
54       : Expr(Expr), Kind(Kind) {}
55 
56 public:
57   static const RISCVMCExpr *create(const MCExpr *Expr, VariantKind Kind,
58                                    MCContext &Ctx);
59 
getKind()60   VariantKind getKind() const { return Kind; }
61 
getSubExpr()62   const MCExpr *getSubExpr() const { return Expr; }
63 
64   /// Get the corresponding PC-relative HI fixup that a VK_RISCV_PCREL_LO
65   /// points to, and optionally the fragment containing it.
66   ///
67   /// \returns nullptr if this isn't a VK_RISCV_PCREL_LO pointing to a
68   /// known PC-relative HI fixup.
69   const MCFixup *getPCRelHiFixup(const MCFragment **DFOut) const;
70 
71   void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
72   bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
73                                  const MCFixup *Fixup) const override;
74   void visitUsedExpr(MCStreamer &Streamer) const override;
findAssociatedFragment()75   MCFragment *findAssociatedFragment() const override {
76     return getSubExpr()->findAssociatedFragment();
77   }
78 
79   void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
80 
81   bool evaluateAsConstant(int64_t &Res) const;
82 
classof(const MCExpr * E)83   static bool classof(const MCExpr *E) {
84     return E->getKind() == MCExpr::Target;
85   }
86 
87   static VariantKind getVariantKindForName(StringRef name);
88   static StringRef getVariantKindName(VariantKind Kind);
89 };
90 
91 } // end namespace llvm.
92 
93 #endif
94