1 //===-- RISCVMCExpr.h - RISCV 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 RISCV-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_Invalid // Must be the last item
41   };
42 
43 private:
44   const MCExpr *Expr;
45   const VariantKind Kind;
46 
47   int64_t evaluateAsInt64(int64_t Value) const;
48 
49   explicit RISCVMCExpr(const MCExpr *Expr, VariantKind Kind)
50       : Expr(Expr), Kind(Kind) {}
51 
52 public:
53   static const RISCVMCExpr *create(const MCExpr *Expr, VariantKind Kind,
54                                    MCContext &Ctx);
55 
56   VariantKind getKind() const { return Kind; }
57 
58   const MCExpr *getSubExpr() const { return Expr; }
59 
60   /// Get the corresponding PC-relative HI fixup that a VK_RISCV_PCREL_LO
61   /// points to, and optionally the fragment containing it.
62   ///
63   /// \returns nullptr if this isn't a VK_RISCV_PCREL_LO pointing to a
64   /// known PC-relative HI fixup.
65   const MCFixup *getPCRelHiFixup(const MCFragment **DFOut) const;
66 
67   void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
68   bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
69                                  const MCFixup *Fixup) const override;
70   void visitUsedExpr(MCStreamer &Streamer) const override;
71   MCFragment *findAssociatedFragment() const override {
72     return getSubExpr()->findAssociatedFragment();
73   }
74 
75   void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
76 
77   bool evaluateAsConstant(int64_t &Res) const;
78 
79   static bool classof(const MCExpr *E) {
80     return E->getKind() == MCExpr::Target;
81   }
82 
83   static bool classof(const RISCVMCExpr *) { return true; }
84 
85   static VariantKind getVariantKindForName(StringRef name);
86   static StringRef getVariantKindName(VariantKind Kind);
87 };
88 
89 } // end namespace llvm.
90 
91 #endif
92