1 //===- ConstantPool.h - Keep track of assembler-generated ------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the ConstantPool and AssemblerConstantPools classes.
12 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_MC_CONSTANTPOOLS_H
16 #define LLVM_MC_CONSTANTPOOLS_H
18 #include "llvm/ADT/MapVector.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/Support/SMLoc.h"
29 struct ConstantPoolEntry {
30 ConstantPoolEntry(MCSymbol *L, const MCExpr *Val, unsigned Sz, SMLoc Loc_)
31 : Label(L), Value(Val), Size(Sz), Loc(Loc_) {}
38 // A class to keep track of assembler-generated constant pools that are use to
39 // implement the ldr-pseudo.
41 typedef SmallVector<ConstantPoolEntry, 4> EntryVecTy;
45 // Initialize a new empty constant pool
48 // Add a new entry to the constant pool in the next slot.
49 // \param Value is the new entry to put in the constant pool.
50 // \param Size is the size in bytes of the entry
52 // \returns a MCExpr that references the newly inserted value
53 const MCExpr *addEntry(const MCExpr *Value, MCContext &Context,
54 unsigned Size, SMLoc Loc);
56 // Emit the contents of the constant pool using the provided streamer.
57 void emitEntries(MCStreamer &Streamer);
59 // Return true if the constant pool is empty
63 class AssemblerConstantPools {
64 // Map type used to keep track of per-Section constant pools used by the
65 // ldr-pseudo opcode. The map associates a section to its constant pool. The
66 // constant pool is a vector of (label, value) pairs. When the ldr
67 // pseudo is parsed we insert a new (label, value) pair into the constant pool
68 // for the current section and add MCSymbolRefExpr to the new label as
69 // an opcode to the ldr. After we have parsed all the user input we
70 // output the (label, value) pairs in each constant pool at the end of the
73 // We use the MapVector for the map type to ensure stable iteration of
74 // the sections at the end of the parse. We need to iterate over the
75 // sections in a stable order to ensure that we have print the
76 // constant pools in a deterministic order when printing an assembly
78 typedef MapVector<MCSection *, ConstantPool> ConstantPoolMapTy;
79 ConstantPoolMapTy ConstantPools;
82 void emitAll(MCStreamer &Streamer);
83 void emitForCurrentSection(MCStreamer &Streamer);
84 const MCExpr *addEntry(MCStreamer &Streamer, const MCExpr *Expr,
85 unsigned Size, SMLoc Loc);
88 ConstantPool *getConstantPool(MCSection *Section);
89 ConstantPool &getOrCreateConstantPool(MCSection *Section);
91 } // end namespace llvm