llvm/utils/TableGen/TableGenBackends.h
Tim Northover 69ada669bc AArch64: TableGenerate system instruction operands.
The way the named arguments for various system instructions are handled at the
moment has a few problems:

  - Large-scale duplication between AArch64BaseInfo.h and AArch64BaseInfo.cpp
  - That weird Mapping class that I have no idea what I was on when I thought
    it was a good idea.
  - Searches are performed linearly through the entire list.
  - We print absolutely all registers in upper-case, even though some are
    canonically mixed case (SPSel for example).
  - The ARM ARM specifies sysregs in terms of 5 fields, but those are relegated
    to comments in our implementation, with a slightly opaque hex value
    indicating the canonical encoding LLVM will use.

This adds a new TableGen backend to produce efficiently searchable tables, and
switches AArch64 over to using that infrastructure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274576 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-05 21:23:04 +00:00

87 lines
3.8 KiB
C++

//===- TableGenBackends.h - Declarations for LLVM TableGen Backends -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declarations for all of the LLVM TableGen
// backends. A "TableGen backend" is just a function. See below for a
// precise description.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_UTILS_TABLEGEN_TABLEGENBACKENDS_H
#define LLVM_UTILS_TABLEGEN_TABLEGENBACKENDS_H
// A TableGen backend is a function that looks like
//
// EmitFoo(RecordKeeper &RK, raw_ostream &OS /*, anything else you need */ )
//
// What you do inside of that function is up to you, but it will usually
// involve generating C++ code to the provided raw_ostream.
//
// The RecordKeeper is just a top-level container for an in-memory
// representation of the data encoded in the TableGen file. What a TableGen
// backend does is walk around that in-memory representation and generate
// stuff based on the information it contains.
//
// The in-memory representation is a node-graph (think of it like JSON but
// with a richer ontology of types), where the nodes are subclasses of
// Record. The methods `getClass`, `getDef` are the basic interface to
// access the node-graph. RecordKeeper also provides a handy method
// `getAllDerivedDefinitions`. Consult "include/llvm/TableGen/Record.h" for
// the exact interfaces provided by Record's and RecordKeeper.
//
// A common pattern for TableGen backends is for the EmitFoo function to
// instantiate a class which holds some context for the generation process,
// and then have most of the work happen in that class's methods. This
// pattern partly has historical roots in the previous TableGen backend API
// that involved a class and an invocation like `FooEmitter(RK).run(OS)`.
//
// Remember to wrap private things in an anonymous namespace. For most
// backends, this means that the EmitFoo function is the only thing not in
// the anonymous namespace.
// FIXME: Reorganize TableGen so that build dependencies can be more
// accurately expressed. Currently, touching any of the emitters (or
// anything that they transitively depend on) causes everything dependent
// on TableGen to be rebuilt (this includes all the targets!). Perhaps have
// a standalone TableGen binary and have the backends be loadable modules
// of some sort; then the dependency could be expressed as being on the
// module, and all the modules would have a common dependency on the
// TableGen binary with as few dependencies as possible on the rest of
// LLVM.
namespace llvm {
class raw_ostream;
class RecordKeeper;
void EmitIntrinsics(RecordKeeper &RK, raw_ostream &OS, bool TargetOnly = false);
void EmitAsmMatcher(RecordKeeper &RK, raw_ostream &OS);
void EmitAsmWriter(RecordKeeper &RK, raw_ostream &OS);
void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS);
void EmitCodeEmitter(RecordKeeper &RK, raw_ostream &OS);
void EmitDAGISel(RecordKeeper &RK, raw_ostream &OS);
void EmitDFAPacketizer(RecordKeeper &RK, raw_ostream &OS);
void EmitDisassembler(RecordKeeper &RK, raw_ostream &OS);
void EmitFastISel(RecordKeeper &RK, raw_ostream &OS);
void EmitInstrInfo(RecordKeeper &RK, raw_ostream &OS);
void EmitPseudoLowering(RecordKeeper &RK, raw_ostream &OS);
void EmitRegisterInfo(RecordKeeper &RK, raw_ostream &OS);
void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS);
void EmitMapTable(RecordKeeper &RK, raw_ostream &OS);
void EmitOptParser(RecordKeeper &RK, raw_ostream &OS);
void EmitCTags(RecordKeeper &RK, raw_ostream &OS);
void EmitAttributes(RecordKeeper &RK, raw_ostream &OS);
void EmitSearchableTables(RecordKeeper &RK, raw_ostream &OS);
} // End llvm namespace
#endif