1 //- WebAssemblyISelDAGToDAG.cpp - A dag to dag inst selector for WebAssembly -//
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 //===----------------------------------------------------------------------===//
11 /// \brief This file defines an instruction selector for the WebAssembly target.
13 //===----------------------------------------------------------------------===//
15 #include "WebAssembly.h"
16 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
17 #include "WebAssemblyTargetMachine.h"
18 #include "llvm/CodeGen/SelectionDAGISel.h"
19 #include "llvm/IR/Function.h" // To access function attributes.
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/MathExtras.h"
22 #include "llvm/Support/raw_ostream.h"
25 #define DEBUG_TYPE "wasm-isel"
27 //===--------------------------------------------------------------------===//
28 /// WebAssembly-specific code to select WebAssembly machine instructions for
29 /// SelectionDAG operations.
32 class WebAssemblyDAGToDAGISel final : public SelectionDAGISel {
33 /// Keep a pointer to the WebAssemblySubtarget around so that we can make the
34 /// right decision when generating code for different targets.
35 const WebAssemblySubtarget *Subtarget;
40 WebAssemblyDAGToDAGISel(WebAssemblyTargetMachine &tm,
41 CodeGenOpt::Level OptLevel)
42 : SelectionDAGISel(tm, OptLevel), Subtarget(nullptr), ForCodeSize(false) {
45 const char *getPassName() const override {
46 return "WebAssembly Instruction Selection";
49 bool runOnMachineFunction(MachineFunction &MF) override {
51 MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize) ||
52 MF.getFunction()->hasFnAttribute(Attribute::MinSize);
53 Subtarget = &MF.getSubtarget<WebAssemblySubtarget>();
54 return SelectionDAGISel::runOnMachineFunction(MF);
57 SDNode *Select(SDNode *Node) override;
60 // add select functions here...
62 } // end anonymous namespace
64 SDNode *WebAssemblyDAGToDAGISel::Select(SDNode *Node) {
65 llvm_unreachable("TODO: implement Select");
68 /// This pass converts a legalized DAG into a WebAssembly-specific DAG, ready
69 /// for instruction scheduling.
70 FunctionPass *llvm::createWebAssemblyISelDag(WebAssemblyTargetMachine &TM,
71 CodeGenOpt::Level OptLevel) {
72 return new WebAssemblyDAGToDAGISel(TM, OptLevel);