1 //===-- WebAssemblyMCLowerPrePass.cpp - Prepare for MC lower --------------===// 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 /// \file 10 /// Some information in MC lowering / asm printing gets generated as 11 /// instructions get emitted, but may be necessary at the start, such as for 12 /// .globaltype declarations. This pass collects this information. 13 /// 14 //===----------------------------------------------------------------------===// 15 16 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h" 17 #include "Utils/WebAssemblyUtilities.h" 18 #include "WebAssembly.h" 19 #include "WebAssemblyMachineFunctionInfo.h" 20 #include "WebAssemblySubtarget.h" 21 #include "llvm/ADT/SCCIterator.h" 22 #include "llvm/CodeGen/MachineFrameInfo.h" 23 #include "llvm/CodeGen/MachineFunction.h" 24 #include "llvm/CodeGen/MachineInstrBuilder.h" 25 #include "llvm/CodeGen/MachineLoopInfo.h" 26 #include "llvm/CodeGen/MachineModuleInfoImpls.h" 27 #include "llvm/CodeGen/MachineRegisterInfo.h" 28 #include "llvm/CodeGen/Passes.h" 29 #include "llvm/Support/Debug.h" 30 #include "llvm/Support/raw_ostream.h" 31 using namespace llvm; 32 33 #define DEBUG_TYPE "wasm-mclower-prepass" 34 35 namespace { 36 class WebAssemblyMCLowerPrePass final : public ModulePass { 37 StringRef getPassName() const override { 38 return "WebAssembly MC Lower Pre Pass"; 39 } 40 41 void getAnalysisUsage(AnalysisUsage &AU) const override { 42 AU.setPreservesCFG(); 43 ModulePass::getAnalysisUsage(AU); 44 } 45 46 bool runOnModule(Module &M) override; 47 48 public: 49 static char ID; // Pass identification, replacement for typeid 50 WebAssemblyMCLowerPrePass() : ModulePass(ID) {} 51 }; 52 } // end anonymous namespace 53 54 char WebAssemblyMCLowerPrePass::ID = 0; 55 INITIALIZE_PASS( 56 WebAssemblyMCLowerPrePass, DEBUG_TYPE, 57 "Collects information ahead of time for MC lowering", 58 false, false) 59 60 ModulePass *llvm::createWebAssemblyMCLowerPrePass() { 61 return new WebAssemblyMCLowerPrePass(); 62 } 63 64 // NOTE: this is a ModulePass since we need to enforce that this code has run 65 // for all functions before AsmPrinter. If this way of doing things is ever 66 // suboptimal, we could opt to make it a MachineFunctionPass and instead use 67 // something like createBarrierNoopPass() to enforce ordering. 68 bool WebAssemblyMCLowerPrePass::runOnModule(Module &M) { 69 auto *MMIWP = getAnalysisIfAvailable<MachineModuleInfoWrapperPass>(); 70 if (!MMIWP) 71 return true; 72 73 MachineModuleInfo &MMI = MMIWP->getMMI(); 74 MachineModuleInfoWasm &MMIW = MMI.getObjFileInfo<MachineModuleInfoWasm>(); 75 76 for (Function &F : M) { 77 MachineFunction *MF = MMI.getMachineFunction(F); 78 if (!MF) 79 continue; 80 81 LLVM_DEBUG(dbgs() << "********** MC Lower Pre Pass **********\n" 82 "********** Function: " 83 << MF->getName() << '\n'); 84 85 for (MachineBasicBlock &MBB : *MF) { 86 for (auto &MI : MBB) { 87 // FIXME: what should all be filtered out beyond these? 88 if (MI.isDebugInstr() || MI.isInlineAsm()) 89 continue; 90 for (MachineOperand &MO : MI.uses()) { 91 if (MO.isSymbol()) { 92 MMIW.MachineSymbolsUsed.insert(MO.getSymbolName()); 93 } 94 } 95 } 96 } 97 } 98 return true; 99 } 100