| 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 "WebAssembly.h" |
| 18 | #include "WebAssemblyMachineFunctionInfo.h" |
| 19 | #include "WebAssemblySubtarget.h" |
| 20 | #include "WebAssemblyUtilities.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 | // |
| 69 | // The information stored here is essential for emitExternalDecls in the Wasm |
| 70 | // AsmPrinter |
| 71 | bool WebAssemblyMCLowerPrePass::runOnModule(Module &M) { |
| 72 | auto *MMIWP = getAnalysisIfAvailable<MachineModuleInfoWrapperPass>(); |
| 73 | if (!MMIWP) |
| 74 | return true; |
| 75 | |
| 76 | MachineModuleInfo &MMI = MMIWP->getMMI(); |
| 77 | MachineModuleInfoWasm &MMIW = MMI.getObjFileInfo<MachineModuleInfoWasm>(); |
| 78 | |
| 79 | for (Function &F : M) { |
| 80 | MachineFunction *MF = MMI.getMachineFunction(F); |
| 81 | if (!MF) |
| 82 | continue; |
| 83 | |
| 84 | LLVM_DEBUG(dbgs() << "********** MC Lower Pre Pass **********\n" |
| 85 | "********** Function: " |
| 86 | << MF->getName() << '\n'); |
| 87 | |
| 88 | for (MachineBasicBlock &MBB : *MF) { |
| 89 | for (auto &MI : MBB) { |
| 90 | // FIXME: what should all be filtered out beyond these? |
| 91 | if (MI.isDebugInstr() || MI.isInlineAsm()) |
| 92 | continue; |
| 93 | for (MachineOperand &MO : MI.uses()) { |
| 94 | if (MO.isSymbol()) { |
| 95 | MMIW.MachineSymbolsUsed.insert(X: MO.getSymbolName()); |
| 96 | } |
| 97 | } |
| 98 | } |
| 99 | } |
| 100 | } |
| 101 | return true; |
| 102 | } |
| 103 |