================ @@ -0,0 +1,173 @@ +//===- X86SuppressAPXForReloc.cpp - Suppress APX features for relocations -===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +/// \file +/// +/// This pass is added to suppress APX features for relocations. It's used +/// together with disabling emitting APX relocation types for backward +/// compatibility with old version of linker (like before LD 2.43). It can avoid +/// the instructions updated incorrectly by old version of linker if the +/// instructions are with APX EGPR/NDD/NF features + the relocations other than +/// APX ones (like GOTTPOFF). +/// +//===----------------------------------------------------------------------===// + +#include "MCTargetDesc/X86BaseInfo.h" +#include "MCTargetDesc/X86MCTargetDesc.h" +#include "X86.h" +#include "X86RegisterInfo.h" +#include "X86Subtarget.h" + +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineOperand.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/InitializePasses.h" +#include "llvm/Target/TargetMachine.h" + +using namespace llvm; + +#define DEBUG_TYPE "x86-suppress-apx-for-relocation" + +static cl::opt<bool> X86EnableAPXForRelocation( + "x86-enable-apx-for-relocation", + cl::desc("Enable APX features (EGPR, NDD and NF) for instructions with " + "relocations on x86-64 ELF"), + cl::init(false)); + +namespace { +class X86SuppressAPXForRelocationPass : public MachineFunctionPass { +public: + X86SuppressAPXForRelocationPass() : MachineFunctionPass(ID) {} + + StringRef getPassName() const override { + return "X86 Suppress APX features for relocation"; + } + + bool runOnMachineFunction(MachineFunction &MF) override; + + static char ID; +}; +} // namespace + +char X86SuppressAPXForRelocationPass::ID = 0; + +INITIALIZE_PASS_BEGIN(X86SuppressAPXForRelocationPass, DEBUG_TYPE, + "X86 Suppress APX features for relocation", false, false) +INITIALIZE_PASS_END(X86SuppressAPXForRelocationPass, DEBUG_TYPE, + "X86 Suppress APX features for relocation", false, false) + +FunctionPass *llvm::createX86SuppressAPXForRelocationPass() { + return new X86SuppressAPXForRelocationPass(); +} + +static void suppressEGPRRegClass(MachineFunction &MF, MachineInstr &MI, + unsigned int OpNum) { + MachineRegisterInfo *MRI = &MF.getRegInfo(); + auto Reg = MI.getOperand(OpNum).getReg(); + if (!Reg.isVirtual()) { + assert(!X86II::isApxExtendedReg(Reg) && "APX EGPR is used unexpectedly."); + return; + } + + auto *RC = MRI->getRegClass(Reg); + auto *NewRC = X86II::constrainRegClassToNonRex2(RC); + MRI->setRegClass(Reg, NewRC); +} + +bool X86SuppressAPXForRelocationPass::runOnMachineFunction( + MachineFunction &MF) { + if (MF.getTarget().Options.MCOptions.X86APXRelaxRelocations || + X86EnableAPXForRelocation) + return false; + const X86Subtarget &ST = MF.getSubtarget<X86Subtarget>(); + if (!ST.hasEGPR() && !ST.hasNDD() && !ST.hasNF()) ---------------- phoebewang wrote:
Why checking `hasNF`? https://github.com/llvm/llvm-project/pull/136660 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
