diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp --- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp +++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp @@ -541,6 +541,7 @@ const RISCVRegisterInfo *RI = STI.getRegisterInfo(); MachineFrameInfo &MFI = MF.getFrameInfo(); auto *RVFI = MF.getInfo(); + const RISCVInstrInfo *TII = STI.getInstrInfo(); Register FPReg = getFPReg(STI); Register SPReg = getSPReg(STI); @@ -606,6 +607,50 @@ adjustReg(MBB, LastFrameDestroy, DL, SPReg, SPReg, SecondSPAdjustAmount, MachineInstr::FrameDestroy); + + // Emit ".cfi_def_cfa_offset FirstSPAdjustAmount" if using an sp-based CFA + if (!hasFP(MF)) { + unsigned CFIIndex = MF.addFrameInst( + MCCFIInstruction::cfiDefCfaOffset(nullptr, -FirstSPAdjustAmount)); + BuildMI(MBB, LastFrameDestroy, DL, + TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + } + } + + if (hasFP(MF)) { + // To find the instruction restoring FP from stack. + for (auto &I = LastFrameDestroy; I != MBBI; ++I) { + if (I->mayLoad() && I->getOperand(0).isReg()) { + Register DestReg = I->getOperand(0).getReg(); + if (DestReg == FPReg) { + // If there is frame pointer, after restoring $fp registers, we + // need adjust CFA back to the correct sp-based offset. + // Emit ".cfi_def_cfa $sp, CFAOffset" + uint64_t CFAOffset = + FirstSPAdjustAmount + ? FirstSPAdjustAmount + RVFI->getVarArgsSaveSize() + : FPOffset; + unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::cfiDefCfa( + nullptr, RI->getDwarfRegNum(SPReg, true), CFAOffset)); + BuildMI(MBB, std::next(I), DL, + TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + break; + } + } + } + } + + // Add CFI directives for callee-saved registers. + // Iterate over list of callee-saved registers and emit .cfi_restore + // directives. + for (const auto &Entry : CSI) { + Register Reg = Entry.getReg(); + unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::createRestore( + nullptr, RI->getDwarfRegNum(Reg, true))); + BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); } if (FirstSPAdjustAmount) @@ -616,6 +661,13 @@ // Emit epilogue for shadow call stack. emitSCSEpilogue(MF, MBB, MBBI, DL); + + // After restoring $sp, we need to adjust CFA to $(sp + 0) + // Emit ".cfi_def_cfa_offset 0" + unsigned CFIIndex = + MF.addFrameInst(MCCFIInstruction::cfiDefCfaOffset(nullptr, 0)); + BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); } StackOffset