Index: lib/Target/RISCV/MCTargetDesc/RISCVMCAsmInfo.cpp =================================================================== --- lib/Target/RISCV/MCTargetDesc/RISCVMCAsmInfo.cpp +++ lib/Target/RISCV/MCTargetDesc/RISCVMCAsmInfo.cpp @@ -21,6 +21,7 @@ CommentString = "#"; AlignmentIsInBytes = false; SupportsDebugInformation = true; + ExceptionsType = ExceptionHandling::DwarfCFI; Data16bitsDirective = "\t.half\t"; Data32bitsDirective = "\t.word\t"; } Index: lib/Target/RISCV/MCTargetDesc/RISCVMCTargetDesc.cpp =================================================================== --- lib/Target/RISCV/MCTargetDesc/RISCVMCTargetDesc.cpp +++ lib/Target/RISCV/MCTargetDesc/RISCVMCTargetDesc.cpp @@ -50,7 +50,13 @@ static MCAsmInfo *createRISCVMCAsmInfo(const MCRegisterInfo &MRI, const Triple &TT) { - return new RISCVMCAsmInfo(TT); + MCAsmInfo *MAI = new RISCVMCAsmInfo(TT); + + unsigned SP = MRI.getDwarfRegNum(RISCV::X2, true); + MCCFIInstruction Inst = MCCFIInstruction::createDefCfa(nullptr, SP, 0); + MAI->addInitialFrameState(Inst); + + return MAI; } static MCSubtargetInfo *createRISCVMCSubtargetInfo(const Triple &TT, Index: lib/Target/RISCV/RISCVFrameLowering.cpp =================================================================== --- lib/Target/RISCV/RISCVFrameLowering.cpp +++ lib/Target/RISCV/RISCVFrameLowering.cpp @@ -18,6 +18,7 @@ #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/RegisterScavenging.h" +#include "llvm/MC/MCDwarf.h" using namespace llvm; @@ -96,6 +97,8 @@ MachineFrameInfo &MFI = MF.getFrameInfo(); auto *RVFI = MF.getInfo(); + const RISCVRegisterInfo *RI = STI.getRegisterInfo(); + const RISCVInstrInfo *TII = STI.getInstrInfo(); MachineBasicBlock::iterator MBBI = MBB.begin(); unsigned FPReg = getFPReg(STI); @@ -119,6 +122,12 @@ // Allocate space on the stack if necessary. adjustReg(MBB, MBBI, DL, SPReg, SPReg, -StackSize, MachineInstr::FrameSetup); + // Emit ".cfi_def_cfa_offset StackSize" + unsigned CFIIndex = MF.addFrameInst( + MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize)); + BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + // The frame pointer is callee-saved, and code has been generated for us to // save it to the stack. We need to skip over the storing of callee-saved // registers as the frame pointer must be modified after it has been saved @@ -128,10 +137,28 @@ const std::vector &CSI = MFI.getCalleeSavedInfo(); std::advance(MBBI, CSI.size()); + // Iterate over list of callee-saved registers and emit .cfi_offset + // directives. + for (const auto &Entry : CSI) { + int64_t Offset = MFI.getObjectOffset(Entry.getFrameIdx()); + unsigned Reg = Entry.getReg(); + unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::createOffset( + nullptr, RI->getDwarfRegNum(Reg, true), Offset)); + BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + } + // Generate new FP. - if (hasFP(MF)) + if (hasFP(MF)) { adjustReg(MBB, MBBI, DL, FPReg, SPReg, StackSize - RVFI->getVarArgsSaveSize(), MachineInstr::FrameSetup); + + // Emit ".cfi_def_cfa $fp, 0" + unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::createDefCfa( + nullptr, RI->getDwarfRegNum(FPReg, true), 0)); + BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + } } void RISCVFrameLowering::emitEpilogue(MachineFunction &MF, @@ -141,6 +168,7 @@ MachineFrameInfo &MFI = MF.getFrameInfo(); auto *RVFI = MF.getInfo(); DebugLoc DL = MBBI->getDebugLoc(); + const RISCVInstrInfo *TII = STI.getInstrInfo(); unsigned FPReg = getFPReg(STI); unsigned SPReg = getSPReg(STI); @@ -161,8 +189,25 @@ MachineInstr::FrameDestroy); } + if (hasFP(MF)) { + // If there is frame pointer, before restoring callee-saved registers, we + // need adjust CFA to ($sp - FPOffset). emit ".cfi_def_cfa $sp, -FPOffset" + uint64_t FPOffset = StackSize - RVFI->getVarArgsSaveSize(); + unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::createDefCfa( + nullptr, RI->getDwarfRegNum(SPReg, true), -FPOffset)); + BuildMI(MBB, LastFrameDestroy, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); + } + // Deallocate stack adjustReg(MBB, MBBI, DL, SPReg, SPReg, StackSize, MachineInstr::FrameDestroy); + + // After restoring $sp, we need to adjust CFA to $(sp + 0) + // Emit ".cfi_def_cfa_offset 0" + unsigned CFIIndex = + MF.addFrameInst(MCCFIInstruction::createDefCfaOffset(nullptr, 0)); + BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION)) + .addCFIIndex(CFIIndex); } int RISCVFrameLowering::getFrameIndexReference(const MachineFunction &MF, Index: test/CodeGen/RISCV/frame-info.ll =================================================================== --- /dev/null +++ test/CodeGen/RISCV/frame-info.ll @@ -0,0 +1,18 @@ +; RUN: llc -mtriple=riscv32 < %s | FileCheck %s +; RUN: llc -mtriple=riscv64 < %s | FileCheck %s + +define void @foo(i32 signext %size) { +; CHECK: .cfi_startproc +; CHECK: .cfi_def_cfa_offset 16 +; CHECK: .cfi_offset ra, -4 +; CHECK: .cfi_offset s0, -8 +; CHECK: .cfi_def_cfa s0, 0 +entry: + %0 = alloca i8, i32 %size, align 16 + call void @bar(i8* nonnull %0) #2 + ret void +; CHECK: .cfi_def_cfa sp, 16 +; CHECK: .cfi_def_cfa_offset 0 +} + +declare void @bar(i8*)