Date: Fri, 3 Jan 2020 20:19:17 +0000 (UTC) From: Dimitry Andric <dim@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r356331 - head/contrib/llvm-project/llvm/lib/Target/RISCV Message-ID: <202001032019.003KJHd8096183@repo.freebsd.org>
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Author: dim Date: Fri Jan 3 20:19:17 2020 New Revision: 356331 URL: https://svnweb.freebsd.org/changeset/base/356331 Log: Merge commit c6b09bff5 from llvm git (by Luís Marques): [RISCV] Fix wrong CFI directives Summary: Removes CFI CFA directives that could incorrectly propagate beyond the basic block they were inteded for. Specifically it removes the epilogue CFI directives. See the branch_and_tail_call test for an example of the issue. Should fix the stack unwinding issues caused by the incorrect directives. Reviewers: asb, lenary, shiva0217 Reviewed By: lenary Tags: #llvm Differential Revision: https://reviews.llvm.org/D69723 This is a prerequisite for building and linking hard- and soft-float riscv worlds with clang and lld. Requested by: jhb MFC after: 1 week X-MFC-With: r353358 Modified: head/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp Modified: head/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp ============================================================================== --- head/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp Fri Jan 3 20:11:40 2020 (r356330) +++ head/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp Fri Jan 3 20:19:17 2020 (r356331) @@ -205,7 +205,6 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction MachineFrameInfo &MFI = MF.getFrameInfo(); auto *RVFI = MF.getInfo<RISCVMachineFunctionInfo>(); DebugLoc DL = MBBI->getDebugLoc(); - const RISCVInstrInfo *TII = STI.getInstrInfo(); unsigned FPReg = getFPReg(STI); unsigned SPReg = getSPReg(STI); @@ -226,47 +225,8 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction MachineInstr::FrameDestroy); } - 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()) { - unsigned DestReg = I->getOperand(0).getReg(); - if (DestReg == FPReg) { - // If there is frame pointer, after restoring $fp registers, we - // need adjust CFA to ($sp - FPOffset). - // Emit ".cfi_def_cfa $sp, -FPOffset" - unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::createDefCfa( - nullptr, RI->getDwarfRegNum(SPReg, true), -FPOffset)); - BuildMI(MBB, std::next(I), DL, - TII->get(TargetOpcode::CFI_INSTRUCTION)) - .addCFIIndex(CFIIndex); - break; - } - } - } - } - - // Add CFI directives for callee-saved registers. - const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo(); - // Iterate over list of callee-saved registers and emit .cfi_restore - // directives. - for (const auto &Entry : CSI) { - unsigned 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); - } - // 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,
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