From b5dd9452b46b17f49c4afcc00c06c4bfcb4fdc87 Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Tue, 1 Jul 2014 00:42:47 +0000 Subject: Fix .seh_stackalloc 0 seh_stackalloc 0 is not representable in Win64 SEH info, so emitting it is a bug. Reviewers: rnk Differential Revision: http://reviews.llvm.org/D4334 Patch by Vadim Chugunov! llvm-svn: 212081 --- llvm/lib/MC/MCStreamer.cpp | 2 ++ llvm/lib/Target/X86/X86FrameLowering.cpp | 11 +++++++---- 2 files changed, 9 insertions(+), 4 deletions(-) (limited to 'llvm/lib') diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp index eca1ed7d7fe..bdcdb970cc1 100644 --- a/llvm/lib/MC/MCStreamer.cpp +++ b/llvm/lib/MC/MCStreamer.cpp @@ -515,6 +515,8 @@ void MCStreamer::EmitWinCFISetFrame(unsigned Register, unsigned Offset) { void MCStreamer::EmitWinCFIAllocStack(unsigned Size) { EnsureValidW64UnwindInfo(); + if (Size == 0) + report_fatal_error("Allocation size must be non-zero!"); if (Size & 7) report_fatal_error("Misaligned stack allocation!"); MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo; diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp index 1544549e5e9..8c029a8c22d 100644 --- a/llvm/lib/Target/X86/X86FrameLowering.cpp +++ b/llvm/lib/Target/X86/X86FrameLowering.cpp @@ -751,10 +751,13 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const { SEHFrameOffset += SEHFrameOffset % 16; // ensure alignmant // This only needs to account for XMM spill slots, GPR slots - // are covered by .seh_pushreg's emitted above. - BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_StackAlloc)) - .addImm(SEHFrameOffset - X86FI->getCalleeSavedFrameSize()) - .setMIFlag(MachineInstr::FrameSetup); + // are covered by the .seh_pushreg's emitted above. + unsigned Size = SEHFrameOffset - X86FI->getCalleeSavedFrameSize(); + if (Size) { + BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_StackAlloc)) + .addImm(Size) + .setMIFlag(MachineInstr::FrameSetup); + } BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_SetFrame)) .addImm(FramePtr) -- cgit v1.2.3