From 265f191b57a4e359bc44a51602c9d2a4ee6af96b Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Fri, 2 Nov 2012 21:10:22 +0000 Subject: [mips] Add function MipsFrameLowering::estimateStackSize. This function estimates stack size and will be called before PrologEpilogInserter scans the callee-saved registers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167313 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/Mips/MipsFrameLowering.cpp | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'lib/Target/Mips/MipsFrameLowering.cpp') diff --git a/lib/Target/Mips/MipsFrameLowering.cpp b/lib/Target/Mips/MipsFrameLowering.cpp index 6dd251c054..2cad2a6264 100644 --- a/lib/Target/Mips/MipsFrameLowering.cpp +++ b/lib/Target/Mips/MipsFrameLowering.cpp @@ -98,3 +98,37 @@ bool MipsFrameLowering::hasFP(const MachineFunction &MF) const { return MF.getTarget().Options.DisableFramePointerElim(MF) || MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken(); } + +uint64_t MipsFrameLowering::estimateStackSize(const MachineFunction &MF) const { + const MachineFrameInfo *MFI = MF.getFrameInfo(); + const TargetRegisterInfo &TRI = *MF.getTarget().getRegisterInfo(); + + int64_t Offset = 0; + + // Iterate over fixed sized objects. + for (int I = MFI->getObjectIndexBegin(); I != 0; ++I) + Offset = std::max(Offset, -MFI->getObjectOffset(I)); + + // Conservatively assume all callee-saved registers will be saved. + for (const uint16_t *R = TRI.getCalleeSavedRegs(&MF); *R; ++R) { + unsigned Size = TRI.getMinimalPhysRegClass(*R)->getSize(); + Offset = RoundUpToAlignment(Offset + Size, Size); + } + + unsigned MaxAlign = MFI->getMaxAlignment(); + + // Check that MaxAlign is not zero if there is a stack object that is not a + // callee-saved spill. + assert(!MFI->getObjectIndexEnd() || MaxAlign); + + // Iterate over other objects. + for (unsigned I = 0, E = MFI->getObjectIndexEnd(); I != E; ++I) + Offset = RoundUpToAlignment(Offset + MFI->getObjectSize(I), MaxAlign); + + // Call frame. + if (MFI->adjustsStack() && hasReservedCallFrame(MF)) + Offset = RoundUpToAlignment(Offset + MFI->getMaxCallFrameSize(), + std::max(MaxAlign, getStackAlignment())); + + return RoundUpToAlignment(Offset, getStackAlignment()); +} -- cgit v1.2.3