[llvm-commits] [llvm] r167313 - in /llvm/trunk/lib/Target/Mips: MipsFrameLowering.cpp MipsFrameLowering.h

[Akira Hatanaka]

Author: ahatanak
Date: Fri Nov  2 16:10:22 2012
New Revision: 167313

URL: http://llvm.org/viewvc/llvm-project?rev=167313&view=rev
Log:
[mips] Add function MipsFrameLowering::estimateStackSize.

This function estimates stack size and will be called before
PrologEpilogInserter scans the callee-saved registers.


Modified:
    llvm/trunk/lib/Target/Mips/MipsFrameLowering.cpp
    llvm/trunk/lib/Target/Mips/MipsFrameLowering.h

Modified: llvm/trunk/lib/Target/Mips/MipsFrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsFrameLowering.cpp?rev=167313&r1=167312&r2=167313&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/MipsFrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/Mips/MipsFrameLowering.cpp Fri Nov  2 16:10:22 2012
@@ -98,3 +98,37 @@
   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());
+}

Modified: llvm/trunk/lib/Target/Mips/MipsFrameLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsFrameLowering.h?rev=167313&r1=167312&r2=167313&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/MipsFrameLowering.h (original)
+++ llvm/trunk/lib/Target/Mips/MipsFrameLowering.h Fri Nov  2 16:10:22 2012
@@ -34,6 +34,9 @@
                                          const MipsSubtarget &ST);
 
   bool hasFP(const MachineFunction &MF) const;
+
+protected:
+  uint64_t estimateStackSize(const MachineFunction &MF) const;
 };
 
 /// Create MipsInstrInfo objects.