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author | Francis Visoiu Mistrih <fvisoiumistrih@apple.com> | 2017-07-20 20:17:17 +0000 |
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committer | Francis Visoiu Mistrih <fvisoiumistrih@apple.com> | 2017-07-20 20:17:17 +0000 |
commit | 631f6b888c50276450fee8b9ef129f37f83fc5a1 (patch) | |
tree | c23dbd262b5250fc0ef516c3e9e2ef8e858c4985 /llvm/lib/CodeGen/PrologEpilogInserter.cpp | |
parent | d1b731d57b8e8d01a8b3c9bed95995b8bd6f8a88 (diff) | |
download | llvm-631f6b888c50276450fee8b9ef129f37f83fc5a1.zip llvm-631f6b888c50276450fee8b9ef129f37f83fc5a1.tar.gz llvm-631f6b888c50276450fee8b9ef129f37f83fc5a1.tar.bz2 |
[PEI] Separate saving and restoring CSRs into different functions. NFC
Split insertCSRSpillsAndRestores into insertCSRSaves + insertCSRRestores.
This is mostly useful for future shrink-wrapping improvements where we
want to save / restore a specific part of the CSRs in a specific block.
Differential Revision: https://reviews.llvm.org/D35644
llvm-svn: 308664
Diffstat (limited to 'llvm/lib/CodeGen/PrologEpilogInserter.cpp')
-rw-r--r-- | llvm/lib/CodeGen/PrologEpilogInserter.cpp | 117 |
1 files changed, 51 insertions, 66 deletions
diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp index 85f67c9..d6595d2 100644 --- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp +++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp @@ -466,76 +466,47 @@ static void updateLiveness(MachineFunction &MF) { } } -/// insertCSRSpillsAndRestores - Insert spill and restore code for -/// callee saved registers used in the function. -/// -static void insertCSRSpillsAndRestores(MachineFunction &Fn, - const MBBVector &SaveBlocks, - const MBBVector &RestoreBlocks) { - // Get callee saved register information. - MachineFrameInfo &MFI = Fn.getFrameInfo(); - const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo(); - - MFI.setCalleeSavedInfoValid(true); - - // Early exit if no callee saved registers are modified! - if (CSI.empty()) - return; - +/// Insert restore code for the callee-saved registers used in the function. +static void insertCSRSaves(MachineBasicBlock &SaveBlock, + ArrayRef<CalleeSavedInfo> CSI) { + MachineFunction &Fn = *SaveBlock.getParent(); const TargetInstrInfo &TII = *Fn.getSubtarget().getInstrInfo(); const TargetFrameLowering *TFI = Fn.getSubtarget().getFrameLowering(); const TargetRegisterInfo *TRI = Fn.getSubtarget().getRegisterInfo(); - MachineBasicBlock::iterator I; - - // Spill using target interface. - for (MachineBasicBlock *SaveBlock : SaveBlocks) { - I = SaveBlock->begin(); - if (!TFI->spillCalleeSavedRegisters(*SaveBlock, I, CSI, TRI)) { - for (unsigned i = 0, e = CSI.size(); i != e; ++i) { - // Insert the spill to the stack frame. - unsigned Reg = CSI[i].getReg(); - const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); - TII.storeRegToStackSlot(*SaveBlock, I, Reg, true, CSI[i].getFrameIdx(), - RC, TRI); - } + + MachineBasicBlock::iterator I = SaveBlock.begin(); + if (!TFI->spillCalleeSavedRegisters(SaveBlock, I, CSI, TRI)) { + for (const CalleeSavedInfo &CS : CSI) { + // Insert the spill to the stack frame. + unsigned Reg = CS.getReg(); + const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); + TII.storeRegToStackSlot(SaveBlock, I, Reg, true, CS.getFrameIdx(), RC, + TRI); } - // Update the live-in information of all the blocks up to the save point. - updateLiveness(Fn); } +} - // Restore using target interface. - for (MachineBasicBlock *MBB : RestoreBlocks) { - I = MBB->end(); - - // Skip over all terminator instructions, which are part of the return - // sequence. - MachineBasicBlock::iterator I2 = I; - while (I2 != MBB->begin() && (--I2)->isTerminator()) - I = I2; - - bool AtStart = I == MBB->begin(); - MachineBasicBlock::iterator BeforeI = I; - if (!AtStart) - --BeforeI; - - // Restore all registers immediately before the return and any - // terminators that precede it. - if (!TFI->restoreCalleeSavedRegisters(*MBB, I, CSI, TRI)) { - for (unsigned i = 0, e = CSI.size(); i != e; ++i) { - unsigned Reg = CSI[i].getReg(); - const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); - TII.loadRegFromStackSlot(*MBB, I, Reg, CSI[i].getFrameIdx(), RC, TRI); - assert(I != MBB->begin() && - "loadRegFromStackSlot didn't insert any code!"); - // Insert in reverse order. loadRegFromStackSlot can insert - // multiple instructions. - if (AtStart) - I = MBB->begin(); - else { - I = BeforeI; - ++I; - } - } +/// Insert restore code for the callee-saved registers used in the function. +static void insertCSRRestores(MachineBasicBlock &RestoreBlock, + ArrayRef<CalleeSavedInfo> CSI) { + MachineFunction &Fn = *RestoreBlock.getParent(); + const TargetInstrInfo &TII = *Fn.getSubtarget().getInstrInfo(); + const TargetFrameLowering *TFI = Fn.getSubtarget().getFrameLowering(); + const TargetRegisterInfo *TRI = Fn.getSubtarget().getRegisterInfo(); + + // Restore all registers immediately before the return and any + // terminators that precede it. + MachineBasicBlock::iterator I = RestoreBlock.getFirstTerminator(); + + if (!TFI->restoreCalleeSavedRegisters(RestoreBlock, I, CSI, TRI)) { + for (const CalleeSavedInfo &CI : reverse(CSI)) { + unsigned Reg = CI.getReg(); + const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); + TII.loadRegFromStackSlot(RestoreBlock, I, Reg, CI.getFrameIdx(), RC, TRI); + assert(I != RestoreBlock.begin() && + "loadRegFromStackSlot didn't insert any code!"); + // Insert in reverse order. loadRegFromStackSlot can insert + // multiple instructions. } } } @@ -547,6 +518,8 @@ static void doSpillCalleeSavedRegs(MachineFunction &Fn, RegScavenger *RS, const MBBVector &RestoreBlocks) { const Function *F = Fn.getFunction(); const TargetFrameLowering *TFI = Fn.getSubtarget().getFrameLowering(); + MachineFrameInfo &MFI = Fn.getFrameInfo(); + ArrayRef<CalleeSavedInfo> CSI = MFI.getCalleeSavedInfo(); MinCSFrameIndex = std::numeric_limits<unsigned>::max(); MaxCSFrameIndex = 0; @@ -558,8 +531,20 @@ static void doSpillCalleeSavedRegs(MachineFunction &Fn, RegScavenger *RS, assignCalleeSavedSpillSlots(Fn, SavedRegs, MinCSFrameIndex, MaxCSFrameIndex); // Add the code to save and restore the callee saved registers. - if (!F->hasFnAttribute(Attribute::Naked)) - insertCSRSpillsAndRestores(Fn, SaveBlocks, RestoreBlocks); + if (!F->hasFnAttribute(Attribute::Naked)) { + MFI.setCalleeSavedInfoValid(true); + + if (!CSI.empty()) { + for (MachineBasicBlock *SaveBlock : SaveBlocks) { + insertCSRSaves(*SaveBlock, CSI); + // Update the live-in information of all the blocks up to the save + // point. + updateLiveness(Fn); + } + for (MachineBasicBlock *RestoreBlock : RestoreBlocks) + insertCSRRestores(*RestoreBlock, CSI); + } + } } /// AdjustStackOffset - Helper function used to adjust the stack frame offset. |