[llvm] r308554 - [PEI] Separate saving and restoring CSRs into different functions. NFC
Francis Visoiu Mistrih via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 19 16:47:31 PDT 2017
Author: thegameg
Date: Wed Jul 19 16:47:31 2017
New Revision: 308554
URL: http://llvm.org/viewvc/llvm-project?rev=308554&view=rev
Log:
[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
Modified:
llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp
Modified: llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp?rev=308554&r1=308553&r2=308554&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp (original)
+++ llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp Wed Jul 19 16:47:31 2017
@@ -459,76 +459,47 @@ static void updateLiveness(MachineFuncti
}
}
-/// 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.
}
}
}
@@ -540,6 +511,8 @@ static void doSpillCalleeSavedRegs(Machi
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;
@@ -551,8 +524,20 @@ static void doSpillCalleeSavedRegs(Machi
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.
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