[AArch64] Clean up callee-save CFI emission. NFC.
Summary:
Avoid special case for FP, LR CFI emission and just allow general
AArch64FrameLowering::emitCalleeSavedFrameMoves() to handle them. Also,
stop recalculating the stack offsets in emitCalleeSavedFrameMoves()
since we can just reuse the previously calculated offset stored in the
MachineFrameInfo.
Depends on D17000
Reviewers: t.p.northover, rengolin, mcrosier, jmolloy
Subscribers: aemerson, rengolin, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D17004
llvm-svn: 261885
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 2473054..75a8b15 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -202,8 +202,7 @@
}
void AArch64FrameLowering::emitCalleeSavedFrameMoves(
- MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
- unsigned FramePtr) const {
+ MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI) const {
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
@@ -216,34 +215,13 @@
if (CSI.empty())
return;
- const DataLayout &TD = MF.getDataLayout();
- bool HasFP = hasFP(MF);
-
- // Calculate amount of bytes used for return address storing.
- int stackGrowth = -TD.getPointerSize(0);
-
- // Calculate offsets.
- int64_t saveAreaOffset = (HasFP ? 2 : 1) * stackGrowth;
- unsigned TotalSkipped = 0;
for (const auto &Info : CSI) {
unsigned Reg = Info.getReg();
- int64_t Offset = MFI->getObjectOffset(Info.getFrameIdx()) -
- getOffsetOfLocalArea() + saveAreaOffset;
-
- // Don't output a new CFI directive if we're re-saving the frame pointer or
- // link register. This happens when the PrologEpilogInserter has inserted an
- // extra "STP" of the frame pointer and link register -- the "emitPrologue"
- // method automatically generates the directives when frame pointers are
- // used. If we generate CFI directives for the extra "STP"s, the linker will
- // lose track of the correct values for the frame pointer and link register.
- if (HasFP && (FramePtr == Reg || Reg == AArch64::LR)) {
- TotalSkipped += stackGrowth;
- continue;
- }
-
+ int64_t Offset =
+ MFI->getObjectOffset(Info.getFrameIdx()) - getOffsetOfLocalArea();
unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
- unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
- nullptr, DwarfReg, Offset - TotalSkipped));
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createOffset(nullptr, DwarfReg, Offset));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
@@ -512,21 +490,6 @@
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
-
- // Record the location of the stored LR
- unsigned LR = RegInfo->getDwarfRegNum(AArch64::LR, true);
- CFIIndex = MMI.addFrameInst(
- MCCFIInstruction::createOffset(nullptr, LR, StackGrowth));
- BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
- .addCFIIndex(CFIIndex)
- .setMIFlags(MachineInstr::FrameSetup);
-
- // Record the location of the stored FP
- CFIIndex = MMI.addFrameInst(
- MCCFIInstruction::createOffset(nullptr, Reg, 2 * StackGrowth));
- BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
- .addCFIIndex(CFIIndex)
- .setMIFlags(MachineInstr::FrameSetup);
} else {
// Encode the stack size of the leaf function.
unsigned CFIIndex = MMI.addFrameInst(
@@ -536,8 +499,9 @@
.setMIFlags(MachineInstr::FrameSetup);
}
- // Now emit the moves for whatever callee saved regs we have.
- emitCalleeSavedFrameMoves(MBB, MBBI, FramePtr);
+ // Now emit the moves for whatever callee saved regs we have (including FP,
+ // LR if those are saved).
+ emitCalleeSavedFrameMoves(MBB, MBBI);
}
}