Replace PROLOG_LABEL with a new CFI_INSTRUCTION.
The old system was fairly convoluted:
* A temporary label was created.
* A single PROLOG_LABEL was created with it.
* A few MCCFIInstructions were created with the same label.
The semantics were that the cfi instructions were mapped to the PROLOG_LABEL
via the temporary label. The output position was that of the PROLOG_LABEL.
The temporary label itself was used only for doing the mapping.
The new CFI_INSTRUCTION has a 1:1 mapping to MCCFIInstructions and points to
one by holding an index into the CFI instructions of this function.
I did consider removing MMI.getFrameInstructions completelly and having
CFI_INSTRUCTION own a MCCFIInstruction, but MCCFIInstructions have non
trivial constructors and destructors and are somewhat big, so the this setup
is probably better.
The net result is that we don't create temporary labels that are never used.
llvm-svn: 203204
diff --git a/llvm/lib/Target/X86/X86CodeEmitter.cpp b/llvm/lib/Target/X86/X86CodeEmitter.cpp
index 82ba599..8883833 100644
--- a/llvm/lib/Target/X86/X86CodeEmitter.cpp
+++ b/llvm/lib/Target/X86/X86CodeEmitter.cpp
@@ -1115,7 +1115,8 @@
if (MI.getOperand(0).getSymbolName()[0])
report_fatal_error("JIT does not support inline asm!");
break;
- case TargetOpcode::PROLOG_LABEL:
+ case TargetOpcode::CFI_INSTRUCTION:
+ break;
case TargetOpcode::GC_LABEL:
case TargetOpcode::EH_LABEL:
MCE.emitLabel(MI.getOperand(0).getMCSymbol());
diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index 898074c..0bdabb2 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -304,12 +304,14 @@
return false;
}
-void X86FrameLowering::emitCalleeSavedFrameMoves(MachineFunction &MF,
- MCSymbol *Label,
- unsigned FramePtr) const {
+void X86FrameLowering::emitCalleeSavedFrameMoves(
+ MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, DebugLoc DL,
+ unsigned FramePtr) const {
+ MachineFunction &MF = *MBB.getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
+ const X86InstrInfo &TII = *TM.getInstrInfo();
// Add callee saved registers to move list.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
@@ -363,7 +365,9 @@
continue;
unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
- MMI.addFrameInst(MCCFIInstruction::createOffset(Label, DwarfReg, Offset));
+ unsigned CFIIndex =
+ MMI.addFrameInst(MCCFIInstruction::createOffset(0, DwarfReg, Offset));
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION)).addCFIIndex(CFIIndex);
}
}
@@ -503,19 +507,19 @@
if (needsFrameMoves) {
// Mark the place where EBP/RBP was saved.
- MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL))
- .addSym(FrameLabel);
-
// Define the current CFA rule to use the provided offset.
assert(StackSize);
- MMI.addFrameInst(
- MCCFIInstruction::createDefCfaOffset(FrameLabel, 2 * stackGrowth));
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(0, 2 * stackGrowth));
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
// Change the rule for the FramePtr to be an "offset" rule.
unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(FramePtr, true);
- MMI.addFrameInst(MCCFIInstruction::createOffset(FrameLabel, DwarfFramePtr,
- 2 * stackGrowth));
+ CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createOffset(0, DwarfFramePtr, 2 * stackGrowth));
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
// Update EBP with the new base value.
@@ -526,14 +530,12 @@
if (needsFrameMoves) {
// Mark effective beginning of when frame pointer becomes valid.
- MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL))
- .addSym(FrameLabel);
-
// Define the current CFA to use the EBP/RBP register.
unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(FramePtr, true);
- MMI.addFrameInst(
- MCCFIInstruction::createDefCfaRegister(FrameLabel, DwarfFramePtr));
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaRegister(0, DwarfFramePtr));
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
// Mark the FramePtr as live-in in every block except the entry.
@@ -557,13 +559,12 @@
if (!HasFP && needsFrameMoves) {
// Mark callee-saved push instruction.
- MCSymbol *Label = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(Label);
-
// Define the current CFA rule to use the provided offset.
assert(StackSize);
- MMI.addFrameInst(
- MCCFIInstruction::createDefCfaOffset(Label, StackOffset));
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, StackOffset));
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
StackOffset += stackGrowth;
}
}
@@ -692,20 +693,19 @@
if (( (!HasFP && NumBytes) || PushedRegs) && needsFrameMoves) {
// Mark end of stack pointer adjustment.
- MCSymbol *Label = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL))
- .addSym(Label);
-
if (!HasFP && NumBytes) {
// Define the current CFA rule to use the provided offset.
assert(StackSize);
- MMI.addFrameInst(MCCFIInstruction::createDefCfaOffset(
- Label, -StackSize + stackGrowth));
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(0, -StackSize + stackGrowth));
+
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
// Emit DWARF info specifying the offsets of the callee-saved registers.
if (PushedRegs)
- emitCalleeSavedFrameMoves(MF, Label, HasFP ? FramePtr : StackPtr);
+ emitCalleeSavedFrameMoves(MBB, MBBI, DL, HasFP ? FramePtr : StackPtr);
}
}
diff --git a/llvm/lib/Target/X86/X86FrameLowering.h b/llvm/lib/Target/X86/X86FrameLowering.h
index 3d3b011..cd50cce 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.h
+++ b/llvm/lib/Target/X86/X86FrameLowering.h
@@ -34,7 +34,8 @@
TM(tm), STI(sti) {
}
- void emitCalleeSavedFrameMoves(MachineFunction &MF, MCSymbol *Label,
+ void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI, DebugLoc DL,
unsigned FramePtr) const;
/// emitProlog/emitEpilog - These methods insert prolog and epilog code into