//
//===----------------------------------------------------------------------===//
-#ifndef X86_FRAMELOWERING_H
-#define X86_FRAMELOWERING_H
+#ifndef LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
+#define LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
-#include "X86Subtarget.h"
-#include "llvm/MC/MCDwarf.h"
#include "llvm/Target/TargetFrameLowering.h"
namespace llvm {
-namespace CU {
+class MachineInstrBuilder;
+class MCCFIInstruction;
+class X86Subtarget;
+class X86RegisterInfo;
- /// Compact unwind encoding values.
- enum CompactUnwindEncodings {
- /// [RE]BP based frame where [RE]BP is pused on the stack immediately after
- /// the return address, then [RE]SP is moved to [RE]BP.
- UNWIND_MODE_BP_FRAME = 0x01000000,
+class X86FrameLowering : public TargetFrameLowering {
+public:
+ X86FrameLowering(const X86Subtarget &STI, unsigned StackAlignOverride);
- /// A frameless function with a small constant stack size.
- UNWIND_MODE_STACK_IMMD = 0x02000000,
+ // Cached subtarget predicates.
- /// A frameless function with a large constant stack size.
- UNWIND_MODE_STACK_IND = 0x03000000,
+ const X86Subtarget &STI;
+ const TargetInstrInfo &TII;
+ const X86RegisterInfo *TRI;
- /// No compact unwind encoding is available.
- UNWIND_MODE_DWARF = 0x04000000,
+ unsigned SlotSize;
- /// Mask for encoding the frame registers.
- UNWIND_BP_FRAME_REGISTERS = 0x00007FFF,
+ /// Is64Bit implies that x86_64 instructions are available.
+ bool Is64Bit;
- /// Mask for encoding the frameless registers.
- UNWIND_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF
- };
+ bool IsLP64;
-} // end CU namespace
+ /// True if the 64-bit frame or stack pointer should be used. True for most
+ /// 64-bit targets with the exception of x32. If this is false, 32-bit
+ /// instruction operands should be used to manipulate StackPtr and FramePtr.
+ bool Uses64BitFramePtr;
-class MCSymbol;
-class X86TargetMachine;
+ unsigned StackPtr;
-class X86FrameLowering : public TargetFrameLowering {
- const X86TargetMachine &TM;
- const X86Subtarget &STI;
-public:
- explicit X86FrameLowering(const X86TargetMachine &tm, const X86Subtarget &sti)
- : TargetFrameLowering(StackGrowsDown,
- sti.getStackAlignment(),
- (sti.is64Bit() ? -8 : -4)),
- TM(tm), STI(sti) {
- }
+ /// Emit a call to the target's stack probe function. This is required for all
+ /// large stack allocations on Windows. The caller is required to materialize
+ /// the number of bytes to probe in RAX/EAX.
+ void emitStackProbeCall(MachineFunction &MF, MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI, DebugLoc DL) const;
- void emitCalleeSavedFrameMoves(MachineFunction &MF, MCSymbol *Label,
- unsigned FramePtr) const;
+ void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI,
+ DebugLoc DL) const;
/// emitProlog/emitEpilog - These methods insert prolog and epilog code into
/// the function.
- void emitPrologue(MachineFunction &MF) const;
- void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const;
+ void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+ void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
- void adjustForSegmentedStacks(MachineFunction &MF) const;
+ void adjustForSegmentedStacks(MachineFunction &MF,
+ MachineBasicBlock &PrologueMBB) const override;
- void adjustForHiPEPrologue(MachineFunction &MF) const;
+ void adjustForHiPEPrologue(MachineFunction &MF,
+ MachineBasicBlock &PrologueMBB) const override;
- void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS = NULL) const;
+ void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
+ RegScavenger *RS = nullptr) const override;
+
+ bool
+ assignCalleeSavedSpillSlots(MachineFunction &MF,
+ const TargetRegisterInfo *TRI,
+ std::vector<CalleeSavedInfo> &CSI) const override;
bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
- const TargetRegisterInfo *TRI) const;
+ const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
- const TargetRegisterInfo *TRI) const;
+ MachineBasicBlock::iterator MI,
+ const std::vector<CalleeSavedInfo> &CSI,
+ const TargetRegisterInfo *TRI) const override;
- bool hasFP(const MachineFunction &MF) const;
- bool hasReservedCallFrame(const MachineFunction &MF) const;
+ bool hasFP(const MachineFunction &MF) const override;
+ bool hasReservedCallFrame(const MachineFunction &MF) const override;
+ bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
+ bool needsFrameIndexResolution(const MachineFunction &MF) const override;
- int getFrameIndexOffset(const MachineFunction &MF, int FI) const;
int getFrameIndexReference(const MachineFunction &MF, int FI,
- unsigned &FrameReg) const;
- uint32_t getCompactUnwindEncoding(MachineFunction &MF) const;
+ unsigned &FrameReg) const override;
+
+ int getFrameIndexReferenceFromSP(const MachineFunction &MF, int FI,
+ unsigned &FrameReg) const override;
void eliminateCallFramePseudoInstr(MachineFunction &MF,
- MachineBasicBlock &MBB,
- MachineBasicBlock::iterator MI) const;
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI) const override;
+
+ unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
+
+ /// Check the instruction before/after the passed instruction. If
+ /// it is an ADD/SUB/LEA instruction it is deleted argument and the
+ /// stack adjustment is returned as a positive value for ADD/LEA and
+ /// a negative for SUB.
+ int mergeSPUpdates(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
+ bool doMergeWithPrevious) const;
+
+ /// Emit a series of instructions to increment / decrement the stack
+ /// pointer by a constant value.
+ void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
+ int64_t NumBytes, bool InEpilogue) const;
+
+ /// Check that LEA can be used on SP in an epilogue sequence for \p MF.
+ bool canUseLEAForSPInEpilogue(const MachineFunction &MF) const;
+
+ /// Check whether or not the given \p MBB can be used as a epilogue
+ /// for the target.
+ /// The epilogue will be inserted before the first terminator of that block.
+ /// This method is used by the shrink-wrapping pass to decide if
+ /// \p MBB will be correctly handled by the target.
+ bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override;
+
+private:
+ uint64_t calculateMaxStackAlign(const MachineFunction &MF) const;
+
+ /// Wraps up getting a CFI index and building a MachineInstr for it.
+ void BuildCFI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
+ DebugLoc DL, MCCFIInstruction CFIInst) const;
+
+ /// Aligns the stack pointer by ANDing it with -MaxAlign.
+ void BuildStackAlignAND(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI, DebugLoc DL,
+ uint64_t MaxAlign) const;
+
+ /// Make small positive stack adjustments using POPs.
+ bool adjustStackWithPops(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI, DebugLoc DL,
+ int Offset) const;
+
+ /// Adjusts the stack pointer using LEA, SUB, or ADD.
+ MachineInstrBuilder BuildStackAdjustment(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI,
+ DebugLoc DL, int64_t Offset,
+ bool InEpilogue) const;
+
+ /// Sets up EBP and optionally ESI based on the incoming EBP value. Only
+ /// needed for 32-bit. Used in funclet prologues and at catchret destinations.
+ MachineBasicBlock::iterator
+ restoreWin32EHStackPointers(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI, DebugLoc DL,
+ bool RestoreSP = false) const;
+
+ unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const;
};
} // End llvm namespace