diff options
| -rw-r--r-- | lib/Target/X86/X86RegisterInfo.cpp | 136 |
1 files changed, 81 insertions, 55 deletions
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp index 757451635b..77246ed160 100644 --- a/lib/Target/X86/X86RegisterInfo.cpp +++ b/lib/Target/X86/X86RegisterInfo.cpp @@ -677,9 +677,9 @@ void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset; MachineInstr *MI = BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr) - .addReg(StackPtr).addImm(ThisVal); - // The EFLAGS implicit def is dead. - MI->getOperand(3).setIsDead(); + .addReg(StackPtr) + .addImm(ThisVal); + MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead. Offset -= ThisVal; } } @@ -712,6 +712,7 @@ static void mergeSPUpdatesDown(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, unsigned StackPtr, uint64_t *NumBytes = NULL) { + // FIXME: THIS ISN'T RUN!!! return; if (MBBI == MBB.end()) return; @@ -840,50 +841,47 @@ void X86RegisterInfo::emitCalleeSavedFrameMoves(MachineFunction &MF, } } +/// emitPrologue - Push callee-saved registers onto the stack, which +/// automatically adjust the stack pointer. Adjust the stack pointer to allocate +/// space for local variables. Also emit labels used by the exception handler to +/// generate the exception handling frames. void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { - MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB + MachineBasicBlock &MBB = MF.front(); // Prologue goes in entry BB. + MachineBasicBlock::iterator MBBI = MBB.begin(); MachineFrameInfo *MFI = MF.getFrameInfo(); - const Function* Fn = MF.getFunction(); - const X86Subtarget* Subtarget = &MF.getTarget().getSubtarget<X86Subtarget>(); + const Function *Fn = MF.getFunction(); + const X86Subtarget *Subtarget = &MF.getTarget().getSubtarget<X86Subtarget>(); MachineModuleInfo *MMI = MFI->getMachineModuleInfo(); X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>(); - MachineBasicBlock::iterator MBBI = MBB.begin(); bool needsFrameMoves = (MMI && MMI->hasDebugInfo()) || - !Fn->doesNotThrow() || - UnwindTablesMandatory; + !Fn->doesNotThrow() || UnwindTablesMandatory; + uint64_t MaxAlign = MFI->getMaxAlignment(); // Desired stack alignment. + uint64_t StackSize = MFI->getStackSize(); // Number of bytes to allocate. bool HasFP = hasFP(MF); DebugLoc DL; - // Get the number of bytes to allocate from the FrameInfo. - uint64_t StackSize = MFI->getStackSize(); - - // Get desired stack alignment - uint64_t MaxAlign = MFI->getMaxAlignment(); - // Add RETADDR move area to callee saved frame size. int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta(); if (TailCallReturnAddrDelta < 0) X86FI->setCalleeSavedFrameSize( - X86FI->getCalleeSavedFrameSize() +(-TailCallReturnAddrDelta)); + X86FI->getCalleeSavedFrameSize() - TailCallReturnAddrDelta); // If this is x86-64 and the Red Zone is not disabled, if we are a leaf // function, and use up to 128 bytes of stack space, don't have a frame // pointer, calls, or dynamic alloca then we do not need to adjust the // stack pointer (we fit in the Red Zone). - bool DisableRedZone = Fn->hasFnAttr(Attribute::NoRedZone); - if (Is64Bit && !DisableRedZone && + if (Is64Bit && !Fn->hasFnAttr(Attribute::NoRedZone) && !needsStackRealignment(MF) && !MFI->hasVarSizedObjects() && // No dynamic alloca. !MFI->hasCalls() && // No calls. !Subtarget->isTargetWin64()) { // Win64 has no Red Zone uint64_t MinSize = X86FI->getCalleeSavedFrameSize(); if (HasFP) MinSize += SlotSize; - StackSize = std::max(MinSize, - StackSize > 128 ? StackSize - 128 : 0); + StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0); MFI->setStackSize(StackSize); } else if (Subtarget->isTargetWin64()) { // We need to always allocate 32 bytes as register spill area. - // FIXME: we might reuse these 32 bytes for leaf functions. + // FIXME: We might reuse these 32 bytes for leaf functions. StackSize += 32; MFI->setStackSize(StackSize); } @@ -894,25 +892,39 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { if (TailCallReturnAddrDelta < 0) { MachineInstr *MI = BuildMI(MBB, MBBI, DL, TII.get(Is64Bit? X86::SUB64ri32 : X86::SUB32ri), - StackPtr).addReg(StackPtr).addImm(-TailCallReturnAddrDelta); - // The EFLAGS implicit def is dead. - MI->getOperand(3).setIsDead(); + StackPtr) + .addReg(StackPtr) + .addImm(-TailCallReturnAddrDelta); + MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead. } - // uint64_t StackSize = MFI->getStackSize(); + // Mapping for machine moves: + // + // DST: VirtualFP AND + // SRC: VirtualFP => DW_CFA_def_cfa_offset + // ELSE => DW_CFA_def_cfa + // + // SRC: VirtualFP AND + // DST: Register => DW_CFA_def_cfa_register + // + // ELSE + // OFFSET < 0 => DW_CFA_offset_extended_sf + // REG < 64 => DW_CFA_offset + Reg + // ELSE => DW_CFA_offset_extended + std::vector<MachineMove> &Moves = MMI->getFrameMoves(); const TargetData *TD = MF.getTarget().getTargetData(); + uint64_t NumBytes = 0; int stackGrowth = (MF.getTarget().getFrameInfo()->getStackGrowthDirection() == TargetFrameInfo::StackGrowsUp ? - TD->getPointerSize() : -TD->getPointerSize()); + TD->getPointerSize() : -TD->getPointerSize()); - uint64_t NumBytes = 0; if (HasFP) { - // Calculate required stack adjustment + // Calculate required stack adjustment. uint64_t FrameSize = StackSize - SlotSize; if (needsStackRealignment(MF)) - FrameSize = (FrameSize + MaxAlign - 1)/MaxAlign*MaxAlign; + FrameSize = (FrameSize + MaxAlign - 1) / MaxAlign * MaxAlign; NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize(); @@ -921,12 +933,12 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { // Update the frame offset adjustment. MFI->setOffsetAdjustment(-NumBytes); - // Save EBP/RBP into the appropriate stack slot... + // Save EBP/RBP into the appropriate stack slot. BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r)) .addReg(FramePtr, RegState::Kill); if (needsFrameMoves) { - // Mark effective beginning of when frame pointer becomes valid. + // Mark the place where EBP/RBP was saved. unsigned FrameLabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(FrameLabelId); @@ -934,8 +946,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { if (StackSize) { MachineLocation SPDst(MachineLocation::VirtualFP); MachineLocation SPSrc(MachineLocation::VirtualFP, - HasFP ? 2 * stackGrowth : - -StackSize + stackGrowth); + 2 * stackGrowth); Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc)); } else { // FIXME: Verify & implement for FP @@ -945,7 +956,8 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { } // Change the rule for the FramePtr to be an "offset" rule. - MachineLocation FPDst(MachineLocation::VirtualFP, 2 * stackGrowth); + MachineLocation FPDst(MachineLocation::VirtualFP, + 2 * stackGrowth); MachineLocation FPSrc(FramePtr); Moves.push_back(MachineMove(FrameLabelId, FPDst, FPSrc)); } @@ -956,6 +968,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { .addReg(StackPtr); if (needsFrameMoves) { + // Mark effective beginning of when frame pointer becomes valid. unsigned FrameLabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(FrameLabelId); @@ -985,21 +998,28 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { } // Skip the callee-saved push instructions. - bool RegsSaved = false; + bool PushedRegs = false; + int StackOffset = 2 * stackGrowth; + while (MBBI != MBB.end() && (MBBI->getOpcode() == X86::PUSH32r || MBBI->getOpcode() == X86::PUSH64r)) { - RegsSaved = true; + PushedRegs = true; ++MBBI; - } - if (RegsSaved && needsFrameMoves) { - // Mark end of callee-saved push instructions. - unsigned LabelId = MMI->NextLabelID(); - BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(LabelId); + if (!HasFP && needsFrameMoves) { + // Mark callee-saved push instruction. + unsigned LabelId = MMI->NextLabelID(); + BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(LabelId); - // Emit DWARF info specifying the offsets of the callee-saved registers. - emitCalleeSavedFrameMoves(MF, LabelId, HasFP ? FramePtr : StackPtr); + // Define the current CFA rule to use the provided offset. + unsigned Ptr = StackSize ? + MachineLocation::VirtualFP : StackPtr; + MachineLocation SPDst(Ptr); + MachineLocation SPSrc(Ptr, StackOffset); + Moves.push_back(MachineMove(LabelId, SPDst, SPSrc)); + StackOffset += stackGrowth; + } } if (MBBI != MBB.end()) @@ -1058,23 +1078,29 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII); } - if (!HasFP && needsFrameMoves) { + if (NumBytes && needsFrameMoves) { // Mark end of stack pointer adjustment. unsigned LabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(LabelId); - // Define the current CFA rule to use the provided offset. - if (StackSize) { - MachineLocation SPDst(MachineLocation::VirtualFP); - MachineLocation SPSrc(MachineLocation::VirtualFP, - -StackSize + stackGrowth); - Moves.push_back(MachineMove(LabelId, SPDst, SPSrc)); - } else { - // FIXME: Verify & implement for FP - MachineLocation SPDst(StackPtr); - MachineLocation SPSrc(StackPtr, stackGrowth); - Moves.push_back(MachineMove(LabelId, SPDst, SPSrc)); + if (!HasFP) { + // Define the current CFA rule to use the provided offset. + if (StackSize) { + MachineLocation SPDst(MachineLocation::VirtualFP); + MachineLocation SPSrc(MachineLocation::VirtualFP, + -StackSize + stackGrowth); + Moves.push_back(MachineMove(LabelId, SPDst, SPSrc)); + } else { + // FIXME: Verify & implement for FP + MachineLocation SPDst(StackPtr); + MachineLocation SPSrc(StackPtr, stackGrowth); + Moves.push_back(MachineMove(LabelId, SPDst, SPSrc)); + } } + + // Emit DWARF info specifying the offsets of the callee-saved registers. + if (PushedRegs) + emitCalleeSavedFrameMoves(MF, LabelId, HasFP ? FramePtr : StackPtr); } } |