|  | //===-- PPCFrameLowering.h - Define frame lowering for PowerPC --*- C++ -*-===// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is distributed under the University of Illinois Open Source | 
|  | // License. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #ifndef POWERPC_FRAMEINFO_H | 
|  | #define POWERPC_FRAMEINFO_H | 
|  |  | 
|  | #include "PPC.h" | 
|  | #include "PPCSubtarget.h" | 
|  | #include "llvm/Target/TargetFrameLowering.h" | 
|  | #include "llvm/Target/TargetMachine.h" | 
|  | #include "llvm/ADT/STLExtras.h" | 
|  |  | 
|  | namespace llvm { | 
|  | class PPCSubtarget; | 
|  |  | 
|  | class PPCFrameLowering: public TargetFrameLowering { | 
|  | const PPCSubtarget &Subtarget; | 
|  |  | 
|  | public: | 
|  | PPCFrameLowering(const PPCSubtarget &sti) | 
|  | : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 16, 0), | 
|  | Subtarget(sti) { | 
|  | } | 
|  |  | 
|  | void determineFrameLayout(MachineFunction &MF) 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; | 
|  |  | 
|  | bool hasFP(const MachineFunction &MF) const; | 
|  | bool needsFP(const MachineFunction &MF) const; | 
|  |  | 
|  | void processFunctionBeforeCalleeSavedScan(MachineFunction &MF, | 
|  | RegScavenger *RS = NULL) const; | 
|  | void processFunctionBeforeFrameFinalized(MachineFunction &MF) const; | 
|  |  | 
|  | /// targetHandlesStackFrameRounding - Returns true if the target is | 
|  | /// responsible for rounding up the stack frame (probably at emitPrologue | 
|  | /// time). | 
|  | bool targetHandlesStackFrameRounding() const { return true; } | 
|  |  | 
|  | /// getReturnSaveOffset - Return the previous frame offset to save the | 
|  | /// return address. | 
|  | static unsigned getReturnSaveOffset(bool isPPC64, bool isDarwinABI) { | 
|  | if (isDarwinABI) | 
|  | return isPPC64 ? 16 : 8; | 
|  | // SVR4 ABI: | 
|  | return isPPC64 ? 16 : 4; | 
|  | } | 
|  |  | 
|  | /// getFramePointerSaveOffset - Return the previous frame offset to save the | 
|  | /// frame pointer. | 
|  | static unsigned getFramePointerSaveOffset(bool isPPC64, bool isDarwinABI) { | 
|  | // For the Darwin ABI: | 
|  | // We cannot use the TOC save slot (offset +20) in the PowerPC linkage area | 
|  | // for saving the frame pointer (if needed.)  While the published ABI has | 
|  | // not used this slot since at least MacOSX 10.2, there is older code | 
|  | // around that does use it, and that needs to continue to work. | 
|  | if (isDarwinABI) | 
|  | return isPPC64 ? -8U : -4U; | 
|  |  | 
|  | // SVR4 ABI: First slot in the general register save area. | 
|  | return isPPC64 ? -8U : -4U; | 
|  | } | 
|  |  | 
|  | /// getLinkageSize - Return the size of the PowerPC ABI linkage area. | 
|  | /// | 
|  | static unsigned getLinkageSize(bool isPPC64, bool isDarwinABI) { | 
|  | if (isDarwinABI || isPPC64) | 
|  | return 6 * (isPPC64 ? 8 : 4); | 
|  |  | 
|  | // SVR4 ABI: | 
|  | return 8; | 
|  | } | 
|  |  | 
|  | /// getMinCallArgumentsSize - Return the size of the minium PowerPC ABI | 
|  | /// argument area. | 
|  | static unsigned getMinCallArgumentsSize(bool isPPC64, bool isDarwinABI) { | 
|  | // For the Darwin ABI / 64-bit SVR4 ABI: | 
|  | // The prolog code of the callee may store up to 8 GPR argument registers to | 
|  | // the stack, allowing va_start to index over them in memory if its varargs. | 
|  | // Because we cannot tell if this is needed on the caller side, we have to | 
|  | // conservatively assume that it is needed.  As such, make sure we have at | 
|  | // least enough stack space for the caller to store the 8 GPRs. | 
|  | if (isDarwinABI || isPPC64) | 
|  | return 8 * (isPPC64 ? 8 : 4); | 
|  |  | 
|  | // 32-bit SVR4 ABI: | 
|  | // There is no default stack allocated for the 8 first GPR arguments. | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /// getMinCallFrameSize - Return the minimum size a call frame can be using | 
|  | /// the PowerPC ABI. | 
|  | static unsigned getMinCallFrameSize(bool isPPC64, bool isDarwinABI) { | 
|  | // The call frame needs to be at least big enough for linkage and 8 args. | 
|  | return getLinkageSize(isPPC64, isDarwinABI) + | 
|  | getMinCallArgumentsSize(isPPC64, isDarwinABI); | 
|  | } | 
|  |  | 
|  | // With the SVR4 ABI, callee-saved registers have fixed offsets on the stack. | 
|  | const SpillSlot * | 
|  | getCalleeSavedSpillSlots(unsigned &NumEntries) const { | 
|  | if (Subtarget.isDarwinABI()) { | 
|  | NumEntries = 1; | 
|  | if (Subtarget.isPPC64()) { | 
|  | static const SpillSlot darwin64Offsets = {PPC::X31, -8}; | 
|  | return &darwin64Offsets; | 
|  | } else { | 
|  | static const SpillSlot darwinOffsets = {PPC::R31, -4}; | 
|  | return &darwinOffsets; | 
|  | } | 
|  | } | 
|  |  | 
|  | // Early exit if not using the SVR4 ABI. | 
|  | if (!Subtarget.isSVR4ABI()) { | 
|  | NumEntries = 0; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const SpillSlot Offsets[] = { | 
|  | // Floating-point register save area offsets. | 
|  | {PPC::F31, -8}, | 
|  | {PPC::F30, -16}, | 
|  | {PPC::F29, -24}, | 
|  | {PPC::F28, -32}, | 
|  | {PPC::F27, -40}, | 
|  | {PPC::F26, -48}, | 
|  | {PPC::F25, -56}, | 
|  | {PPC::F24, -64}, | 
|  | {PPC::F23, -72}, | 
|  | {PPC::F22, -80}, | 
|  | {PPC::F21, -88}, | 
|  | {PPC::F20, -96}, | 
|  | {PPC::F19, -104}, | 
|  | {PPC::F18, -112}, | 
|  | {PPC::F17, -120}, | 
|  | {PPC::F16, -128}, | 
|  | {PPC::F15, -136}, | 
|  | {PPC::F14, -144}, | 
|  |  | 
|  | // General register save area offsets. | 
|  | {PPC::R31, -4}, | 
|  | {PPC::R30, -8}, | 
|  | {PPC::R29, -12}, | 
|  | {PPC::R28, -16}, | 
|  | {PPC::R27, -20}, | 
|  | {PPC::R26, -24}, | 
|  | {PPC::R25, -28}, | 
|  | {PPC::R24, -32}, | 
|  | {PPC::R23, -36}, | 
|  | {PPC::R22, -40}, | 
|  | {PPC::R21, -44}, | 
|  | {PPC::R20, -48}, | 
|  | {PPC::R19, -52}, | 
|  | {PPC::R18, -56}, | 
|  | {PPC::R17, -60}, | 
|  | {PPC::R16, -64}, | 
|  | {PPC::R15, -68}, | 
|  | {PPC::R14, -72}, | 
|  |  | 
|  | // CR save area offset. | 
|  | // FIXME SVR4: Disable CR save area for now. | 
|  | //      {PPC::CR2, -4}, | 
|  | //      {PPC::CR3, -4}, | 
|  | //      {PPC::CR4, -4}, | 
|  | //      {PPC::CR2LT, -4}, | 
|  | //      {PPC::CR2GT, -4}, | 
|  | //      {PPC::CR2EQ, -4}, | 
|  | //      {PPC::CR2UN, -4}, | 
|  | //      {PPC::CR3LT, -4}, | 
|  | //      {PPC::CR3GT, -4}, | 
|  | //      {PPC::CR3EQ, -4}, | 
|  | //      {PPC::CR3UN, -4}, | 
|  | //      {PPC::CR4LT, -4}, | 
|  | //      {PPC::CR4GT, -4}, | 
|  | //      {PPC::CR4EQ, -4}, | 
|  | //      {PPC::CR4UN, -4}, | 
|  |  | 
|  | // VRSAVE save area offset. | 
|  | {PPC::VRSAVE, -4}, | 
|  |  | 
|  | // Vector register save area | 
|  | {PPC::V31, -16}, | 
|  | {PPC::V30, -32}, | 
|  | {PPC::V29, -48}, | 
|  | {PPC::V28, -64}, | 
|  | {PPC::V27, -80}, | 
|  | {PPC::V26, -96}, | 
|  | {PPC::V25, -112}, | 
|  | {PPC::V24, -128}, | 
|  | {PPC::V23, -144}, | 
|  | {PPC::V22, -160}, | 
|  | {PPC::V21, -176}, | 
|  | {PPC::V20, -192} | 
|  | }; | 
|  |  | 
|  | static const SpillSlot Offsets64[] = { | 
|  | // Floating-point register save area offsets. | 
|  | {PPC::F31, -8}, | 
|  | {PPC::F30, -16}, | 
|  | {PPC::F29, -24}, | 
|  | {PPC::F28, -32}, | 
|  | {PPC::F27, -40}, | 
|  | {PPC::F26, -48}, | 
|  | {PPC::F25, -56}, | 
|  | {PPC::F24, -64}, | 
|  | {PPC::F23, -72}, | 
|  | {PPC::F22, -80}, | 
|  | {PPC::F21, -88}, | 
|  | {PPC::F20, -96}, | 
|  | {PPC::F19, -104}, | 
|  | {PPC::F18, -112}, | 
|  | {PPC::F17, -120}, | 
|  | {PPC::F16, -128}, | 
|  | {PPC::F15, -136}, | 
|  | {PPC::F14, -144}, | 
|  |  | 
|  | // General register save area offsets. | 
|  | // FIXME 64-bit SVR4: Are 32-bit registers actually allocated in 64-bit | 
|  | //                    mode? | 
|  | {PPC::R31, -4}, | 
|  | {PPC::R30, -12}, | 
|  | {PPC::R29, -20}, | 
|  | {PPC::R28, -28}, | 
|  | {PPC::R27, -36}, | 
|  | {PPC::R26, -44}, | 
|  | {PPC::R25, -52}, | 
|  | {PPC::R24, -60}, | 
|  | {PPC::R23, -68}, | 
|  | {PPC::R22, -76}, | 
|  | {PPC::R21, -84}, | 
|  | {PPC::R20, -92}, | 
|  | {PPC::R19, -100}, | 
|  | {PPC::R18, -108}, | 
|  | {PPC::R17, -116}, | 
|  | {PPC::R16, -124}, | 
|  | {PPC::R15, -132}, | 
|  | {PPC::R14, -140}, | 
|  |  | 
|  | {PPC::X31, -8}, | 
|  | {PPC::X30, -16}, | 
|  | {PPC::X29, -24}, | 
|  | {PPC::X28, -32}, | 
|  | {PPC::X27, -40}, | 
|  | {PPC::X26, -48}, | 
|  | {PPC::X25, -56}, | 
|  | {PPC::X24, -64}, | 
|  | {PPC::X23, -72}, | 
|  | {PPC::X22, -80}, | 
|  | {PPC::X21, -88}, | 
|  | {PPC::X20, -96}, | 
|  | {PPC::X19, -104}, | 
|  | {PPC::X18, -112}, | 
|  | {PPC::X17, -120}, | 
|  | {PPC::X16, -128}, | 
|  | {PPC::X15, -136}, | 
|  | {PPC::X14, -144}, | 
|  |  | 
|  | // CR save area offset. | 
|  | // FIXME SVR4: Disable CR save area for now. | 
|  | //      {PPC::CR2, -4}, | 
|  | //      {PPC::CR3, -4}, | 
|  | //      {PPC::CR4, -4}, | 
|  | //      {PPC::CR2LT, -4}, | 
|  | //      {PPC::CR2GT, -4}, | 
|  | //      {PPC::CR2EQ, -4}, | 
|  | //      {PPC::CR2UN, -4}, | 
|  | //      {PPC::CR3LT, -4}, | 
|  | //      {PPC::CR3GT, -4}, | 
|  | //      {PPC::CR3EQ, -4}, | 
|  | //      {PPC::CR3UN, -4}, | 
|  | //      {PPC::CR4LT, -4}, | 
|  | //      {PPC::CR4GT, -4}, | 
|  | //      {PPC::CR4EQ, -4}, | 
|  | //      {PPC::CR4UN, -4}, | 
|  |  | 
|  | // VRSAVE save area offset. | 
|  | {PPC::VRSAVE, -4}, | 
|  |  | 
|  | // Vector register save area | 
|  | {PPC::V31, -16}, | 
|  | {PPC::V30, -32}, | 
|  | {PPC::V29, -48}, | 
|  | {PPC::V28, -64}, | 
|  | {PPC::V27, -80}, | 
|  | {PPC::V26, -96}, | 
|  | {PPC::V25, -112}, | 
|  | {PPC::V24, -128}, | 
|  | {PPC::V23, -144}, | 
|  | {PPC::V22, -160}, | 
|  | {PPC::V21, -176}, | 
|  | {PPC::V20, -192} | 
|  | }; | 
|  |  | 
|  | if (Subtarget.isPPC64()) { | 
|  | NumEntries = array_lengthof(Offsets64); | 
|  |  | 
|  | return Offsets64; | 
|  | } else { | 
|  | NumEntries = array_lengthof(Offsets); | 
|  |  | 
|  | return Offsets; | 
|  | } | 
|  | } | 
|  | }; | 
|  |  | 
|  | } // End llvm namespace | 
|  |  | 
|  | #endif |