Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123170 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCFrameLowering.h b/lib/Target/PowerPC/PPCFrameLowering.h
new file mode 100644
index 0000000..0c18de1
--- /dev/null
+++ b/lib/Target/PowerPC/PPCFrameLowering.h
@@ -0,0 +1,322 @@
+//==-- 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 getInitialFrameState(std::vector<MachineMove> &Moves) 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