Push constness through LoopInfo::isLoopHeader and clean it up a bit.

[oota-llvm.git] / include / llvm / CodeGen / MachineFrameInfo.h

diff --git a/include/llvm/CodeGen/MachineFrameInfo.h b/include/llvm/CodeGen/MachineFrameInfo.h
index dca809177d4b07a2b62cb8614a64b144bd9e7235..3889d471ccf3f192065a786c99dad6f03f1a124f 100644 (file)
--- a/include/llvm/CodeGen/MachineFrameInfo.h
+++ b/include/llvm/CodeGen/MachineFrameInfo.h
@@ -121,7 +121,11 @@ class MachineFrameInfo {
         isSpillSlot(isSS), Alloca(Val), PreAllocated(false), isAliased(A) {}
   };
 
-  const TargetMachine &TM;
+  /// StackAlignment - The alignment of the stack.
+  unsigned StackAlignment;
+
+  /// StackRealignable - Can the stack be realigned.
+  bool StackRealignable;
 
   /// Objects - The list of stack objects allocated...
   ///
@@ -239,10 +243,24 @@ class MachineFrameInfo {
   /// True if the function contains a call to the llvm.vastart intrinsic.
   bool HasVAStart;
 
-  const TargetFrameLowering *getFrameLowering() const;
+  /// True if this is a varargs function that contains a musttail call.
+  bool HasMustTailInVarArgFunc;
+
+  /// True if this function contains a tail call. If so immutable objects like
+  /// function arguments are no longer so. A tail call *can* override fixed
+  /// stack objects like arguments so we can't treat them as immutable.
+  bool HasTailCall;
+
+  /// Not null, if shrink-wrapping found a better place for the prologue.
+  MachineBasicBlock *Save;
+  /// Not null, if shrink-wrapping found a better place for the epilogue.
+  MachineBasicBlock *Restore;
+
 public:
-    explicit MachineFrameInfo(const TargetMachine &TM, bool RealignOpt)
-    : TM(TM), RealignOption(RealignOpt) {
+  explicit MachineFrameInfo(unsigned StackAlign, bool isStackRealign,
+                            bool RealignOpt)
+      : StackAlignment(StackAlign), StackRealignable(isStackRealign),
+        RealignOption(RealignOpt) {
     StackSize = NumFixedObjects = OffsetAdjustment = MaxAlignment = 0;
     HasVarSizedObjects = false;
     FrameAddressTaken = false;
@@ -260,6 +278,10 @@ public:
     UseLocalStackAllocationBlock = false;
     HasInlineAsmWithSPAdjust = false;
     HasVAStart = false;
+    HasMustTailInVarArgFunc = false;
+    Save = nullptr;
+    Restore = nullptr;
+    HasTailCall = false;
   }
 
   /// hasStackObjects - Return true if there are any stack objects in this
@@ -483,6 +505,14 @@ public:
   bool hasVAStart() const { return HasVAStart; }
   void setHasVAStart(bool B) { HasVAStart = B; }
 
+  /// Returns true if the function is variadic and contains a musttail call.
+  bool hasMustTailInVarArgFunc() const { return HasMustTailInVarArgFunc; }
+  void setHasMustTailInVarArgFunc(bool B) { HasMustTailInVarArgFunc = B; }
+
+  /// Returns true if the function contains a tail call.
+  bool hasTailCall() const { return HasTailCall; }
+  void setHasTailCall() { HasTailCall = true; }
+
   /// getMaxCallFrameSize - Return the maximum size of a call frame that must be
   /// allocated for an outgoing function call.  This is only available if
   /// CallFrameSetup/Destroy pseudo instructions are used by the target, and
@@ -520,6 +550,9 @@ public:
   /// isImmutableObjectIndex - Returns true if the specified index corresponds
   /// to an immutable object.
   bool isImmutableObjectIndex(int ObjectIdx) const {
+    // Tail calling functions can clobber their function arguments.
+    if (HasTailCall)
+      return false;
     assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
            "Invalid Object Idx!");
     return Objects[ObjectIdx+NumFixedObjects].isImmutable;
@@ -584,16 +617,20 @@ public:
 
   void setCalleeSavedInfoValid(bool v) { CSIValid = v; }
 
-  /// getPristineRegs - Return a set of physical registers that are pristine on
-  /// entry to the MBB.
+  MachineBasicBlock *getSavePoint() const { return Save; }
+  void setSavePoint(MachineBasicBlock *NewSave) { Save = NewSave; }
+  MachineBasicBlock *getRestorePoint() const { return Restore; }
+  void setRestorePoint(MachineBasicBlock *NewRestore) { Restore = NewRestore; }
+
+  /// Return a set of physical registers that are pristine.
   ///
   /// Pristine registers hold a value that is useless to the current function,
-  /// but that must be preserved - they are callee saved registers that have not
-  /// been saved yet.
+  /// but that must be preserved - they are callee saved registers that are not
+  /// saved.
   ///
   /// Before the PrologueEpilogueInserter has placed the CSR spill code, this
   /// method always returns an empty set.
-  BitVector getPristineRegs(const MachineBasicBlock *MBB) const;
+  BitVector getPristineRegs(const MachineFunction &MF) const;
 
   /// print - Used by the MachineFunction printer to print information about
   /// stack objects. Implemented in MachineFunction.cpp