Re-apply 132758 and 132768 which were speculatively reverted in 132777.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133494 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 3 deletions

diff --git a/lib/Target/Mips/MipsMachineFunction.h b/lib/Target/Mips/MipsMachineFunction.h
index df40e6c..dbb7a67 100644
--- a/lib/Target/Mips/MipsMachineFunction.h
+++ b/lib/Target/Mips/MipsMachineFunction.h
@@ -27,6 +27,7 @@ namespace llvm {
 class MipsFunctionInfo : public MachineFunctionInfo {
 
 private:
+  MachineFunction& MF;
   /// SRetReturnReg - Some subtargets require that sret lowering includes
   /// returning the value of the returned struct in a register. This field
   /// holds the virtual register into which the sret argument is passed.
@@ -47,6 +48,7 @@ private:
   //                LowerCall except for the frame object for restoring $gp. 
   std::pair<int, int> InArgFIRange, OutArgFIRange;
   int GPFI; // Index of the frame object for restoring $gp 
+  mutable int DynAllocFI; // Frame index of dynamically allocated stack area.   
   unsigned MaxCallFrameSize;
 
   /// AtomicFrameIndex - To implement atomic.swap and atomic.cmp.swap
@@ -55,10 +57,10 @@ private:
   int AtomicFrameIndex;
 public:
   MipsFunctionInfo(MachineFunction& MF)
-  : SRetReturnReg(0), GlobalBaseReg(0),
+  : MF(MF), SRetReturnReg(0), GlobalBaseReg(0),
     VarArgsFrameIndex(0), InArgFIRange(std::make_pair(-1, 0)),
-    OutArgFIRange(std::make_pair(-1, 0)), GPFI(0), MaxCallFrameSize(0),
-    AtomicFrameIndex(-1)
+    OutArgFIRange(std::make_pair(-1, 0)), GPFI(0), DynAllocFI(0),
+    MaxCallFrameSize(0), AtomicFrameIndex(-1)
   {}
 
   bool isInArgFI(int FI) const {
@@ -81,6 +83,16 @@ public:
   bool needGPSaveRestore() const { return getGPFI(); }
   bool isGPFI(int FI) const { return GPFI && GPFI == FI; }
 
+  // The first call to this function creates a frame object for dynamically
+  // allocated stack area.
+  int getDynAllocFI() const {
+    if (!DynAllocFI)
+      DynAllocFI = MF.getFrameInfo()->CreateFixedObject(4, 0, true);
+
+    return DynAllocFI;
+  }
+  bool isDynAllocFI(int FI) const { return DynAllocFI && DynAllocFI == FI; }
+
   unsigned getSRetReturnReg() const { return SRetReturnReg; }
   void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }