1. Redo mips16 instructions to avoid multiple opcodes for same instruction.

[oota-llvm.git] / lib / Target / Mips / Mips16RegisterInfo.cpp

diff --git a/lib/Target/Mips/Mips16RegisterInfo.cpp b/lib/Target/Mips/Mips16RegisterInfo.cpp
index e0c4971f9d42481cc0fafa3fae8e3e091a4c2034..c15d1bf52e857c1da818d8e68cb60ac0d145b6bb 100644 (file)
--- a/lib/Target/Mips/Mips16RegisterInfo.cpp
+++ b/lib/Target/Mips/Mips16RegisterInfo.cpp
@@ -55,4 +55,57 @@ void Mips16RegisterInfo::eliminateFI(MachineBasicBlock::iterator II,
                                      unsigned OpNo, int FrameIndex,
                                      uint64_t StackSize,
                                      int64_t SPOffset) const {
+      MachineInstr &MI = *II;
+      MachineFunction &MF = *MI.getParent()->getParent();
+      MachineFrameInfo *MFI = MF.getFrameInfo();
+      MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
+
+      const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+      int MinCSFI = 0;
+      int MaxCSFI = -1;
+
+      if (CSI.size()) {
+        MinCSFI = CSI[0].getFrameIdx();
+        MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
+      }
+
+      // The following stack frame objects are always
+      // referenced relative to $sp:
+      //  1. Outgoing arguments.
+      //  2. Pointer to dynamically allocated stack space.
+      //  3. Locations for callee-saved registers.
+      // Everything else is referenced relative to whatever register
+      // getFrameRegister() returns.
+      unsigned FrameReg;
+
+      if (MipsFI->isOutArgFI(FrameIndex) ||
+         (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI))
+        FrameReg = Subtarget.isABI_N64() ? Mips::SP_64 : Mips::SP;
+      else
+        FrameReg = getFrameRegister(MF);
+
+      // Calculate final offset.
+      // - There is no need to change the offset if the frame object
+      //   is one of the
+      //   following: an outgoing argument, pointer to a dynamically allocated
+      //   stack space or a $gp restore location,
+      // - If the frame object is any of the following,
+      //   its offset must be adjusted
+      //   by adding the size of the stack:
+      //   incoming argument, callee-saved register location or local variable.
+      int64_t Offset;
+
+      if (MipsFI->isOutArgFI(FrameIndex))
+        Offset = SPOffset;
+      else
+        Offset = SPOffset + (int64_t)StackSize;
+
+      Offset    += MI.getOperand(OpNo + 1).getImm();
+
+      DEBUG(errs() << "Offset     : " << Offset << "\n" << "<--------->\n");
+
+      MI.getOperand(OpNo).ChangeToRegister(FrameReg, false);
+      MI.getOperand(OpNo + 1).ChangeToImmediate(Offset);
+
+
 }