[X86] Refactor X86ISelDAGToDAG::SelectAtomicLoadArith - NFC

[oota-llvm.git] / lib / Target / X86 / X86RegisterInfo.cpp

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 5b19b1237cca582185c3e200f41220e198610eaa..40796546a2adf1954244fbb426f1342ee4cc6a37 100644 (file)
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -68,8 +68,10 @@ X86RegisterInfo::X86RegisterInfo(const X86Subtarget &STI)
 
   if (Is64Bit) {
     SlotSize = 8;
-    StackPtr = X86::RSP;
-    FramePtr = X86::RBP;
+    StackPtr = (Subtarget.isTarget64BitLP64() || Subtarget.isTargetNaCl64()) ?
+        X86::RSP : X86::ESP;
+    FramePtr = (Subtarget.isTarget64BitLP64() || Subtarget.isTargetNaCl64()) ?
+        X86::RBP : X86::EBP;
   } else {
     SlotSize = 4;
     StackPtr = X86::ESP;
@@ -459,13 +461,9 @@ bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
 
 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
                                            unsigned Reg, int &FrameIdx) const {
-  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
-
-  if (Reg == FramePtr && TFI->hasFP(MF)) {
-    FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
-    return true;
-  }
-  return false;
+  // Since X86 defines assignCalleeSavedSpillSlots which always return true
+  // this function neither used nor tested.
+  llvm_unreachable("Unused function on X86. Otherwise need a test case.");
 }
 
 void
@@ -491,6 +489,12 @@ X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   else
     BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
 
+  // For LEA64_32r when BasePtr is 32-bits (X32) we can use full-size 64-bit
+  // register as source operand, semantic is the same and destination is
+  // 32-bits. It saves one byte per lea in code since 0x67 prefix is avoided.
+  if (Opc == X86::LEA64_32r && X86::GR32RegClass.contains(BasePtr))
+    BasePtr = getX86SubSuperRegister(BasePtr, MVT::i64, false);
+
   // This must be part of a four operand memory reference.  Replace the
   // FrameIndex with base register with EBP.  Add an offset to the offset.
   MI.getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);