[x86] Refactor some tablegen instruction info classes slightly to prepare for another...

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

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 97f86e2760d4a893aa7ebf5ef3b2da77d3205aa6..09e651cebfb926122011d2d18e96e9c41c6a94ed 100644 (file)
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -122,7 +122,7 @@ X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
 const TargetRegisterClass*
 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{
   // Don't allow super-classes of GR8_NOREX.  This class is only used after
-  // extrating sub_8bit_hi sub-registers.  The H sub-registers cannot be copied
+  // extracting sub_8bit_hi sub-registers.  The H sub-registers cannot be copied
   // to the full GR8 register class in 64-bit mode, so we cannot allow the
   // reigster class inflation.
   //
@@ -443,10 +443,8 @@ bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   const Function *F = MF.getFunction();
-  unsigned StackAlign = MF.getTarget()
-                            .getSubtargetImpl()
-                            ->getFrameLowering()
-                            ->getStackAlignment();
+  unsigned StackAlign =
+    MF.getSubtarget().getFrameLowering()->getStackAlignment();
   bool requiresRealignment =
     ((MFI->getMaxAlignment() > StackAlign) ||
      F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
@@ -489,6 +487,12 @@ 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);
@@ -531,6 +535,14 @@ unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
   return TFI->hasFP(MF) ? FramePtr : StackPtr;
 }
 
+unsigned X86RegisterInfo::getPtrSizedFrameRegister(
+    const MachineFunction &MF) const {
+  unsigned FrameReg = getFrameRegister(MF);
+  if (Subtarget.isTarget64BitILP32())
+    FrameReg = getX86SubSuperRegister(FrameReg, MVT::i32, false);
+  return FrameReg;
+}
+
 namespace llvm {
 unsigned getX86SubSuperRegister(unsigned Reg, MVT::SimpleValueType VT,
                                 bool High) {