Revert r110396 to fix buildbots.

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

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 5f31e00ebabd8e1e8ab1f491425962f352116cb8..afb07405b709ae97d3f2a503ded7c48fdb415137 100644 (file)
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -38,8 +38,15 @@
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/CommandLine.h"
 using namespace llvm;
 
+static cl::opt<bool>
+ForceStackAlign("force-align-stack",
+                 cl::desc("Force align the stack to the minimum alignment"
+                           " needed for the function."),
+                 cl::init(false), cl::Hidden);
+
 X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
                                  const TargetInstrInfo &tii)
   : X86GenRegisterInfo(tm.getSubtarget<X86Subtarget>().is64Bit() ?
@@ -193,6 +200,12 @@ unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
   case X86::DR7:
     return 7;
 
+  // Pseudo index registers are equivalent to a "none"
+  // scaled index (See Intel Manual 2A, table 2-3)
+  case X86::EIZ:
+  case X86::RIZ:
+    return 4;
+
   default:
     assert(isVirtualRegister(RegNo) && "Unknown physical register!");
     llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
@@ -456,26 +469,29 @@ bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   const Function *F = MF.getFunction();
-  bool requiresRealignment =
-    RealignStack && ((MFI->getMaxAlignment() > StackAlign) ||
-                     F->hasFnAttr(Attribute::StackAlignment));
+  bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
+                               F->hasFnAttr(Attribute::StackAlignment));
 
   // FIXME: Currently we don't support stack realignment for functions with
   //        variable-sized allocas.
-  // FIXME: Temporary disable the error - it seems to be too conservative.
+  // FIXME: It's more complicated than this...
   if (0 && requiresRealignment && MFI->hasVarSizedObjects())
     report_fatal_error(
       "Stack realignment in presense of dynamic allocas is not supported");
-
-  return (requiresRealignment && !MFI->hasVarSizedObjects());
+    
+  // If we've requested that we force align the stack do so now.
+  if (ForceStackAlign)
+    return canRealignStack(MF);
+    
+  return requiresRealignment && canRealignStack(MF);
 }
 
-bool X86RegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
+bool X86RegisterInfo::hasReservedCallFrame(const MachineFunction &MF) const {
   return !MF.getFrameInfo()->hasVarSizedObjects();
 }
 
-bool X86RegisterInfo::hasReservedSpillSlot(MachineFunction &MF, unsigned Reg,
-                                           int &FrameIdx) const {
+bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
+                                           unsigned Reg, int &FrameIdx) const {
   if (Reg == FramePtr && hasFP(MF)) {
     FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
     return true;
@@ -901,6 +917,17 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
   bool HasFP = hasFP(MF);
   DebugLoc DL;
 
+  // If we're forcing a stack realignment we can't rely on just the frame
+  // info, we need to know the ABI stack alignment as well in case we
+  // have a call out.  Otherwise just make sure we have some alignment - we'll
+  // go with the minimum SlotSize.
+  if (ForceStackAlign) {
+    if (MFI->hasCalls())
+      MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
+    else if (MaxAlign < SlotSize)
+      MaxAlign = SlotSize;
+  }
+
   // Add RETADDR move area to callee saved frame size.
   int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
   if (TailCallReturnAddrDelta < 0)
@@ -979,7 +1006,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
     if (needsFrameMoves) {
       // Mark the place where EBP/RBP was saved.
       MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
-      BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addSym(FrameLabel);
+      BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(FrameLabel);
 
       // Define the current CFA rule to use the provided offset.
       if (StackSize) {
@@ -1007,7 +1034,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
     if (needsFrameMoves) {
       // Mark effective beginning of when frame pointer becomes valid.
       MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
-      BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addSym(FrameLabel);
+      BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(FrameLabel);
 
       // Define the current CFA to use the EBP/RBP register.
       MachineLocation FPDst(FramePtr);
@@ -1047,7 +1074,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
     if (!HasFP && needsFrameMoves) {
       // Mark callee-saved push instruction.
       MCSymbol *Label = MMI.getContext().CreateTempSymbol();
-      BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addSym(Label);
+      BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(Label);
 
       // Define the current CFA rule to use the provided offset.
       unsigned Ptr = StackSize ?
@@ -1119,7 +1146,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
   if ((NumBytes || PushedRegs) && needsFrameMoves) {
     // Mark end of stack pointer adjustment.
     MCSymbol *Label = MMI.getContext().CreateTempSymbol();
-    BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addSym(Label);
+    BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(Label);
 
     if (!HasFP && NumBytes) {
       // Define the current CFA rule to use the provided offset.
@@ -1172,6 +1199,17 @@ void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
   unsigned CSSize = X86FI->getCalleeSavedFrameSize();
   uint64_t NumBytes = 0;
 
+  // If we're forcing a stack realignment we can't rely on just the frame
+  // info, we need to know the ABI stack alignment as well in case we
+  // have a call out.  Otherwise just make sure we have some alignment - we'll
+  // go with the minimum.
+  if (ForceStackAlign) {
+    if (MFI->hasCalls())
+      MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
+    else
+      MaxAlign = MaxAlign ? MaxAlign : 4;
+  }
+
   if (hasFP(MF)) {
     // Calculate required stack adjustment.
     uint64_t FrameSize = StackSize - SlotSize;