Re-apply 56683 with fixes.

llvm-svn: 56748

include/llvm/CodeGen/MachineFrameInfo.h

@@ -118,6 +118,10 @@ class MachineFrameInfo {
   ///
   bool HasVarSizedObjects;
 
+  /// FrameAddressTaken - This boolean keeps track of whether there is a call
+  /// to builtin @llvm.frameaddress.
+  bool FrameAddressTaken;
+
   /// StackSize - The prolog/epilog code inserter calculates the final stack
   /// offsets for all of the fixed size objects, updating the Objects list
   /// above.  It then updates StackSize to contain the number of bytes that need
@@ -174,6 +178,7 @@ public:
   MachineFrameInfo(const TargetFrameInfo &tfi) : TFI(tfi) {
     StackSize = NumFixedObjects = OffsetAdjustment = MaxAlignment = 0;
     HasVarSizedObjects = false;
+    FrameAddressTaken = false;
     HasCalls = false;
     MaxCallFrameSize = 0;
     MMI = 0;
@@ -190,6 +195,12 @@ public:
   ///
   bool hasVarSizedObjects() const { return HasVarSizedObjects; }
 
+  /// isFrameAddressTaken - This method may be called any time after instruction
+  /// selection is complete to determine if there is a call to
+  /// @llvm.frameaddress in this function.
+  bool isFrameAddressTaken() const { return FrameAddressTaken; }
+  void setFrameAddressIsTaken(bool T) { FrameAddressTaken = T; }
+
   /// getObjectIndexBegin - Return the minimum frame object index...
   ///
   int getObjectIndexBegin() const { return -NumFixedObjects; }

lib/Target/ARM/ARMRegisterInfo.cpp

@@ -209,7 +209,8 @@ ARMRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
 /// or if frame pointer elimination is disabled.
 ///
 bool ARMRegisterInfo::hasFP(const MachineFunction &MF) const {
-  return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  return NoFramePointerElim || MFI->hasVarSizedObjects();
 }
 
 // hasReservedCallFrame - Under normal circumstances, when a frame pointer is

lib/Target/IA64/IA64RegisterInfo.cpp

@@ -75,7 +75,8 @@ BitVector IA64RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
 // if frame pointer elimination is disabled.
 //
 bool IA64RegisterInfo::hasFP(const MachineFunction &MF) const {
-  return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  return NoFramePointerElim || MFI->hasVarSizedObjects();
 }
 
 void IA64RegisterInfo::

lib/Target/Mips/MipsRegisterInfo.cpp

@@ -324,7 +324,8 @@ void MipsRegisterInfo::adjustMipsStackFrame(MachineFunction &MF) const
 // if frame pointer elimination is disabled.
 bool MipsRegisterInfo::
 hasFP(const MachineFunction &MF) const {
-  return (NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects());
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  return NoFramePointerElim || MFI->hasVarSizedObjects();
 }
 
 // This function eliminate ADJCALLSTACKDOWN, 

lib/Target/X86/X86ISelLowering.cpp

@@ -5645,13 +5645,15 @@ SDValue X86TargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) {
 }
 
 SDValue X86TargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) {
-  // Depths > 0 not supported yet!
-  if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() > 0)
-    return SDValue();
-
-  SDValue RetAddrFI = getReturnAddressFrameIndex(DAG);
-  return DAG.getNode(ISD::SUB, getPointerTy(), RetAddrFI,
-                     DAG.getIntPtrConstant(TD->getPointerSize()));
+  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
+  MFI->setFrameAddressIsTaken(true);
+  MVT VT = Op.getValueType();
+  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
+  unsigned FrameReg = Subtarget->is64Bit() ? X86::RBP : X86::EBP;
+  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), FrameReg, VT);
+  while (Depth--)
+    FrameAddr = DAG.getLoad(VT, DAG.getEntryNode(), FrameAddr, NULL, 0);
+  return FrameAddr;
 }
 
 SDValue X86TargetLowering::LowerFRAME_TO_ARGS_OFFSET(SDValue Op,

lib/Target/X86/X86RegisterInfo.cpp

@@ -299,6 +299,7 @@ bool X86RegisterInfo::hasFP(const MachineFunction &MF) const {
   return (NoFramePointerElim ||
           needsStackRealignment(MF) ||
           MFI->hasVarSizedObjects() ||
+          MFI->isFrameAddressTaken() ||
           MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
           (MMI && MMI->callsUnwindInit()));
 }

test/CodeGen/X86/2008-09-26-FrameAddrBug.ll

@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin9
+
+	%struct._Unwind_Context = type { [18 x i8*], i8*, i8*, i8*, %struct.dwarf_eh_bases, i32, i32, i32, [18 x i8] }
+	%struct._Unwind_Exception = type { i64, void (i32, %struct._Unwind_Exception*)*, i32, i32, [3 x i32] }
+	%struct.dwarf_eh_bases = type { i8*, i8*, i8* }
+
+declare fastcc void @uw_init_context_1(%struct._Unwind_Context*, i8*, i8*)
+
+declare i8* @llvm.eh.dwarf.cfa(i32) nounwind
+
+define hidden void @_Unwind_Resume(%struct._Unwind_Exception* %exc) noreturn noreturn {
+entry:
+	%0 = call i8* @llvm.eh.dwarf.cfa(i32 0)		; <i8*> [#uses=1]
+	call fastcc void @uw_init_context_1(%struct._Unwind_Context* null, i8* %0, i8* null)
+	unreachable
+}

test/CodeGen/X86/x86-64-frameaddr.ll

@@ -1,7 +1,6 @@
-; RUN: llvm-as < %s | llc -march=x86-64 | grep {leaq	-8(%rsp), %rax}
-@llvm.noinline = appending global [1 x i8*] [ i8* bitcast (i64* ()* @stack_end_address to i8*) ], section "llvm.metadata"
+; RUN: llvm-as < %s | llc -march=x86-64 | grep movq | grep rbp
 
-define internal i64* @stack_end_address() nounwind  {
+define i64* @stack_end_address() nounwind  {
 entry:
 	tail call i8* @llvm.frameaddress( i32 0 )
 	bitcast i8* %0 to i64*

test/CodeGen/X86/x86-frameaddr.ll

@@ -1,5 +1,4 @@
 ; RUN: llvm-as < %s | llc -march=x86 | grep mov | grep ebp
-; XFAIL: *
 
 define i8* @t() nounwind {
 entry:

test/CodeGen/X86/x86-frameaddr2.ll

@@ -1,5 +1,4 @@
 ; RUN: llvm-as < %s | llc -march=x86 | grep mov | count 3
-; XFAIL: *
 
 define i8* @t() nounwind {
 entry: