Fix @llvm.frameaddress codegen. FP elimination optimization should be disabled when frame address is desired. Also add support for depth > 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56683 91177308-0d34-0410-b5e6-96231b3b80d8

13 files changed, 56 insertions, 16 deletions

diff --git a/include/llvm/CodeGen/MachineFrameInfo.h b/include/llvm/CodeGen/MachineFrameInfo.h
index 6c49eaf88e..363f206348 100644
--- a/include/llvm/CodeGen/MachineFrameInfo.h
+++ b/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; }
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index 76902505bc..bfda30ee19 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -3483,10 +3483,13 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
     setValue(&I, DAG.getNode(ISD::RETURNADDR, TLI.getPointerTy(),
                              getValue(I.getOperand(1))));
     return 0;
-  case Intrinsic::frameaddress:
+  case Intrinsic::frameaddress: {
+    MachineFrameInfo *MFI = CurMBB->getParent()->getFrameInfo();
+    MFI->setFrameAddressIsTaken(true);
     setValue(&I, DAG.getNode(ISD::FRAMEADDR, TLI.getPointerTy(),
                              getValue(I.getOperand(1))));
     return 0;
+  }
   case Intrinsic::setjmp:
     return "_setjmp"+!TLI.usesUnderscoreSetJmp();
     break;
diff --git a/lib/Target/ARM/ARMRegisterInfo.cpp b/lib/Target/ARM/ARMRegisterInfo.cpp
index 7787f43ff6..d598ef68f1 100644
--- a/lib/Target/ARM/ARMRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMRegisterInfo.cpp
@@ -209,7 +209,9 @@ 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() ||
+    MFI->isFrameAddressTaken();
 }
 
 // hasReservedCallFrame - Under normal circumstances, when a frame pointer is
diff --git a/lib/Target/Alpha/AlphaRegisterInfo.cpp b/lib/Target/Alpha/AlphaRegisterInfo.cpp
index dd8460a065..3cef5957df 100644
--- a/lib/Target/Alpha/AlphaRegisterInfo.cpp
+++ b/lib/Target/Alpha/AlphaRegisterInfo.cpp
@@ -104,7 +104,7 @@ BitVector AlphaRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
 //
 bool AlphaRegisterInfo::hasFP(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
-  return MFI->hasVarSizedObjects();
+  return MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken();
 }
 
 void AlphaRegisterInfo::
diff --git a/lib/Target/CellSPU/SPURegisterInfo.cpp b/lib/Target/CellSPU/SPURegisterInfo.cpp
index 882f79f7e1..18ca7033f6 100644
--- a/lib/Target/CellSPU/SPURegisterInfo.cpp
+++ b/lib/Target/CellSPU/SPURegisterInfo.cpp
@@ -294,7 +294,8 @@ BitVector SPURegisterInfo::getReservedRegs(const MachineFunction &MF) const {
 //
 static bool needsFP(const MachineFunction &MF) {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
-  return NoFramePointerElim || MFI->hasVarSizedObjects();
+  return NoFramePointerElim || MFI->hasVarSizedObjects() ||
+    MFI->isFrameAddressTaken();
 }
 
 //--------------------------------------------------------------------------
diff --git a/lib/Target/IA64/IA64RegisterInfo.cpp b/lib/Target/IA64/IA64RegisterInfo.cpp
index 848eab8ed9..0438de151f 100644
--- a/lib/Target/IA64/IA64RegisterInfo.cpp
+++ b/lib/Target/IA64/IA64RegisterInfo.cpp
@@ -75,7 +75,9 @@ 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() ||
+    MFI->isFrameAddressTaken();
 }
 
 void IA64RegisterInfo::
diff --git a/lib/Target/Mips/MipsRegisterInfo.cpp b/lib/Target/Mips/MipsRegisterInfo.cpp
index 6d75f460d3..f09d93e04d 100644
--- a/lib/Target/Mips/MipsRegisterInfo.cpp
+++ b/lib/Target/Mips/MipsRegisterInfo.cpp
@@ -324,7 +324,9 @@ 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() ||
+    MFI->isFrameAddressTaken();
 }
 
 // This function eliminate ADJCALLSTACKDOWN, 
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 014925e1a6..155932d8d3 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -333,6 +333,7 @@ PPCRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
 static bool needsFP(const MachineFunction &MF) {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   return NoFramePointerElim || MFI->hasVarSizedObjects() ||
+    MFI->isFrameAddressTaken() ||
     (PerformTailCallOpt && MF.getInfo<PPCFunctionInfo>()->hasFastCall());
 }
 
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 267be34f4a..d8d5db92a0 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -5645,13 +5645,13 @@ 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()));
+  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
+  unsigned FrameReg = Subtarget->is64Bit() ? X86::RBP : X86::EBP;
+  SDValue FrameAddr = DAG.getRegister(FrameReg, getPointerTy());
+  while (Depth--)
+    FrameAddr = DAG.getLoad(getPointerTy(), DAG.getEntryNode(), FrameAddr,
+                            NULL, 0);
+  return FrameAddr;
 }
 
 SDValue X86TargetLowering::LowerFRAME_TO_ARGS_OFFSET(SDValue Op,
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 49766a8fc7..d618ffdeb7 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/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()));
 }
diff --git a/test/CodeGen/X86/x86-64-frameaddr.ll b/test/CodeGen/X86/x86-64-frameaddr.ll
index 86a238f6ab..80060996f3 100644
--- a/test/CodeGen/X86/x86-64-frameaddr.ll
+++ b/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*
diff --git a/test/CodeGen/X86/x86-frameaddr.ll b/test/CodeGen/X86/x86-frameaddr.ll
new file mode 100644
index 0000000000..b9d6d13880
--- /dev/null
+++ b/test/CodeGen/X86/x86-frameaddr.ll
@@ -0,0 +1,9 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep mov | grep ebp
+
+define i8* @t() nounwind {
+entry:
+	%0 = tail call i8* @llvm.frameaddress(i32 0)
+	ret i8* %0
+}
+
+declare i8* @llvm.frameaddress(i32) nounwind readnone
diff --git a/test/CodeGen/X86/x86-frameaddr2.ll b/test/CodeGen/X86/x86-frameaddr2.ll
new file mode 100644
index 0000000000..f50ab072c3
--- /dev/null
+++ b/test/CodeGen/X86/x86-frameaddr2.ll
@@ -0,0 +1,9 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep mov | count 3
+
+define i8* @t() nounwind {
+entry:
+	%0 = tail call i8* @llvm.frameaddress(i32 2)
+	ret i8* %0
+}
+
+declare i8* @llvm.frameaddress(i32) nounwind readnone