-Revert parts of 84326 and 84411. Distinquishing between fixed and non-fixed

stack slots and giving them different PseudoSourceValue's did not fix the
problem of post-alloc scheduling miscompiling llvm itself.
- Apply Dan's conservative workaround by assuming any non fixed stack slots can
alias other memory locations. This means a load from spill slot #1 cannot 
move above a store of spill slot #2. 
- Enable post-alloc scheduling for x86 at optimization leverl Default and above.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84424 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 41 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index cd7e1fd5f2..8bd0370cc6 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3507,22 +3507,16 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Ptr, SDValue Cmp,
                                 SDValue Swp, const Value* PtrVal,
                                 unsigned Alignment) {
-  MachineFunction &MF = getMachineFunction();
-  MachineFrameInfo *FrameInfo = MF.getFrameInfo();
-
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(MemVT);
 
   // Check if the memory reference references a frame index
   if (!PtrVal)
     if (const FrameIndexSDNode *FI =
-        dyn_cast<const FrameIndexSDNode>(Ptr.getNode())) {
-      if (FrameInfo->isFixedObjectIndex(FI->getIndex()))
-        PtrVal = PseudoSourceValue::getFixedStack(FI->getIndex());
-      else
-        PtrVal = PseudoSourceValue::getStack();
-    }
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      PtrVal = PseudoSourceValue::getFixedStack(FI->getIndex());
 
+  MachineFunction &MF = getMachineFunction();
   unsigned Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
 
   // For now, atomics are considered to be volatile always.
@@ -3566,21 +3560,16 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Ptr, SDValue Val,
                                 const Value* PtrVal,
                                 unsigned Alignment) {
-  MachineFunction &MF = getMachineFunction();
-  MachineFrameInfo *FrameInfo = MF.getFrameInfo();
-
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(MemVT);
 
   // Check if the memory reference references a frame index
   if (!PtrVal)
     if (const FrameIndexSDNode *FI =
-        dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
-      if (FrameInfo->isFixedObjectIndex(FI->getIndex()))
-        PtrVal = PseudoSourceValue::getFixedStack(FI->getIndex());
-      else
-        PtrVal = PseudoSourceValue::getStack();
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      PtrVal = PseudoSourceValue::getFixedStack(FI->getIndex());
 
+  MachineFunction &MF = getMachineFunction();
   unsigned Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
 
   // For now, atomics are considered to be volatile always.
@@ -3718,21 +3707,16 @@ SelectionDAG::getLoad(ISD::MemIndexedMode AM, DebugLoc dl,
                       SDValue Ptr, SDValue Offset,
                       const Value *SV, int SVOffset, EVT MemVT,
                       bool isVolatile, unsigned Alignment) {
-  MachineFunction &MF = getMachineFunction();
-  MachineFrameInfo *FrameInfo = MF.getFrameInfo();
-
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(VT);
 
   // Check if the memory reference references a frame index
   if (!SV)
     if (const FrameIndexSDNode *FI =
-        dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
-      if (FrameInfo->isFixedObjectIndex(FI->getIndex()))
-        SV = PseudoSourceValue::getFixedStack(FI->getIndex());
-      else
-        SV = PseudoSourceValue::getStack();
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      SV = PseudoSourceValue::getFixedStack(FI->getIndex());
 
+  MachineFunction &MF = getMachineFunction();
   unsigned Flags = MachineMemOperand::MOLoad;
   if (isVolatile)
     Flags |= MachineMemOperand::MOVolatile;
@@ -3822,21 +3806,16 @@ SelectionDAG::getIndexedLoad(SDValue OrigLoad, DebugLoc dl, SDValue Base,
 SDValue SelectionDAG::getStore(SDValue Chain, DebugLoc dl, SDValue Val,
                                SDValue Ptr, const Value *SV, int SVOffset,
                                bool isVolatile, unsigned Alignment) {
-  MachineFunction &MF = getMachineFunction();
-  MachineFrameInfo *FrameInfo = MF.getFrameInfo();
-
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(Val.getValueType());
 
   // Check if the memory reference references a frame index
   if (!SV)
     if (const FrameIndexSDNode *FI =
-        dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
-      if (FrameInfo->isFixedObjectIndex(FI->getIndex()))
-        SV = PseudoSourceValue::getFixedStack(FI->getIndex());
-      else
-        SV = PseudoSourceValue::getStack();
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      SV = PseudoSourceValue::getFixedStack(FI->getIndex());
 
+  MachineFunction &MF = getMachineFunction();
   unsigned Flags = MachineMemOperand::MOStore;
   if (isVolatile)
     Flags |= MachineMemOperand::MOVolatile;
@@ -3873,21 +3852,16 @@ SDValue SelectionDAG::getTruncStore(SDValue Chain, DebugLoc dl, SDValue Val,
                                     SDValue Ptr, const Value *SV,
                                     int SVOffset, EVT SVT,
                                     bool isVolatile, unsigned Alignment) {
-  MachineFunction &MF = getMachineFunction();
-  MachineFrameInfo *FrameInfo = MF.getFrameInfo();
-
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(SVT);
 
   // Check if the memory reference references a frame index
   if (!SV)
     if (const FrameIndexSDNode *FI =
-        dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
-      if (FrameInfo->isFixedObjectIndex(FI->getIndex()))
-        SV = PseudoSourceValue::getFixedStack(FI->getIndex());
-      else
-        SV = PseudoSourceValue::getStack();
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      SV = PseudoSourceValue::getFixedStack(FI->getIndex());
 
+  MachineFunction &MF = getMachineFunction();
   unsigned Flags = MachineMemOperand::MOStore;
   if (isVolatile)
     Flags |= MachineMemOperand::MOVolatile;