[llvm] r256849 - [X86] Determine if we have an OpaqueSPAdjustment earlier

[David Majnemer via llvm-commits]

Author: majnemer
Date: Tue Jan  5 11:46:36 2016
New Revision: 256849

URL: http://llvm.org/viewvc/llvm-project?rev=256849&view=rev
Log:
[X86] Determine if we have an OpaqueSPAdjustment earlier

We queried hasFP before we hit ExpandISelPseudos.  ExpandISelPseudos
manipulated state that hasFP relied on, potentially changing the result
after it has been queried elsewhere.

While I am not aware of any particular bug due to this state of affairs,
it seems best to avoid it entirely by changing the state during DAG
construction.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=256849&r1=256848&r2=256849&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Jan  5 11:46:36 2016
@@ -17374,6 +17374,18 @@ static SDValue LowerINTRINSIC_W_CHAIN(SD
   if (!IntrData) {
     if (IntNo == llvm::Intrinsic::x86_seh_ehregnode)
       return MarkEHRegistrationNode(Op, DAG);
+    if (IntNo == llvm::Intrinsic::x86_flags_read_u32 ||
+        IntNo == llvm::Intrinsic::x86_flags_read_u64 ||
+        IntNo == llvm::Intrinsic::x86_flags_write_u32 ||
+        IntNo == llvm::Intrinsic::x86_flags_write_u64) {
+      // We need a frame pointer because this will get lowered to a PUSH/POP
+      // sequence.
+      MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
+      MFI->setHasOpaqueSPAdjustment(true);
+      // Don't do anything here, we will expand these intrinsics out later
+      // during ExpandISelPseudos in EmitInstrWithCustomInserter.
+      return SDValue();
+    }
     return SDValue();
   }
 
@@ -22541,8 +22553,6 @@ X86TargetLowering::EmitInstrWithCustomIn
   case X86::RDFLAGS32:
   case X86::RDFLAGS64: {
     DebugLoc DL = MI->getDebugLoc();
-    MachineFunction *MF = BB->getParent();
-    MF->getFrameInfo()->setHasOpaqueSPAdjustment(true);
     const TargetInstrInfo *TII = Subtarget->getInstrInfo();
     unsigned PushF =
         MI->getOpcode() == X86::RDFLAGS32 ? X86::PUSHF32 : X86::PUSHF64;
@@ -22558,8 +22568,6 @@ X86TargetLowering::EmitInstrWithCustomIn
   case X86::WRFLAGS32:
   case X86::WRFLAGS64: {
     DebugLoc DL = MI->getDebugLoc();
-    MachineFunction *MF = BB->getParent();
-    MF->getFrameInfo()->setHasOpaqueSPAdjustment(true);
     const TargetInstrInfo *TII = Subtarget->getInstrInfo();
     unsigned Push =
         MI->getOpcode() == X86::WRFLAGS32 ? X86::PUSH32r : X86::PUSH64r;