From: David Majnemer <david.majnemer@gmail.com>
Date: Tue, 5 Jan 2016 17:46:36 +0000 (+0000)
Subject: [X86] Determine if we have an OpaqueSPAdjustment earlier
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6ea7b5b53b7bd4e72b540992b8fa5bd183e70250;p=oota-llvm.git

[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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256849 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 6d748ca5164..b9863d1dea2 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -17374,6 +17374,18 @@ static SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, const X86Subtarget *Subtarget,
   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::EmitInstrWithCustomInserter(MachineInstr *MI,
   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::EmitInstrWithCustomInserter(MachineInstr *MI,
   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;