[X86] Use fresh MemOps when emitting VAARG64

Previously it copied over MachineMemOperands verbatim which caused MOV32rm to have store flags set, and MOV32mr to have load flags set. This fixes some assertions being thrown with EXPENSIVE_CHECKS on.

Committed on behalf of @luke (Luke Lau)

Differential Revision: https://reviews.llvm.org/D62726

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363268 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 8a63163..16ddc7a 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -28728,10 +28728,18 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
   unsigned ArgMode = MI.getOperand(7).getImm();
   unsigned Align = MI.getOperand(8).getImm();
 
+  MachineFunction *MF = MBB->getParent();
+
   // Memory Reference
   assert(MI.hasOneMemOperand() && "Expected VAARG_64 to have one memoperand");
-  SmallVector<MachineMemOperand *, 1> MMOs(MI.memoperands_begin(),
-                                           MI.memoperands_end());
+
+  MachineMemOperand *OldMMO = MI.memoperands().front();
+
+  // Clone the MMO into two separate MMOs for loading and storing
+  MachineMemOperand *LoadOnlyMMO = MF->getMachineMemOperand(
+      OldMMO, OldMMO->getFlags() & ~MachineMemOperand::MOStore);
+  MachineMemOperand *StoreOnlyMMO = MF->getMachineMemOperand(
+      OldMMO, OldMMO->getFlags() & ~MachineMemOperand::MOLoad);
 
   // Machine Information
   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
@@ -28796,7 +28804,6 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
     OverflowDestReg = MRI.createVirtualRegister(AddrRegClass);
 
     const BasicBlock *LLVM_BB = MBB->getBasicBlock();
-    MachineFunction *MF = MBB->getParent();
     overflowMBB = MF->CreateMachineBasicBlock(LLVM_BB);
     offsetMBB = MF->CreateMachineBasicBlock(LLVM_BB);
     endMBB = MF->CreateMachineBasicBlock(LLVM_BB);
@@ -28829,7 +28836,7 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
         .add(Index)
         .addDisp(Disp, UseFPOffset ? 4 : 0)
         .add(Segment)
-        .setMemRefs(MMOs);
+        .setMemRefs(LoadOnlyMMO);
 
     // Check if there is enough room left to pull this argument.
     BuildMI(thisMBB, DL, TII->get(X86::CMP32ri))
@@ -28854,7 +28861,7 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
         .add(Index)
         .addDisp(Disp, 16)
         .add(Segment)
-        .setMemRefs(MMOs);
+        .setMemRefs(LoadOnlyMMO);
 
     // Zero-extend the offset
     unsigned OffsetReg64 = MRI.createVirtualRegister(AddrRegClass);
@@ -28882,7 +28889,7 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
         .addDisp(Disp, UseFPOffset ? 4 : 0)
         .add(Segment)
         .addReg(NextOffsetReg)
-        .setMemRefs(MMOs);
+        .setMemRefs(StoreOnlyMMO);
 
     // Jump to endMBB
     BuildMI(offsetMBB, DL, TII->get(X86::JMP_1))
@@ -28901,7 +28908,7 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
       .add(Index)
       .addDisp(Disp, 8)
       .add(Segment)
-      .setMemRefs(MMOs);
+      .setMemRefs(LoadOnlyMMO);
 
   // If we need to align it, do so. Otherwise, just copy the address
   // to OverflowDestReg.
@@ -28938,7 +28945,7 @@ X86TargetLowering::EmitVAARG64WithCustomInserter(MachineInstr &MI,
       .addDisp(Disp, 8)
       .add(Segment)
       .addReg(NextAddrReg)
-      .setMemRefs(MMOs);
+      .setMemRefs(StoreOnlyMMO);
 
   // If we branched, emit the PHI to the front of endMBB.
   if (offsetMBB) {