[llvm] r363268 - [X86] Use fresh MemOps when emitting VAARG64

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Thu Jun 13 07:05:37 2019
New Revision: 363268

URL: http://llvm.org/viewvc/llvm-project?rev=363268&view=rev
Log:
[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

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=363268&r1=363267&r2=363268&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Jun 13 07:05:37 2019
@@ -28728,10 +28728,18 @@ X86TargetLowering::EmitVAARG64WithCustom
   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::EmitVAARG64WithCustom
     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::EmitVAARG64WithCustom
         .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::EmitVAARG64WithCustom
         .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::EmitVAARG64WithCustom
         .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::EmitVAARG64WithCustom
       .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::EmitVAARG64WithCustom
       .addDisp(Disp, 8)
       .add(Segment)
       .addReg(NextAddrReg)
-      .setMemRefs(MMOs);
+      .setMemRefs(StoreOnlyMMO);
 
   // If we branched, emit the PHI to the front of endMBB.
   if (offsetMBB) {