[MIPS GlobalISel] Select G_FENCE

G_FENCE comes form fence instruction. For MIPS fence is generated in
AtomicExpandPass when atomic instruction gets surrounded with fence
instruction when needed.
G_FENCE arguments don't have LLT, because of that there is no job for
legalizer and regbankselect. Instruction select G_FENCE for MIPS32.

Differential Revision: https://reviews.llvm.org/D67181

llvm-svn: 371056

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsInstructionSelector.cpp b/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
index da319265fba..f0c3d3d46bd 100644
--- a/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
+++ b/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
@@ -752,6 +752,10 @@ bool MipsInstructionSelector::select(MachineInstr &I) {
     I.eraseFromParent();
     return true;
   }
+  case G_FENCE: {
+    MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::SYNC)).addImm(0);
+    break;
+  }
   default:
     return false;
   }