GlobalISel: handle G_SEQUENCE fallbacks gracefully.

There were two problems:
  + AArch64 was reusing random data from its binary op tables, which is
    complete nonsense for G_SEQUENCE.
  + Even when AArch64 gave up and said it couldn't handle G_SEQUENCE,
    the generic code asserted.

llvm-svn: 288836

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp b/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
index ef6c869e3ff..a5fd2fbdde1 100644
--- a/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
@@ -494,6 +494,10 @@ AArch64RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
                               AArch64::getCopyMapping(DstIsGPR, SrcIsGPR, Size),
                               /*NumOperands*/ 2};
   }
+  case TargetOpcode::G_SEQUENCE:
+    // FIXME: support this, but the generic code is really not going to do
+    // anything sane.
+    return InstructionMapping();
   default:
     break;
   }