CodeGenPrep: fall back to MVT::Other if instruction's type isn't an EVT.

The test being performed is just an approximation anyway, so it really
shouldn't crash when things don't go entirely as expected.

Should fix PR20474.

llvm-svn: 214177

1 files changed, 6 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index d5039b2e851..8b1c3ad8eab 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -662,10 +662,13 @@ SinkShiftAndTruncate(BinaryOperator *ShiftI, Instruction *User, ConstantInt *CI,
     if (!ISDOpcode)
       continue;
 
-    // If the use is actually a legal node, there will not be an implicit
-    // truncate.
+    // If the use is actually a legal node, there will not be an
+    // implicit truncate.
+    // FIXME: always querying the result type is just an
+    // approximation; some nodes' legality is determined by the
+    // operand or other means. There's no good way to find out though.
     if (TLI.isOperationLegalOrCustom(ISDOpcode,
-                                     EVT::getEVT(TruncUser->getType())))
+                                     EVT::getEVT(TruncUser->getType(), true)))
       continue;
 
     // Don't bother for PHI nodes.