Tidied up TRUNC combine code. NFC.

Make use of DAG.getBitcast and use clang-format to reduce number of lines (and make it more readable).

llvm-svn: 258644

1 files changed, 5 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 98caf5b2c43..35801474e1c 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -7020,12 +7020,11 @@ SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
   if (N0.getOpcode() == ISD::ZERO_EXTEND ||
       N0.getOpcode() == ISD::SIGN_EXTEND ||
       N0.getOpcode() == ISD::ANY_EXTEND) {
+    // if the source is smaller than the dest, we still need an extend.
     if (N0.getOperand(0).getValueType().bitsLT(VT))
-      // if the source is smaller than the dest, we still need an extend
-      return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
-                         N0.getOperand(0));
+      return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
+    // if the source is larger than the dest, than we just need the truncate.
     if (N0.getOperand(0).getValueType().bitsGT(VT))
-      // if the source is larger than the dest, than we just need the truncate
       return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
     // if the source and dest are the same type, we can drop both the extend
     // and the truncate.
@@ -7061,12 +7060,9 @@ SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
       EVT IndexTy = TLI.getVectorIdxTy(DAG.getDataLayout());
       int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));
 
-      SDValue V = DAG.getNode(ISD::BITCAST, SDLoc(N),
-                              NVT, N0.getOperand(0));
-
       SDLoc DL(N);
-      return DAG.getNode(ISD::EXTRACT_VECTOR_ELT,
-                         DL, TrTy, V,
+      return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, TrTy,
+                         DAG.getBitcast(NVT, N0.getOperand(0)),
                          DAG.getConstant(Index, DL, IndexTy));
     }
   }