[llvm] r229669 - [x86] Switch an if which is trivially true to an assert. NFC

[Chandler Carruth]

Author: chandlerc
Date: Wed Feb 18 05:46:27 2015
New Revision: 229669

URL: http://llvm.org/viewvc/llvm-project?rev=229669&view=rev
Log:
[x86] Switch an if which is trivially true to an assert. NFC

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=229669&r1=229668&r2=229669&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Wed Feb 18 05:46:27 2015
@@ -8618,26 +8618,26 @@ static SDValue lowerV2I64VectorShuffle(S
         DAG.getNode(X86ISD::PSHUFD, SDLoc(Op), MVT::v4i32, V1,
                     getV4X86ShuffleImm8ForMask(WidenedMask, DAG)));
   }
+  assert((Mask[0] >= 2) + (Mask[1] >= 2) == 1 &&
+         "Canonicalization ensures we only see shuffles with two inputs.");
 
   // Try to use shift instructions.
   if (SDValue Shift =
           lowerVectorShuffleAsShift(DL, MVT::v2i64, V1, V2, Mask, DAG))
     return Shift;
 
-  // If we have a single input from V2 insert that into V1 if we can do so
-  // cheaply.
-  if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1) {
-    if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
-            MVT::v2i64, DL, V1, V2, Mask, Subtarget, DAG))
-      return Insertion;
-    // Try inverting the insertion since for v2 masks it is easy to do and we
-    // can't reliably sort the mask one way or the other.
-    int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
-                          Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
-    if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
-            MVT::v2i64, DL, V2, V1, InverseMask, Subtarget, DAG))
-      return Insertion;
-  }
+  // When loading a scalar and then shuffling it into a vector we can often do
+  // the insertion cheaply.
+  if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
+          MVT::v2i64, DL, V1, V2, Mask, Subtarget, DAG))
+    return Insertion;
+  // Try inverting the insertion since for v2 masks it is easy to do and we
+  // can't reliably sort the mask one way or the other.
+  int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
+                        Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
+  if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
+          MVT::v2i64, DL, V2, V1, InverseMask, Subtarget, DAG))
+    return Insertion;
 
   // We have different paths for blend lowering, but they all must use the
   // *exact* same predicate.