2 files changed, 12 insertions, 17 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 947cd01308b..a87cc804a44 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -7850,27 +7850,21 @@ static SDValue lowerVectorShuffleAsBroadcast(MVT VT, SDLoc DL, SDValue V,
                                             "a sorted mask where the broadcast "
                                             "comes from V1.");
 
-  // Check if this is a broadcast of a scalar load -- those are more widely
-  // supported than broadcasting in-register values.
+  // Check if this is a broadcast of a scalar. We special case lowering for
+  // scalars so that we can more effectively fold with loads.
   if (V.getOpcode() == ISD::BUILD_VECTOR ||
         (V.getOpcode() == ISD::SCALAR_TO_VECTOR && BroadcastIdx == 0)) {
-    SDValue BroadcastV = V.getOperand(BroadcastIdx);
-    if (ISD::isNON_EXTLoad(BroadcastV.getNode())) {
-      // We can directly broadcast from memory.
-      return DAG.getNode(X86ISD::VBROADCAST, DL, VT, BroadcastV);
-    }
-  }
-
-  // We can't broadcast from a register w/o AVX2.
-  if (!Subtarget->hasAVX2())
-    return SDValue();
+    V = V.getOperand(BroadcastIdx);
 
-  // Check if this is a broadcast of a BUILD_VECTOR which we can always handle,
-  // or is a broadcast of the zero element.
-  if (V.getOpcode() == ISD::BUILD_VECTOR)
-    V = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, VT, V.getOperand(BroadcastIdx));
-  else if (BroadcastIdx != 0)
+    // If the scalar isn't a load we can't broadcast from it in AVX1, only with
+    // AVX2.
+    if (!Subtarget->hasAVX2() && !ISD::isNON_EXTLoad(V.getNode()))
+      return SDValue();
+  } else if (BroadcastIdx != 0 || !Subtarget->hasAVX2()) {
+    // We can't broadcast from a vector register w/o AVX2, and we can only
+    // broadcast from the zero-element of a vector register.
     return SDValue();
+  }
 
   return DAG.getNode(X86ISD::VBROADCAST, DL, VT, V);
 }
diff --git a/llvm/test/CodeGen/X86/2012-07-15-broadcastfold.ll b/llvm/test/CodeGen/X86/2012-07-15-broadcastfold.ll
index 1c39c747cdc..519c7cac736 100644
--- a/llvm/test/CodeGen/X86/2012-07-15-broadcastfold.ll
+++ b/llvm/test/CodeGen/X86/2012-07-15-broadcastfold.ll
@@ -1,4 +1,5 @@
 ; RUN: llc < %s -march=x86 -mcpu=corei7 -mattr=+avx2 | FileCheck %s
+; RUN: llc < %s -march=x86 -mcpu=corei7 -mattr=+avx2 -x86-experimental-vector-shuffle-lowering | FileCheck %s
 
 declare x86_fastcallcc i64 @barrier()