From 63f3383ece25efa625eab4d0cd75b4225a3f034c Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Thu, 31 Jan 2019 14:04:07 +0000
Subject: [X86][AVX] Fold broadcast(bitcast(src)) -> bitcast(broadcast(src))

llvm-svn: 352751
---
 llvm/lib/Target/X86/X86ISelLowering.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'llvm/lib/Target')

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index cb5dce233f7..9bc3d482074 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -31938,6 +31938,14 @@ static SDValue combineTargetShuffle(SDValue N, SelectionDAG &DAG,
         return DAG.getNode(X86ISD::VBROADCAST, DL, VT,
                            DAG.getBitcast(SrcVT, Res));
     }
+    // broadcast(bitcast(src)) -> bitcast(broadcast(src))
+    // 32-bit targets have to bitcast i64 to f64, so better to bitcast upward.
+    if (Src.getOpcode() == ISD::BITCAST &&
+        SrcVT.getScalarSizeInBits() == BCVT.getScalarSizeInBits()) {
+      EVT NewVT = EVT::getVectorVT(*DAG.getContext(), BCVT.getScalarType(),
+                                   VT.getVectorNumElements());
+      return DAG.getBitcast(VT, DAG.getNode(X86ISD::VBROADCAST, DL, NewVT, BC));
+    }
     return SDValue();
   }
   case X86ISD::PSHUFD:
-- 
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