From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Fri, 5 Oct 2018 21:44:19 +0000 (+0000)
Subject: [X86][AVX] Limit getFauxShuffleMask INSERT_SUBVECTOR support to 2 inputs
X-Git-Tag: llvmorg-8.0.0-rc1~7126
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=dc97118efe3135cdaa4aa697e9f92ca6ea294fd3;p=platform%2Fupstream%2Fllvm.git

[X86][AVX] Limit getFauxShuffleMask INSERT_SUBVECTOR support to 2 inputs

rL343853 didn't limit the number of subinputs, but we don't currently support faux shuffles with more than 2 total inputs, so put a limiter in place until this is fixed.

Found by Artem Dergachev.

llvm-svn: 343891
---

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index f63fd3e..4a6d16f 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -6414,7 +6414,8 @@ static bool getFauxShuffleMask(SDValue N, SmallVectorImpl<int> &Mask,
         Mask[i + InsertIdx] = (NumElts * (1 + InputIdx)) + ExtractIdx + M;
       }
     }
-    return true;
+    // TODO - Add support for more than 1 subinput.
+    return Ops.size() <= 2;
   }
   case ISD::SCALAR_TO_VECTOR: {
     // Match against a scalar_to_vector of an extract from a vector,