[PATCH] D109348: [X86][AVX] Prohibit creating X86ISD::VBROADCAST(128->256) when it is AVX in combineConcatVectorOps

[Bing Yu via Phabricator via llvm-commits]

yubing added inline comments.


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:50997
+    // Before AVX2, we don't have vbroadcast instruction(128->256), we prohibit
+    // creating such vbroadcast.
+    if (Op0.getOpcode() == X86ISD::VBROADCAST &&
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RKSimon wrote:
> Why not add isel patterns to handle 128 ->256 like we do for scalar broadcasts?
I didn't got your point. Would you show the code?
BTW, X86ISD::VBROADCAST(A:v2f64->B:v4f64) is broadcasting A's low f64 to B's four elements, the corresponding instruction only exist in avx2(or after avx2). Do you mean lowering into broadcast_load or something else in isel pattern?


Repository:
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  https://reviews.llvm.org/D109348/new/

https://reviews.llvm.org/D109348