[PATCH] D142456: [AArch64][CostModel]: Add costs for zero/sign extend.

[David Sherwood via Phabricator via llvm-commits]

david-arm added inline comments.


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Comment at: llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:2066
+    // where each operation has a cost of 1.
+    { ISD::ZERO_EXTEND, MVT::nxv16i16, MVT::nxv16i8, 3},
+    { ISD::ZERO_EXTEND, MVT::nxv16i32, MVT::nxv16i8, 6},
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I think perhaps this can just be a cost of 2 because there are only 2 unpacks needed? Same for the SIGN_EXTEND case.


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Comment at: llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:2072
+    { ISD::SIGN_EXTEND, MVT::nxv16i32, MVT::nxv16i8, 8},
+    { ISD::SIGN_EXTEND, MVT::nxv16i64, MVT::nxv16i8, 16},
   };
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david-arm wrote:
> It would be good to complete the other extends from legal types here too, such as 
> 
>   { ISD::ZERO_EXTEND, MVT::nxv8i32, MVT::nxv8i16, ?},
>   { ISD::ZERO_EXTEND, MVT::nxv8i64, MVT::nxv8i16, ?},
>   { ISD::ZERO_EXTEND, MVT::nxv4i64, MVT::nxv4i32, ?},
> 
>   { ISD::SIGN_EXTEND, MVT::nxv8i32, MVT::nxv8i16, ?},
>   { ISD::SIGN_EXTEND, MVT::nxv8i64, MVT::nxv8i16, ?},
>   { ISD::SIGN_EXTEND, MVT::nxv4i64, MVT::nxv4i32, ?},
Hi @hassnaa-arm, I think this patch is still missing the other extends that @sdesmalen and I suggested?


Repository:
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  https://reviews.llvm.org/D142456/new/

https://reviews.llvm.org/D142456