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Hi, I was going through the X86TTIImpl::getCastInstrCost, and got a doubt on cost calculation for TRUNCATE instruction in AVX mode. In AVX2ConversionTbl & AVXConversionTbl table there is no cost defined for TRUNCATE v16i32 to v16i8, as a fallback it goes to SSE41ConversionTbl table and there it finds cost as 30 for this operation. 30 cost for this operation looks very high. Wondering why such a high cost kept for this, any pointers to understand this will be helpful...

...: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> Subject: X86 TRUNCATE cost for AVX & AVX2 mode Hi, I was going through the X86TTIImpl::getCastInstrCost, and got a doubt on cost calculation for TRUNCATE instruction in AVX mode. In AVX2ConversionTbl & AVXConversionTbl table there is no cost defined for TRUNCATE v16i32 to v16i8, as a fallback it goes to SSE41ConversionTbl table and there it finds cost as 30 for this operation. 30 cost for this operation looks very high. Wondering why such a high cost kept for this, any pointers to understand this will be helpful...