[llvm-dev] report a clang bug: SSE4.1 instruction problem (original) (raw)
wade via llvm-dev llvm-dev at lists.llvm.org
Thu Aug 5 18:52:52 PDT 2021
- Previous message: [llvm-dev] Questions for extending llvm back-end instruction
- Next message: [llvm-dev] report a clang bug: SSE4.1 instruction problem
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Hi, I was build SSE performance work on mac intel. But I found the performance of my SSE4.1 version code using in xcode 12.4 is not as good as xcode 10.1, so I checked the assembly of my code. The one _mm_mul_epi() instruction was translated into three pmuludq, which is the SSE2 instruction, while this was normal when compiling on xcode 10.1 and _mm_mul_epi() was translated into pmuldq. So I checked the clang version, and I found this error occured when clang version larger than 7.0.0. The simple case can be found: https://godbolt.org/z/Tf7qeocvz I probably think this is a clang compiler bug. And I hope to get some advice on how to solve this issue. Thanks. Best, Wade
-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20210806/c2657852/attachment.html>
- Previous message: [llvm-dev] Questions for extending llvm back-end instruction
- Next message: [llvm-dev] report a clang bug: SSE4.1 instruction problem
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]