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af2892e778
Current LLVM uses pxor+pinsrb on SSE4+ for INSERT_VECTOR_ELT(ZeroVec, 0, Elt) insead of much simpler movd. INSERT_VECTOR_ELT(ZeroVec, 0, Elt) is idiomatic construct which is used e.g. for _mm_cvtsi32_si128(Elt) and for lowest element initialization in _mm_set_epi32. So such inefficient lowering leads to significant performance digradations in ceratin cases switching from SSSE3 to SSE4. https://bugs.llvm.org/show_bug.cgi?id=41512 Here INSERT_VECTOR_ELT(ZeroVec, 0, Elt) is simply converted to SCALAR_TO_VECTOR(Elt) when applicable since latter is closer match to desired behavior and always efficiently lowered to movd and alike. Committed on behalf of @Serge_Preis (Serge Preis) Differential Revision: https://reviews.llvm.org/D60852 llvm-svn: 359545
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