[Bug middle-end/104151] [9/10/11/12 Regression] x86: excessive code generated for 128-bit byteswap

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104151

--- Comment #5 from Hongtao.liu <crazylht at gmail dot com> ---
> 1. According to ABI, uint128 is passed by 2 gpr, and there should be extra
> cost for _11 = VIEW_CONVERT_EXPR<vector(2) long unsigned int>(a_3(D));

And no scalar_cost is needed for
BIT_FIELD_REF <a_3(D), 64, 64> 1 times scalar_stmt costs 4 in body
BIT_FIELD_REF <a_3(D), 64, 0> 1 times scalar_stmt costs 4 in body