On Tue, 26 Jul 2016, Warren D Smith wrote: > However, why not provide access to double-precision multiply and > add-with-carry (subtract with borrow? shift-left?) in the same fashion? > twofer x = mul(a,b); would cause x.hi and x.lo to be computed. > twofer x = addwithcarry(a,b) ditto.
If add-with-carry were provided then it would be appropriate to provide Clang-compatible __builtin_addc* (in addition to any type-generic form provided to allow the functionality to be used with types such unsigned __int128). (I don't see Clang built-ins to be compatible with for double-precision multiply.) -- Joseph S. Myers jos...@codesourcery.com
