"so maybe it doesn't matter" assumes on Intel? Would the observation change on, say, ARM?
________________________________________ From: webkit-dev-boun...@lists.webkit.org [webkit-dev-boun...@lists.webkit.org] On Behalf Of Geoffrey Garen [gga...@apple.com] Sent: Friday, July 24, 2009 2:27 PM To: Darin Adler Cc: WebKit Development Subject: Re: [webkit-dev] Proposal about integer types used in WebKit > Am I missing something? Is there some real benefit to using types > like int32_t instead of int in some places in our code and not > others? If so, what are these critical places and what makes them > different from the rest of the code? In JavaScriptCore, some structures have integer members that must be 32bits in size, regardless of processor type. In those places, int32_t and uint32_t are useful. Less clear to me is whether clients of such structures should also use int32_t / uint32_t. For example: struct { int32_t i; } s; int32_t i32 = s.i; // option 1 int i = s.i; // option 2 Technically, option 2, which converts from int32_t to int, requires a "32bit move with sign extension to 64bit" instead of just a "32bit move", but Intel's documentation says that 32bit to 64bit sign extension is the very fastest instruction on the processor, so maybe it doesn't matter. Geoff _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev