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[Bug target/45336] pextr{b,w,d}, (worse than) redundant extensions
- From: "tbptbp at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 19 Aug 2010 19:21:03 -0000
- Subject: [Bug target/45336] pextr{b,w,d}, (worse than) redundant extensions
- References: <bug-45336-9709@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #6 from tbptbp at gmail dot com 2010-08-19 19:21 -------
Subject: Re: pextr{b,w,d}, (worse than) redundant extensions
Thank you very much for this neat patch, Jakub.
Alas, in this case, zero extension would be suboptimal and any sign
extension simply wrong: i ask for a 64bit something, pextr{b,w,d}
already zero extends.
What i have trouble understanding is why there is so much inertia
fixing builtins (to match hardware and return, say, an unsigned
byte/short/int) when nobody's supposed to use those builtins but GCC
itself. I bet you could then still have those corresponding intrinsics
sign extend, even if no one's actually doing that, not even ICC.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45336