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Re: PATCH: Move sysdeps/x86_64/Implies to sysdeps/x86_64/64
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Roland McGrath <roland at hack dot frob dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Sat, 7 Apr 2012 15:19:57 +0000 (UTC)
- Subject: Re: PATCH: Move sysdeps/x86_64/Implies to sysdeps/x86_64/64
- References: <20120322175315.GA9938@intel.com> <20120322195022.F2EF32C07C@topped-with-meat.com><CAMe9rOriXXrVWVLLuES8OUAXvbcVgcJEAYAgJjHWr3YCB2JmaQ@mail.gmail.com><CAMe9rOru6EXRsoqaBKS0a9fGqwey+52DCak0MwGPM1bzWf29NQ@mail.gmail.com><20120322204013.868A12C086@topped-with-meat.com><CAMe9rOq87mKXdoMOGH=cxiq8C6qhK7bTi5bAB9jQk_Eg7x72Vw@mail.gmail.com><20120322210647.330402C07E@topped-with-meat.com><CAMe9rOpiAWE8U2XFxgavJBi9FUomTZh3XEwcdYN59qNBR8OM7g@mail.gmail.com><20120322211655.C5E992C07E@topped-with-meat.com><CAMe9rOp7AVVWn_Bo6sKC7yRuCaRxiqUXGpLCm9wqvg2aSjHx-Q@mail.gmail.com><20120322220155.1AC112C07E@topped-with-meat.com><CAMe9rOqj3J=fw984tRMG-FTgxgxbKbjRZJzrnoaOfqzAi815+g@mail.gmail.com><20120322222523.5F52A2C08D@topped-with-meat.com><CAMe9rOqqKB0g_0xoueMWX-902eOeFqpw3LmO7Ej6p=xERjWtCQ@mail.gmail.com><20120406210447.642DE2C0C4@topped-with-meat.com><CAMe9rOo1gPRVRqhTwYjwdhKWyTgn2-aJMsLnHw7ZYZjPDnGiJw@mail.gmail.com>
On Fri, 6 Apr 2012, H.J. Lu wrote:
> For x86-64, with Implies-after, the search order can only be
>
> ieee754/ldbl-96
> ieee754/dbl-64/wordsize-64
> ieee754/dbl-64
> ieee754/flt-32
> wordsize-64
>
> not
>
> wordsize-64
> ieee754/ldbl-96
> ieee754/dbl-64/wordsize-64
> ieee754/dbl-64
> ieee754/flt-32
Thanks for giving a concrete different in orders. The next question is:
why does that difference matter for x32? (If it doesn't, you need to give
an example of a case where the order *does* matter and you can't get the
order you want.)
My guess is that "wordsize-64" is being used for more than one thing, and
should actually be split up; some files may be for "64-bit operations are
efficient", some for "long and long long are both 64-bit", some for
"dirent64 is the same as dirent". If we can distinguish the various ways
"wordsize-64" is used, then x32 could use a different subset of the new
directories from pure 64-bit.
(We also need a clear statement of what the __WORDSIZE define from
bits/wordsize.h means. Given the uses in stdint.h, and existing practice
for MIPS for example, I think it's "long is 64-bit".)
--
Joseph S. Myers
joseph@codesourcery.com