From: Ramsay Jones <ramsay@ramsay1•demon.co.uk>
To: "Torsten Bögershausen" <tboegi@web•de>
Cc: "Vicent Martí" <tanoku@gmail•com>,
"Junio C Hamano" <gitster@pobox•com>, git <git@vger•kernel.org>,
"Jeff King" <peff@peff•net>
Subject: Re: htonll, ntohll
Date: Tue, 05 Nov 2013 00:00:24 +0000 [thread overview]
Message-ID: <52783518.1030908@ramsay1.demon.co.uk> (raw)
In-Reply-To: <52725A05.1050805@web.de>
On 31/10/13 13:24, Torsten Bögershausen wrote:
> On 2013-10-30 22.07, Ramsay Jones wrote:
[ ... ]
>> Yep, this was the first thing I did as well! ;-) (*late* last night)
>>
>> I haven't had time today to look into fixing up the msvc build
>> (or a complete re-write), so I look forward to seeing your solution.
>> (do you have msvc available? - or do you want me to look at fixing
>> it? maybe in a day or two?)
>>
> Ramsay,
> I don't have msvc, so feel free to go ahead, as much as you can.
>
> I'll send a patch for the test code I have made, and put bswap.h on hold for a week
> (to be able to continue with t5601/connect.c)
Unfortunately, I haven't had much time to look into this.
I do have a patch (given below) that works on Linux, cygwin,
MinGW and msvc. However, the msvc build is still broken (as a
result of _other_ commits in this 'jk/pack-bitmap' branch; as
well as the use of a VLA in another commit).
So, I still have work to do! :(
Anyway, I thought I would send what I have, so you can take a look.
Note, that I don't have an big-endian machine to test this on, so
YMMV. Indeed, the *only* testing I have done is to run the test added
by this branch (t5310-pack-bitmaps.sh), which works on Linux, cygwin
and MinGW.
[Note: I have never particularly liked htons, htonl et.al., so adding
these htonll/ntohll functions doesn't thrill me! :-D For example see
this post[1], which echo's my sentiments exactly.]
HTH
ATB,
Ramsay Jones
[1] http://commandcenter.blogspot.co.uk/2012/04/byte-order-fallacy.html
-- >8 --
Subject: [PATCH] compat/bswap.h: Fix build on cygwin, MinGW and msvc
---
compat/bswap.h | 97 ++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 68 insertions(+), 29 deletions(-)
diff --git a/compat/bswap.h b/compat/bswap.h
index ea1a9ed..c18a78e 100644
--- a/compat/bswap.h
+++ b/compat/bswap.h
@@ -17,7 +17,20 @@ static inline uint32_t default_swab32(uint32_t val)
((val & 0x000000ff) << 24));
}
+static inline uint64_t default_bswap64(uint64_t val)
+{
+ return (((val & (uint64_t)0x00000000000000ffULL) << 56) |
+ ((val & (uint64_t)0x000000000000ff00ULL) << 40) |
+ ((val & (uint64_t)0x0000000000ff0000ULL) << 24) |
+ ((val & (uint64_t)0x00000000ff000000ULL) << 8) |
+ ((val & (uint64_t)0x000000ff00000000ULL) >> 8) |
+ ((val & (uint64_t)0x0000ff0000000000ULL) >> 24) |
+ ((val & (uint64_t)0x00ff000000000000ULL) >> 40) |
+ ((val & (uint64_t)0xff00000000000000ULL) >> 56));
+}
+
#undef bswap32
+#undef bswap64
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
@@ -32,54 +45,80 @@ static inline uint32_t git_bswap32(uint32_t x)
return result;
}
+#define bswap64 git_bswap64
+#if defined(__x86_64__)
+static inline uint64_t git_bswap64(uint64_t x)
+{
+ uint64_t result;
+ if (__builtin_constant_p(x))
+ result = default_bswap64(x);
+ else
+ __asm__("bswap %q0" : "=r" (result) : "0" (x));
+ return result;
+}
+#else
+static inline uint64_t git_bswap64(uint64_t x)
+{
+ union { uint64_t i64; uint32_t i32[2]; } tmp, result;
+ if (__builtin_constant_p(x))
+ result.i64 = default_bswap64(x);
+ else {
+ tmp.i64 = x;
+ result.i32[0] = git_bswap32(tmp.i32[1]);
+ result.i32[1] = git_bswap32(tmp.i32[0]);
+ }
+ return result.i64;
+}
+#endif
+
#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
#include <stdlib.h>
#define bswap32(x) _byteswap_ulong(x)
+#define bswap64(x) _byteswap_uint64(x)
#endif
-#ifdef bswap32
+#if defined(bswap32)
#undef ntohl
#undef htonl
#define ntohl(x) bswap32(x)
#define htonl(x) bswap32(x)
-#ifndef __BYTE_ORDER
-# if defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && defined(BIG_ENDIAN)
-# define __BYTE_ORDER BYTE_ORDER
-# define __LITTLE_ENDIAN LITTLE_ENDIAN
-# define __BIG_ENDIAN BIG_ENDIAN
-# else
-# error "Cannot determine endianness"
-# endif
+#endif
+
+#if defined(bswap64)
+
+#undef ntohll
+#undef htonll
+#define ntohll(x) bswap64(x)
+#define htonll(x) bswap64(x)
+
+#else
+
+#undef ntohll
+#undef htonll
+
+#if !defined(__BYTE_ORDER)
+# if defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && defined(BIG_ENDIAN)
+# define __BYTE_ORDER BYTE_ORDER
+# define __LITTLE_ENDIAN LITTLE_ENDIAN
+# define __BIG_ENDIAN BIG_ENDIAN
+# endif
+#endif
+
+#if !defined(__BYTE_ORDER)
+# error "Cannot determine endianness"
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
# define ntohll(n) (n)
# define htonll(n) (n)
-#elif __BYTE_ORDER == __LITTLE_ENDIAN
-# if defined(__GNUC__) && defined(__GLIBC__)
-# include <byteswap.h>
-# else /* GNUC & GLIBC */
-static inline uint64_t bswap_64(uint64_t val)
-{
- return ((val & (uint64_t)0x00000000000000ffULL) << 56)
- | ((val & (uint64_t)0x000000000000ff00ULL) << 40)
- | ((val & (uint64_t)0x0000000000ff0000ULL) << 24)
- | ((val & (uint64_t)0x00000000ff000000ULL) << 8)
- | ((val & (uint64_t)0x000000ff00000000ULL) >> 8)
- | ((val & (uint64_t)0x0000ff0000000000ULL) >> 24)
- | ((val & (uint64_t)0x00ff000000000000ULL) >> 40)
- | ((val & (uint64_t)0xff00000000000000ULL) >> 56);
-}
-# endif /* GNUC & GLIBC */
-# define ntohll(n) bswap_64(n)
-# define htonll(n) bswap_64(n)
-#else /* __BYTE_ORDER */
-# error "Can't define htonll or ntohll!"
+#else
+# define ntohll(n) default_bswap64(n)
+# define htonll(n) default_bswap64(n)
#endif
#endif
--
1.8.4
next prev parent reply other threads:[~2013-11-05 0:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-28 19:28 What's cooking in git.git (Oct 2013, #07; Mon, 28) Junio C Hamano
2013-10-28 21:58 ` Thomas Rast
2013-10-30 16:51 ` Torsten Bögershausen
2013-10-30 17:01 ` Vicent Martí
2013-10-30 17:14 ` Torsten Bögershausen
2013-10-30 17:39 ` Torsten Bögershausen
2013-10-30 19:11 ` Ramsay Jones
2013-10-30 19:06 ` Ramsay Jones
2013-10-30 20:30 ` Torsten Bögershausen
2013-10-30 21:07 ` Ramsay Jones
2013-10-31 13:24 ` htonll, ntohll Torsten Bögershausen
2013-11-05 0:00 ` Ramsay Jones [this message]
2013-11-06 15:58 ` Torsten Bögershausen
2013-11-12 14:44 ` Jakub Narębski
2013-11-13 12:20 ` Andreas Ericsson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=52783518.1030908@ramsay1.demon.co.uk \
--to=ramsay@ramsay1$(echo .)demon.co.uk \
--cc=git@vger$(echo .)kernel.org \
--cc=gitster@pobox$(echo .)com \
--cc=peff@peff$(echo .)net \
--cc=tanoku@gmail$(echo .)com \
--cc=tboegi@web$(echo .)de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox