Hi,
does the ARM processors have different endians than x86 platform? For
ints and/or floating points??? I get a really strange objec when
loading it from a file.
Creating manually works.
--
-Gernot
int main(int argc, char** argv) {printf
("%silto%c%cf%c gl%ssic%ccom%c" , "ma", 58, 'g', 64, "ba", 46, 10);} 4 3477
Gernot Frisch wrote: does the ARM processors have different endians than x86 platform? For ints and/or floating points??? I get a really strange objec when loading it from a file.
Most ARMs can be configured (e.g. with a pin) to have either endianness,
so it depends on your platform. The last ARM system I used was
big-endian, i.e. opposite to x86.
But comp.lang.c++ is not a very good place to ask.
--Phil.
Gernot Frisch wrote: Hi,
does the ARM processors have different endians than x86 platform? For ints and/or floating points???
And what's your question about standard C++?
I get a really strange objec when loading it from a file.
When reading or writing binary data, it's always good to write your i/o
functions in such a way that endianess doesn't matter.
Rolf Magnus wrote: Gernot Frisch wrote:
Hi,
does the ARM processors have different endians than x86 platform? For ints and/or floating points???
And what's your question about standard C++?
I get a really strange objec when loading it from a file.
When reading or writing binary data, it's always good to write your i/o functions in such a way that endianess doesn't matter.
Sometimes unavoidable, though (eg. interfacing with 3rd party software/data formats).
Out of curiosity, I've just dug up some code I once nicked off some library to detect endianess at runtime. It relies on
IEEE floating-point format details (which probably renders it somewhat non-portable - rather defeating the object of the
exercise ;-)) but may be of interest/use to the OP:
// detect computer architecture
union {double f; uint32 i[2];} convert;
convert.f = 1.0;
if (convert.i[1] == 0x3FF00000) Architecture = LITTLEENDIAN;
else if (convert.i[0] == 0x3FF00000) Architecture = BIGENDIAN;
else Architecture = NONIEEE;}
--
Lionel B
On Mon, 20 Jun 2005 12:20:38 +0100, "Lionel B" <me@privacy.net > wrote: Out of curiosity, I've just dug up some code I once nicked off some library to detect endianess at runtime. It relies on IEEE floating-point format details (which probably renders it somewhat non-portable - rather defeating the object of the exercise ;-)) but may be of interest/use to the OP:
// detect computer architecture union {double f; uint32 i[2];} convert; convert.f = 1.0; if (convert.i[1] == 0x3FF00000) Architecture = LITTLEENDIAN; else if (convert.i[0] == 0x3FF00000) Architecture = BIGENDIAN; else Architecture = NONIEEE;}
Dodgy, to put it mildly. I remember working on an early ARM about 10
years ago, which was little-endian, but which put the two halves of an
FP64 in *big*-endian order.
Another issue is that you can't normally rely on a known bit pattern
for an FP number (because of rounding issues), though 1.0 should be
Ok.
Evan This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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#if defined(BIG_ENDIAN) && !defined(LITTLE_ENDIAN)
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I thought I understood this stuff - but...
This little program (taken from W. Richard Stevens Unix Network
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