where do I get these lib/nof/* files?
Kai Ruottu
karuottu@mbnet.fi
Mon Feb 2 15:53:00 GMT 2004
On 31 Jan 2004 at 17:34, David Wuertele wrote:
> >> And now my build will finally progress past this point.
> >> Doesn't anyone else have this problem? Where the heck do I get the
> >> lib/nof/* files?
Generally you will get them by compiling glibc once again with the
'-msoft-float' option.
> Dan> You don't need those files unless you have a CPU that doesn't
> Dan> support floating point (and even then, they might be somewhere
> Dan> else; that path is right for how the ppc405 is set up).
The Linux kernel should take care of the FPU-emulation, but as its
comments ('arch/mips/math-emu') are telling:
------------------------------- clip ----------------------------
/home2/src/linux-2.4.22/arch/mips/math-emu > less cp1emu.c
/*
* cp1emu.c: a MIPS coprocessor 1 (fpu) instruction emulator
*
* MIPS floating point support
* Copyright (C) 1994-2000 Algorithmics Ltd. All rights reserved.
* http://www.algor.co.uk
*
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard,
carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc.
*
<snip>
* A complete emulator for MIPS coprocessor 1 instructions. This is
* required for #float(switch) or #float(trap), where it catches all
* COP1 instructions via the "CoProcessor Unusable" exception.
*
* More surprisingly it is also required for #float(ieee), to help
out
* the hardware fpu at the boundaries of the IEEE-754 representation
* (denormalised values, infinities, underflow, etc). It is made
* quite nasty because emulation of some non-COP1 instructions is
* required, e.g. in branch delay slots.
*
* Note if you know that you won't have an fpu, then you'll get much
* better performance by compiling with -msoft-float!
*/
------------------------------- clip ----------------------------
the '-msoft-float' option which produces direct calls to the basic
soft-float routines, can cause a better performance...
> My CPU has no floating point unit. I looked around for nof/*, but
> didn't find anything. Any suggestions?
The point is that providing the '-msoft-float' specific glibc should
not be obligatory... You can build it and try it and see whether it
helps to better the float performance.
Visiting the 'http://www.algor.co.uk' and seeing what they are
telling about MIPS, could be useful...
My stupid question related to this area is: "What is the difference
between the 'mips(el)-linux-gnu' and the 'mipsisa32(el)-linux-gnu'
targets?" The latter seems to default to the '-msoft-float', but
what is the main difference and why the people who don't have a
FPU, don't use this target name?
Cheers, Kai
------
Want more information? See the CrossGCC FAQ, http://www.objsw.com/CrossGCC/
Want to unsubscribe? Send a note to crossgcc-unsubscribe@sources.redhat.com
More information about the crossgcc
mailing list