Bug#738981: Fwd: Bug#738981: Switch to use generic_fpu for ARM

[Thomas Orgis]

Am Fri, 21 Feb 2014 11:25:12 -0500
schrieb "Lennart Sorensen" <lsorense at csclub.uwaterloo.ca>: 

> Testing with the neon build I get a return code of 4, and it seems to
> be failing to run.  It was a pain to even get it to compile.  Using just
> the configure option, the assembler complained about the NEON instructions
> being invalid for the chosen cpu type.  Adding -mfpu=neon to the CFLAGS
> made it able to compile, but it still crashes with illegal instruction.
> I tried with CFLAGS set to -mcpu=cortex-a15 -mfpu=neon, and that still
> gives illegal instruction when running it.

This is weird. What happened in debian side since
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=667653#35 ? We have
the current code working on this setup:

device: iPod touch 4G with iOS 5.1.1
toolchain: gcc 4.2.1(from Xcode 3.2.6) on OSX 10.6.8, clang 3.3(from Xcode 5.0.2) on OSX 10.9.1 (double checked)
configure script option: --host=armv7-apple-darwin --with-cpu=arm_nofpu[neon] --with-audio=dummy --disable-shared --enable-static [--enable-int-quality]

Taihei also just checked the compliance of the decoder choices
including NEON. That illegal instruction ... care to fire up the
debugger to tell us where it actually occurs? The NEON assembly is
written as plain assembler input (cpp + as), you can see the
instructions we use right there and it doesn't differ from iOS.

> It might be a good idea to have the benchmark script actuall check the
> return code of system()

Yes.

> I was building and testing under Debian armhf sid.
> gcc (Debian 4.8.2-16) 4.8.2
> 
> CPU is a dual Cortex-A15 1.5GHz (TI OMAP 57xx).


Alrighty then,

Thomas
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