Raspberry Pi test results

[Marius Gerbershagen]

Hi Dave,

I just opened a merge request at
https://gitlab.com/embeddable-common-lisp/ecl/merge_requests/177 based
on your idea for detecting floating point exceptions. It containts also
a new check in the configure script that should detect cases where
feenableexcept is declared but the CPU doesn't generate floating point
exceptions. Could you test whether these changes solve the problems you
reported?

Best regards,
Marius Gerbershagen

Am 31.12.19 um 23:10 schrieb Dave Richards:
> The FPU on the Raspberry Pi does not generate CPUexceptions, which
> prevents Linux from generating SIGFPE signals, which prevents ECL from
> detecting floating-point errors and delivering appropriate error
> conditions.  The patch below causes ECL to poll for floating-point
> errors (rather than relying on SIGFPEs).  This situation is properly
> detected by 'make check'.
> 
> diff --git a/src/aclocal.m4 b/src/aclocal.m4
> index d1e626a7..ffcd1ad3 100644
> --- a/src/aclocal.m4
> +++ b/src/aclocal.m4
> @@ -865,6 +865,10 @@ case "${host_cpu}" in
>  	ECL_FPE_CODE="arch/fpe_x86.c"
>  	AC_MSG_RESULT([x86_64])
>  	;;
> +   arm* )
> +	ECL_FPE_CODE="arch/fpe_fenv.c"
> +	AC_MSG_RESULT([arm])
> +	;;
>     *)
>          ECL_FPE_CODE="arch/fpe_none.c"
>  	AC_MSG_RESULT([not available])
> 
> (src/configure needs to be re-generated.)
> 
> Add the file src/c/arch/fpe_fenv.c:
> 
> /* -*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*- */
> /* vim: set filetype=c tabstop=8 shiftwidth=4 expandtab: */
> 
> /*
>     fpe_fenv.c -- ISO C99 version of the floating point code
> */
> /*
>     Copyright (c) 2005, Juan Jose Garcia Ripoll.
> 
>     ECL is free software; you can redistribute it and/or
>     modify it under the terms of the GNU Library General Public
>     License as published by the Free Software Foundation; either
>     version 2 of the License, or (at your option) any later version.
> 
>     See file '../Copyright' for full details.
> */
> 
> /*
>  * See fpe_none.c for a description
>  */
> 
> #define ecl_detect_fpe() do {                             \
>         int bits = fetestexcept(FE_ALL_EXCEPT);           \
>     unlikely_if (bits) ecl_deliver_fpe(bits); } while(0)
>