compiling newlib

[Christophe MONAT]

Paul,

My bad -- probably the mix of glibc and libm-newlib at link-time, sorry for the noise.

Thanks for your pointer, indeed I was aware of your work on that topic ("Accuracy of Mathematical Functions in Single Precision") . Claude-Pierre Jeannerod mentioned it to me some time ago and I had a look - I encourage readers of the list interested by that topic to read it too.

Best regards,
--C

-----Original Message-----
From: Paul Zimmermann <Paul.Zimmermann@inria.fr> 
Sent: Tuesday, August 25, 2020 10:39 AM
To: Christophe MONAT <christophe.monat@st.com>
Cc: newlib@sourceware.org; jjohnstn@redhat.com
Subject: Re: compiling newlib

       Dear Christophe,

> + #include <errno.h>
> probably would have avoided the trouble to add newlib-specific code.

of course I tried, but I get with #include <errno.h>:

$ gcc e.c /localdisk/zimmerma/newlib/libm/libm.a
/usr/bin/ld: /localdisk/zimmerma/newlib/libm/libm.a(lib_a-k_standard.o): in function `__kernel_standard':
k_standard.c:(.text+0x39): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0x59): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0x7f): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0xa1): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0xc1): undefined reference to `__errno'
/usr/bin/ld: /localdisk/zimmerma/newlib/libm/libm.a(lib_a-k_standard.o):k_standard.c:(.text+0xe9): more undefined references to `__errno' follow
collect2: error: ld returned 1 exit status

Best regards,
Paul

PS: I discovered that while comparing different libraries for single-precision
functions: <https://members.loria.fr/PZimmermann/papers/accuracy.pdf>