It's unclear why this was added originally, but assuming it was needed
20 years ago, it shouldn't be explicitly required nowadays. Current
versions of autotools already take care of exporting LDFLAGS to the
Makefile as needed (things are actually getting linked). That's why
the configure diffs show LDFLAGS still here, but shifted to a diff
place in the output list. A few dirs stop exporting LDFLAGS, but
that's because they don't do any linking, only compiling, so it's
correct.
As for the use of $ldflags instead of the standard $LDFLAGS, I can't
really explain that at all. Just use the right name so users don't
have to dig into why their setting isn't respected, and then use a
non-standard name instead. Adjust the testsuite to match.
Since AM_INIT_AUTOMAKE calls AC_PROG_AWK, and some configure.ac
scripts call it too, we end up testing for awk multiple times. If
we change NEWLIB_CONFIGURE to require the macro instead, then it
makes sure it's always expanded, but only once.
While we're here, do the same thing with AC_PROG_INSTALL since it
is also called by AM_INIT_AUTOMAKE, although it doesn't currently
result in duplicate configure checks.
This matches what the other GNU toolchain projects have done already.
The generated diff in practice isn't terribly large. This will allow
more use of subdir local.mk includes due to fixes & improvements that
came after the 1.11 release series.
The newlib & libgloss dirs are already generated using autoconf-2.69.
To avoid merging new code and/or accidental regeneration using diff
versions, leverage config/override.m4 to pin to 2.69 exactly. This
matches what gcc/binutils/gdb are already doing.
The README file already says to use autoconf-2.69.
To accomplish this, it's just as simple as adding -I flags to the
top-level config/ dir when running aclocal. This is because the
override.m4 file overrides AC_INIT to first require the specific
autoconf version before calling the real AC_INIT.
This patch to the libc/machine/nvptx port of newlib implements an
approximation of "clock" and provides some additional stub routines.
These changes not only reduce the number of (link) failures in the GCC
testsuite when targeting nvptx-none, but also allow the NIST scimark4
benchmark to compile and run without modification.
newlib already contains support for backends to provide their own
clock implementations via -DCLOCK_PROVIDED. That functionality is
used here to return an approximate elapsed time based on the NVidia
GPU's clock64 cycle counter. Although not great, this is better than
the current behaviour of link error from the unresolved symbol
_times_r.
The other part of the patch is to add a small number of stub functions
to nvptx's misc.c. Adding isatty, for example, resolves linking
problems in libc from the dependency in __smakebuf_r, and the sync
stub, for example, fixes the failure with GCC's
testsuite/gfortran.dg/ISO_Fortran_binding_14.f90 [which simply tests
that gfortran can call a/any C function].
newlib/
configure.host: Add -DCLOCK_PROVIDED to newlib_cflags on nvptx*.
newlib/libc/machine/nvptx
Makefile.am: Add clock.c to lib_a_SOURCES.
clock.c: New source file to implement/approximate clock().
misc.c: Add stubs for fstat, isatty, open, sync and unlink.
- From: Cesar Philippidis <cesar@codesourcery.com>
Date: Tue, 10 Apr 2018 14:43:42 -0700
Subject: [PATCH] nvptx port
This port adds support for Nvidia GPU's, which are primarily used as
offload accelerators in OpenACC and OpenMP.
Mike Frysinger
Jeff Johnston
Jon Turney
Roger Sayle
Jon Beniston