At the risk of overstepping my GCN backend review remit... On Wed, 16 Jun 2021 11:34:53 +0200 Marcel Vollweiler <mar...@codesourcery.com> wrote:
> index d9fc3c2..e179ce1 100644 > --- a/gcc/configure.ac > +++ b/gcc/configure.ac > @@ -5357,6 +5357,30 @@ case "$target" in > ;; > esac > > +# This tests if the assembler supports two registers for global_load > functions +# (like in LLVM versions <12) or one register (like in > LLVM 12). +case "$target" in > + amdgcn-* | gcn-*) > + AC_MSG_CHECKING(assembler fix for global_load functions) > + gcc_cv_as_gcn_global_load_fixed=yes > + if test x$gcc_cv_as != x; then > + cat > conftest.s <<EOF > + global_store_dwordx2 v[[1:2]], v[[4:5]], s[[14:15]] > +EOF > + if $gcc_cv_as -triple=amdgcn--amdhsa -filetype=obj > -mcpu=gfx900 -o conftest.o conftest.s > /dev/null 2>&1; then > + gcc_cv_as_gcn_global_load_fixed=no > + fi > + rm -f conftest.s conftest.o conftest > + fi > + if test x$gcc_cv_as_gcn_global_load_fixed = xyes; then > + AC_DEFINE(HAVE_GCN_ASM_GLOBAL_LOAD_FIXED, 1, [Define if your > assembler has fixed global_load functions.]) > + else > + AC_DEFINE(HAVE_GCN_ASM_GLOBAL_LOAD_FIXED, 0, [Define if your > assembler has fixed global_load functions.]) > + fi > + AC_MSG_RESULT($gcc_cv_as_gcn_global_load_fixed) > + ;; > +esac I think the more-common idiom seems to be just having a single AC_DEFINE if the feature is present -- like (as a random example) HAVE_AS_IX86_REP_LOCK_PREFIX, which omits the "define ... 0" case you have here. (You'd use "#ifdef ..." instead of "#if ... == 1" to check the feature then, of course). Then OK with that change (as long as a global maintainer doesn't object in, say, the next 24 hours?) -- but please watch the mailing list for configuration problems that might spring up on other targets. Thanks, Julian
