https://gcc.gnu.org/g:097f2463d8c78602186feb731fd8732dce9f3e7c
commit 097f2463d8c78602186feb731fd8732dce9f3e7c
Author: Michael Meissner <meiss...@linux.ibm.com>
Date: Fri Jul 12 20:04:37 2024 -0400
Add checks for building the IEEE 128-bit libgcc support if VSX is not
available.
In the past, we would build libgcc and eable the float128 libraries by
adding
-mvsx -mabi=altivec to build the support libraries. However, this causes
problems if the default cpu is a 7450. This patch checks to see if can
link a
program using the options, and if we can't link the program, do not build
the
float128 libraries.
2024-07-12 Michael Meissner <meiss...@linux.ibm.com>
libgcc/
PR target/115800
PR target/113652
* config.host (powerpc*-*-linux*): Do not enable the float128
hardware
and float128 power10 hardware support unless the basic float128
support
is added.
* configure.ac (powerpc*-*-linux*): Check whether the linker and
assembler will be able to build the float128 libraries.
* configure: Regenerate.
Diff:
---
libgcc/config.host | 12 ++++-----
libgcc/configure | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++---
libgcc/configure.ac | 17 +++++++++++--
3 files changed, 88 insertions(+), 12 deletions(-)
diff --git a/libgcc/config.host b/libgcc/config.host
index 9fae51d4ce7d..261b08859a4d 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1292,14 +1292,14 @@ powerpc*-*-linux*)
if test $libgcc_cv_powerpc_float128 = yes; then
tmake_file="${tmake_file} rs6000/t-float128"
- fi
- if test $libgcc_cv_powerpc_float128_hw = yes; then
- tmake_file="${tmake_file} rs6000/t-float128-hw"
- fi
+ if test $libgcc_cv_powerpc_float128_hw = yes; then
+ tmake_file="${tmake_file} rs6000/t-float128-hw"
- if test $libgcc_cv_powerpc_3_1_float128_hw = yes; then
- tmake_file="${tmake_file} rs6000/t-float128-p10-hw"
+ if test $libgcc_cv_powerpc_3_1_float128_hw = yes; then
+ tmake_file="${tmake_file}
rs6000/t-float128-p10-hw"
+ fi
+ fi
fi
extra_parts="$extra_parts ecrti.o ecrtn.o ncrti.o ncrtn.o"
diff --git a/libgcc/configure b/libgcc/configure
index a69d314374a3..bb196c8e7b84 100755
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -1802,6 +1802,52 @@ $as_echo "$ac_res" >&6; }
eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
} # ac_fn_c_check_header_preproc
+
+# ac_fn_c_try_link LINENO
+# -----------------------
+# Try to link conftest.$ac_ext, and return whether this succeeded.
+ac_fn_c_try_link ()
+{
+ as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+ rm -f conftest.$ac_objext conftest$ac_exeext
+ if { { ac_try="$ac_link"
+case "(($ac_try" in
+ *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+ *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+ (eval "$ac_link") 2>conftest.err
+ ac_status=$?
+ if test -s conftest.err; then
+ grep -v '^ *+' conftest.err >conftest.er1
+ cat conftest.er1 >&5
+ mv -f conftest.er1 conftest.err
+ fi
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; } && {
+ test -z "$ac_c_werror_flag" ||
+ test ! -s conftest.err
+ } && test -s conftest$ac_exeext && {
+ test "$cross_compiling" = yes ||
+ test -x conftest$ac_exeext
+ }; then :
+ ac_retval=0
+else
+ $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ ac_retval=1
+fi
+ # Delete the IPA/IPO (Inter Procedural Analysis/Optimization) information
+ # created by the PGI compiler (conftest_ipa8_conftest.oo), as it would
+ # interfere with the next link command; also delete a directory that is
+ # left behind by Apple's compiler. We do this before executing the actions.
+ rm -rf conftest.dSYM conftest_ipa8_conftest.oo
+ eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+ as_fn_set_status $ac_retval
+
+} # ac_fn_c_try_link
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.
@@ -5184,6 +5230,12 @@ case ${host} in
# check if we have VSX (ISA 2.06) support to build the software libraries, and
# whether the assembler can handle xsaddqp for hardware support. Also check if
# a new glibc is being used so that __builtin_cpu_supports can be used.
+#
+# We use AC_LINK_IFELSE to verify that the assembler will not abort if given
+# the -mvsx -mabi=altivec options to compile the float128 support with VSX.
+# Otherwise if the default CPU is something like the 7450, the assembler will
+# complain when we build the float128 support.
+
powerpc*-*-linux*)
saved_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -mabi=altivec -mvsx -mfloat128"
@@ -5192,16 +5244,27 @@ $as_echo_n "checking for PowerPC ISA 2.06 to build
__float128 libraries... " >&6
if ${libgcc_cv_powerpc_float128+:} false; then :
$as_echo_n "(cached) " >&6
else
- cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ if test x$gcc_no_link = xyes; then
+ as_fn_error $? "Link tests are not allowed after GCC_NO_EXECUTABLES."
"$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
-vector double dadd (vector double a, vector double b) { return a + b; }
+volatile vector double a;
+ volatile vector double b = { 1.0, 2.0 };
+ volatile vector double c = { 3.0, 4.0 };
+ int main (void)
+ {
+ a = b + c;
+ return 0;
+ }
_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_link "$LINENO"; then :
libgcc_cv_powerpc_float128=yes
else
libgcc_cv_powerpc_float128=no
fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgcc_cv_powerpc_float128"
>&5
$as_echo "$libgcc_cv_powerpc_float128" >&6; }
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index c2749fe09584..7a30db9977bd 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -407,13 +407,26 @@ case ${host} in
# check if we have VSX (ISA 2.06) support to build the software libraries, and
# whether the assembler can handle xsaddqp for hardware support. Also check if
# a new glibc is being used so that __builtin_cpu_supports can be used.
+#
+# We use AC_LINK_IFELSE to verify that the assembler will not abort if given
+# the -mvsx -mabi=altivec options to compile the float128 support with VSX.
+# Otherwise if the default CPU is something like the 7450, the assembler will
+# complain when we build the float128 support.
+
powerpc*-*-linux*)
saved_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -mabi=altivec -mvsx -mfloat128"
AC_CACHE_CHECK([for PowerPC ISA 2.06 to build __float128 libraries],
[libgcc_cv_powerpc_float128],
- [AC_COMPILE_IFELSE(
- [AC_LANG_SOURCE([vector double dadd (vector double a, vector double b) {
return a + b; }])],
+ [AC_LINK_IFELSE(
+ [AC_LANG_SOURCE([volatile vector double a;
+ volatile vector double b = { 1.0, 2.0 };
+ volatile vector double c = { 3.0, 4.0 };
+ int main (void)
+ {
+ a = b + c;
+ return 0;
+ }])],
[libgcc_cv_powerpc_float128=yes],
[libgcc_cv_powerpc_float128=no])])
