If you build a little endian compiler and select a default CPU of power5
(i.e. --with-cpu=power5), GCC cannot be built. The reason is that both the
libgfortran and libstdc++-v3 libraries assume that all little endian powerpc
builds support IEEE 128-bit floating point.
However, if the default cpu does not support the VSX instruction set, then we
cannot build the IEEE 128-bit libraries. This patch fixes the libgfortran
library so if the GCC compiler does not support IEEE 128-bit floating point, the
IEEE 128-bit floating point libraries are not built. A companion patch will fix
the libstdc++-v3 library.
I have built these patches on a little endian system, doing both normal builds,
and making a build with a power5 default. There was no regression in the normal
builds. I have also built a big endian GCC compiler and there was no regression
there. Can I check this patch into the trunk?
2024-07-10 Michael Meissner <meiss...@linux.ibm.com>
libgfortran/
PR target/115800
* configure.ac (powerpc64le*-linux*): Check to see that the compiler
uses VSX before enabling IEEE 128-bit support.
* configure: Regenerate.
* kinds-override.h (GFC_REAL_17): Add check for __VSX__.
* libgfortran.h (POWER_IEEE128): Likewise.
---
libgfortran/configure | 7 +++++--
libgfortran/configure.ac | 3 +++
libgfortran/kinds-override.h | 2 +-
libgfortran/libgfortran.h | 2 +-
4 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/libgfortran/configure b/libgfortran/configure
index 11a1bc5f070..2708e5c7eca 100755
--- a/libgfortran/configure
+++ b/libgfortran/configure
@@ -5981,6 +5981,9 @@ if test "x$GCC" = "xyes"; then
#if __SIZEOF_LONG_DOUBLE__ != 16
#error long double is double
#endif
+ #if !defined(__VSX__)
+ #error VSX is not available
+ #endif
int
main ()
{
@@ -12847,7 +12850,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 12850 "configure"
+#line 12853 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -12953,7 +12956,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 12956 "configure"
+#line 12959 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
diff --git a/libgfortran/configure.ac b/libgfortran/configure.ac
index cca1ea0ea97..cfaeb9717ab 100644
--- a/libgfortran/configure.ac
+++ b/libgfortran/configure.ac
@@ -148,6 +148,9 @@ if test "x$GCC" = "xyes"; then
AC_PREPROC_IFELSE(
[AC_LANG_PROGRAM([[#if __SIZEOF_LONG_DOUBLE__ != 16
#error long double is double
+ #endif
+ #if !defined(__VSX__)
+ #error VSX is not available
#endif]],
[[(void) 0;]])],
[AM_FCFLAGS="$AM_FCFLAGS -mabi=ibmlongdouble -mno-gnu-attribute";
diff --git a/libgfortran/kinds-override.h b/libgfortran/kinds-override.h
index f6b4956c5ca..51f440e5323 100644
--- a/libgfortran/kinds-override.h
+++ b/libgfortran/kinds-override.h
@@ -30,7 +30,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If
not, see
#endif
/* Keep these conditions on one line so grep can filter it out. */
-#if defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ &&
__SIZEOF_LONG_DOUBLE__ == 16
+#if defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ &&
__SIZEOF_LONG_DOUBLE__ == 16 && defined(__VSX__)
typedef _Float128 GFC_REAL_17;
typedef _Complex _Float128 GFC_COMPLEX_17;
#define HAVE_GFC_REAL_17
diff --git a/libgfortran/libgfortran.h b/libgfortran/libgfortran.h
index 5c59ec26e16..23660335243 100644
--- a/libgfortran/libgfortran.h
+++ b/libgfortran/libgfortran.h
@@ -104,7 +104,7 @@ typedef off_t gfc_offset;
#endif
#if defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ \
- && defined __GLIBC_PREREQ
+ && defined __GLIBC_PREREQ && defined(__VSX__)
#if __GLIBC_PREREQ (2, 32)
#define POWER_IEEE128 1
#endif
--
2.45.2
--
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meiss...@linux.ibm.com
