https://gcc.gnu.org/g:a92ecfb87c48c9a4c7a7e12d5ec1491198ea0e18
commit a92ecfb87c48c9a4c7a7e12d5ec1491198ea0e18
Author: Michael Meissner <meiss...@linux.ibm.com>
Date: Fri Jul 12 20:58:20 2024 -0400
Use -mcpu=power7 if needed and not -mvsx to build float128 support.
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. Add support for building the float128 support when the
default
compiler does not enable VSX.
* config/rs6000/t-float128 (FP128_CFLAGS_SW): Do not use -mvsx,
instead
use FP128_CFLAGS_VSX to optionally add -mcpu=power7.
* config/rs6000/t-float128-vsx: New file.
* configure.ac (powerpc*-*-linux*): Determine if the default
powerpc cpu
includes VSX support.
* configure: Regenerate.
Diff:
---
libgcc/config.host | 16 ++++++++++------
libgcc/config/rs6000/t-float128 | 2 +-
libgcc/config/rs6000/t-float128-vsx | 3 +++
libgcc/configure | 29 ++++++++++++++++++++++++-----
libgcc/configure.ac | 17 ++++++++++++-----
5 files changed, 50 insertions(+), 17 deletions(-)
diff --git a/libgcc/config.host b/libgcc/config.host
index 9fae51d4ce7d..804d12e8fd6a 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1291,15 +1291,19 @@ powerpc*-*-linux*)
esac
if test $libgcc_cv_powerpc_float128 = yes; then
+ if test $libgcc_cv_powerpc_vsx = no; then
+ tmake_file="${tmake_file} rs6000/t-float128-vsx"
+ fi
+
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/config/rs6000/t-float128 b/libgcc/config/rs6000/t-float128
index b09b5664af0e..8037a6290a82 100644
--- a/libgcc/config/rs6000/t-float128
+++ b/libgcc/config/rs6000/t-float128
@@ -74,7 +74,7 @@ fp128_includes = $(srcdir)/soft-fp/double.h \
$(srcdir)/soft-fp/soft-fp.h
# Build the emulator without ISA 3.0 hardware support.
-FP128_CFLAGS_SW = -Wno-type-limits -mvsx -mfloat128 \
+FP128_CFLAGS_SW = -Wno-type-limits $(FLOAT128_CFLAGS_VSX)
-mfloat128 \
-mno-float128-hardware -mno-gnu-attribute \
-I$(srcdir)/soft-fp \
-I$(srcdir)/config/rs6000 \
diff --git a/libgcc/config/rs6000/t-float128-vsx
b/libgcc/config/rs6000/t-float128-vsx
new file mode 100644
index 000000000000..c691546242d9
--- /dev/null
+++ b/libgcc/config/rs6000/t-float128-vsx
@@ -0,0 +1,3 @@
+# Add -mcpu=power7 option if the default compiler does not support VSX
+
+FLOAT128_CFLAGS_VSX = -mabi=altivec -mcpu=power7
diff --git a/libgcc/configure b/libgcc/configure
index a69d314374a3..ad12baf965f4 100755
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -5180,13 +5180,32 @@ esac
esac
case ${host} in
-# At present, we cannot turn -mfloat128 on via #pragma GCC target, so just
-# check if we have VSX (ISA 2.06) support to build the software libraries, and
-# whether the assembler can handle xsaddqp for hardware support. Also check if
-# a new glibc is being used so that __builtin_cpu_supports can be used.
+# Test if the default compiler enables VSX. If it does not, we need to build
+# the float128 bit support using -mcpu=power7 to enable the VSX instruction
set.
+#
+# Also check if a new glibc is being used so that __builtin_cpu_supports can be
+# used.
powerpc*-*-linux*)
saved_CFLAGS="$CFLAGS"
- CFLAGS="$CFLAGS -mabi=altivec -mvsx -mfloat128"
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking if VSX is enabled by
default" >&5
+$as_echo_n "checking if VSX is enabled by default... " >&6; }
+if ${libgcc_cv_powerpc_vsx+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+vector double dadd (vector double a, vector double b) { return a + b; }
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+ libgcc_cv_powerpc_vsx=yes
+else
+ libgcc_cv_powerpc_vsx=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgcc_cv_powerpc_vsx" >&5
+$as_echo "$libgcc_cv_powerpc_vsx" >&6; }
+ CFLAGS="$CFLAGS -mabi=altivec -mcpu=power7 -mfloat128"
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for PowerPC ISA 2.06 to
build __float128 libraries" >&5
$as_echo_n "checking for PowerPC ISA 2.06 to build __float128 libraries... "
>&6; }
if ${libgcc_cv_powerpc_float128+:} false; then :
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index c2749fe09584..47487d5be7bd 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -403,13 +403,20 @@ esac
esac
case ${host} in
-# At present, we cannot turn -mfloat128 on via #pragma GCC target, so just
-# check if we have VSX (ISA 2.06) support to build the software libraries, and
-# whether the assembler can handle xsaddqp for hardware support. Also check if
-# a new glibc is being used so that __builtin_cpu_supports can be used.
+# Test if the default compiler enables VSX. If it does not, we need to build
+# the float128 bit support using -mcpu=power7 to enable the VSX instruction
set.
+#
+# Also check if a new glibc is being used so that __builtin_cpu_supports can be
+# used.
powerpc*-*-linux*)
saved_CFLAGS="$CFLAGS"
- CFLAGS="$CFLAGS -mabi=altivec -mvsx -mfloat128"
+ AC_CACHE_CHECK([if VSX is enabled by default],
+ [libgcc_cv_powerpc_vsx],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE([vector double dadd (vector double a, vector double b) {
return a + b; }])],
+ [libgcc_cv_powerpc_vsx=yes],
+ [libgcc_cv_powerpc_vsx=no])])
+ CFLAGS="$CFLAGS -mabi=altivec -mcpu=power7 -mfloat128"
AC_CACHE_CHECK([for PowerPC ISA 2.06 to build __float128 libraries],
[libgcc_cv_powerpc_float128],
[AC_COMPILE_IFELSE(
