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authorJoseph Myers <joseph@codesourcery.com>2017-12-12 13:56:47 +0000
committerJoseph Myers <joseph@codesourcery.com>2017-12-12 13:56:47 +0000
commit8df5d34720dd71e934545bade879e04697830757 (patch)
treeaf607d1b63037ad92901e4ed8a4a71f95270ee31 /configure
parent0cee1257a96fc2983c7cc0717015ad54d81ceff3 (diff)
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Remove --with-fp / --without-fp.
There is a configure option --without-fp that specifies that nofpu sysdeps directories should be used instead of fpu directories. For most glibc configurations, this option is of no use: either there is no valid nofpu variant of that configuration, or there are no fpu or nofpu sysdeps directories for that processor and so the option does nothing. For a few configurations, if you are using a soft-float compiler this option is required, and failing to use it generally results in compilation errors from inline asm using unavailable floating-point instructions. We're moving away from --with-cpu to configuring glibc based on how the compiler generates code, and it is natural to do so for --without-fp as well; in most cases the soft-float and hard-float ABIs are incompatible so you have no hope of building a working glibc with an inappropriately configured compiler or libgcc. This patch eliminates --without-fp, replacing it entirely by automatic configuration based on the compiler. Configurations for which this is relevant (coldfire / mips / powerpc32 / sh) define a variable with_fp_cond in their preconfigure fragments (under the same conditions under which those fragments do anything); this is a preprocessor conditional which the toplevel configure script then uses in a test to determine which sysdeps directories to use. The config.make with-fp variable remains. It's used only by powerpc (sysdeps/powerpc/powerpc32/Makefile) to add -mhard-float to various flags variables. For powerpc, -mcpu= options can imply use of soft-float. That could be an issue if you want to build for e.g. 476fp, but are using --with-cpu=476 because there isn't a 476fp sysdeps directory. If in future we eliminate --with-cpu and replace it entirely by testing the compiler, it would be natural at that point to eliminate that code as well (as the user should then just use a compiler defaulting to 476fp and the 476 sysdeps directory would be used automatically). Tested for x86_64, and tested with build-many-glibcs.py that installed shared libraries are unchanged by this patch. * configure.ac (--with-fp): Remove configure option. (with_fp_cond): New variable. (libc_cv_with_fp): New configure test. Use this variable instead of with_fp. * configure: Regenerated. * config.make.in (with-fp): Use @libc_cv_with_fp@. * manual/install.texi (Configuring and compiling): Remove --without-fp. * INSTALL: Regenerated. * sysdeps/m68k/preconfigure (with_fp_cond): Define for ColdFire. * sysdeps/mips/preconfigure (with_fp_cond): Define. * sysdeps/powerpc/preconfigure (with_fp_cond): Define for 32-bit. * sysdeps/sh/preconfigure (with_fp_cond): Define. * scripts/build-many-glibcs.py (Context.add_all_configs): Do not use --without-fp to configure glibc.
Diffstat (limited to 'configure')
-rwxr-xr-xconfigure44
1 files changed, 31 insertions, 13 deletions
diff --git a/configure b/configure
index dd8b8c9..4a85706 100755
--- a/configure
+++ b/configure
@@ -666,6 +666,7 @@ multi_arch
no_stack_protector
stack_protector
libc_cv_ssp
+libc_cv_with_fp
base_machine
have_tunables
build_pt_chown
@@ -683,7 +684,6 @@ hardcoded_path_in_tests
enable_timezone_tools
use_default_link
sysheaders
-with_fp
ac_ct_CXX
CXXFLAGS
CXX
@@ -756,7 +756,6 @@ with_bugurl
with_gd
with_gd_include
with_gd_lib
-with_fp
with_binutils
with_selinux
with_headers
@@ -1467,7 +1466,6 @@ Optional Packages:
--with-gd=DIR find libgd include dir and library with prefix DIR
--with-gd-include=DIR find libgd include files in DIR
--with-gd-lib=DIR find libgd library files in DIR
- --with-fp if using floating-point hardware [default=yes]
--with-binutils=PATH specify location of binutils (as and ld)
--with-selinux if building with SELinux support
--with-headers=PATH location of system headers to use (for example
@@ -3294,15 +3292,6 @@ libgd-LDFLAGS = $libgd_ldflags"
fi
-# Check whether --with-fp was given.
-if test "${with_fp+set}" = set; then :
- withval=$with_fp; with_fp=$withval
-else
- with_fp=yes
-fi
-
-
-
# Check whether --with-binutils was given.
if test "${with_binutils+set}" = set; then :
withval=$with_binutils; path_binutils=$withval
@@ -3778,6 +3767,11 @@ fi
# check below.
libc_config_ok=no
+# A preconfigure script for a system that may or may not use fpu
+# sysdeps directories sets this to a preprocessor conditional for
+# whether to use such directories.
+with_fp_cond=1
+
if frags=`ls -d $srcdir/sysdeps/*/preconfigure 2> /dev/null`
then
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for sysdeps preconfigure fragments" >&5
@@ -3816,6 +3810,30 @@ fi
test -n "$base_machine" || base_machine=$machine
+# Determine whether to use fpu or nofpu sysdeps directories.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for use of fpu sysdeps directories" >&5
+$as_echo_n "checking for use of fpu sysdeps directories... " >&6; }
+if ${libc_cv_with_fp+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.c <<EOF
+#if $with_fp_cond
+int dummy;
+#else
+# error "no hardware floating point"
+#endif
+EOF
+libc_cv_with_fp=no
+if ${CC-cc} $CFLAGS $CPPFLAGS -S conftest.c -o conftest.s \
+ 1>&5 2>&5 ; then
+ libc_cv_with_fp=yes
+fi
+rm -f conftest*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_with_fp" >&5
+$as_echo "$libc_cv_with_fp" >&6; }
+
+
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for -fstack-protector" >&5
$as_echo_n "checking for -fstack-protector... " >&6; }
if ${libc_cv_ssp+:} false; then :
@@ -4085,7 +4103,7 @@ tail=$machine${submachine:+/$submachine}
while m=`echo $tail | sed 's@^\(.*\)/\([^/]*\)$@& \1@'`; test -n "$m"; do
set $m
# Prepend the machine's FPU directory unless --without-fp.
- if test "$with_fp" = yes; then
+ if test "$libc_cv_with_fp" = yes; then
maybe_fpu=/fpu
else
maybe_fpu=/nofpu