diff options
-rw-r--r-- | sysdeps/powerpc/powerpc64/configure | 42 | ||||
-rw-r--r-- | sysdeps/powerpc/powerpc64/configure.ac | 25 |
2 files changed, 43 insertions, 24 deletions
diff --git a/sysdeps/powerpc/powerpc64/configure b/sysdeps/powerpc/powerpc64/configure index 5ce77af631..fddea0355a 100644 --- a/sysdeps/powerpc/powerpc64/configure +++ b/sysdeps/powerpc/powerpc64/configure @@ -32,26 +32,36 @@ if test x$libc_cv_overlapping_opd = xyes; then fi -# @notoc started to be supported in GNU Binutils 2.31. - -{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if the assembler supports @notoc" >&5 -$as_echo_n "checking if the assembler supports @notoc... " >&6; } +# We check if compiler supports @notoc generation since there is no +# gain by enabling it if it will be optimized away by the linker. +# It also helps linkers that might not optimize it and end up +# generating stubs with ISA 3.1 instruction even targetting older ISA. +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if the compiler supports @notoc" >&5 +$as_echo_n "checking if the compiler supports @notoc... " >&6; } if ${libc_cv_ppc64_notoc+:} false; then : $as_echo_n "(cached) " >&6 else - - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ - -void foo (void) {asm("b foo@notoc");} - -_ACEOF -if ac_fn_c_try_compile "$LINENO"; then : - libc_cv_ppc64_notoc=yes -else + cat > conftest.c <<EOF +int bar (void); +int foo (void) { return bar () + 1; } +EOF libc_cv_ppc64_notoc=no -fi -rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + if { ac_try='${CC-cc} $libc_cv_cc_submachine $CFLAGS $CPPFLAGS -S -o conftest.s conftest.c' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; } \ + && { ac_try='grep -q -E 'bar@notoc' conftest.s' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; } + then + libc_cv_ppc64_notoc=yes + fi + rm -rf conftest.* fi { $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_ppc64_notoc" >&5 $as_echo "$libc_cv_ppc64_notoc" >&6; } diff --git a/sysdeps/powerpc/powerpc64/configure.ac b/sysdeps/powerpc/powerpc64/configure.ac index b77156f696..1f3d54414c 100644 --- a/sysdeps/powerpc/powerpc64/configure.ac +++ b/sysdeps/powerpc/powerpc64/configure.ac @@ -22,13 +22,22 @@ if test x$libc_cv_overlapping_opd = xyes; then AC_DEFINE(USE_PPC64_OVERLAPPING_OPD) fi -# @notoc started to be supported in GNU Binutils 2.31. -AC_CACHE_CHECK([if the assembler supports @notoc], - libc_cv_ppc64_notoc, [ - AC_COMPILE_IFELSE([AC_LANG_SOURCE([ -void foo (void) {asm("b foo@notoc");} - ])], - [libc_cv_ppc64_notoc=yes], - [libc_cv_ppc64_notoc=no])]) +# We check if compiler supports @notoc generation since there is no +# gain by enabling it if it will be optimized away by the linker. +# It also helps linkers that might not optimize it and end up +# generating stubs with ISA 3.1 instruction even targetting older ISA. +AC_CACHE_CHECK([if the compiler supports @notoc], + libc_cv_ppc64_notoc, [dnl + cat > conftest.c <<EOF +int bar (void); +int foo (void) { return bar () + 1; } +EOF + libc_cv_ppc64_notoc=no + if AC_TRY_COMMAND([${CC-cc} $libc_cv_cc_submachine $CFLAGS $CPPFLAGS -S -o conftest.s conftest.c]) \ + && AC_TRY_COMMAND([grep -q -E 'bar@notoc' conftest.s]) + then + libc_cv_ppc64_notoc=yes + fi + rm -rf conftest.*]) AS_IF([test x$libc_cv_ppc64_notoc = xyes], [AC_DEFINE(USE_PPC64_NOTOC)]) |