[PATCH v5 06/12] configure: Only use -fno-fp-int-builtin-inexact if compiler supports it

[Sam James]

Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:

> Checked on x86_64-linux-gnu.

Reviewed-by: Sam James <sam@gentoo.org>

> ---
>  configure     | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  configure.ac  | 11 ++++++++++
>  math/Makefile | 32 +++++++++++++--------------
>  3 files changed, 87 insertions(+), 16 deletions(-)
>
> diff --git a/configure b/configure
> index 7883e8c99c..9b72ca3b17 100755
> --- a/configure
> +++ b/configure
> @@ -9140,6 +9140,66 @@ have-cc-gcs = $libc_cv_cc_gcs"
>  config_vars="$config_vars
>  have-test-cc-gcs = $libc_cv_test_cc_gcs"
>  
> +# Check if compiler supports -fno-fp-int-builtin-inexact
> +
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if compiler supports -fno-fp-int-builtin-inexact" >&5
> +printf %s "checking if compiler supports -fno-fp-int-builtin-inexact... " >&6; }
> +if test ${libc_cv_cc_no_fp_builtin_inexact+y}
> +then :
> +  printf %s "(cached) " >&6
> +else case e in #(
> +  e) if { ac_try='${CC-cc} -Werror -fno-fp-int-builtin-inexact -xc /dev/null -S -o /dev/null'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }
> +then :
> +  libc_cv_cc_no_fp_builtin_inexact=-fno-fp-int-builtin-inexact
> +else case e in #(
> +  e) libc_cv_cc_no_fp_builtin_inexact= ;;
> +esac
> +fi ;;
> +esac
> +fi
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_no_fp_builtin_inexact" >&5
> +printf "%s\n" "$libc_cv_cc_no_fp_builtin_inexact" >&6; }
> +if test "$TEST_CC" = "$CC"; then
> +  libc_cv_test_cc_no_fp_builtin_inexact=$libc_cv_cc_no_fp_builtin_inexact
> +else
> +
> +saved_CC="$CC"
> +CC="$TEST_CC"
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if compiler supports -fno-fp-int-builtin-inexact in testing" >&5
> +printf %s "checking if compiler supports -fno-fp-int-builtin-inexact in testing... " >&6; }
> +if test ${libc_cv_test_cc_no_fp_builtin_inexact+y}
> +then :
> +  printf %s "(cached) " >&6
> +else case e in #(
> +  e) if { ac_try='${CC-cc} -Werror -fno-fp-int-builtin-inexact -xc /dev/null -S -o /dev/null'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }
> +then :
> +  libc_cv_test_cc_no_fp_builtin_inexact=-fno-fp-int-builtin-inexact
> +else case e in #(
> +  e) libc_cv_test_cc_no_fp_builtin_inexact= ;;
> +esac
> +fi ;;
> +esac
> +fi
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_cc_no_fp_builtin_inexact" >&5
> +printf "%s\n" "$libc_cv_test_cc_no_fp_builtin_inexact" >&6; }
> +
> +CC="$saved_CC"
> +
> +fi
> +
> +config_vars="$config_vars
> +config-cflags-no-fp-builtin-inexact = $libc_cv_cc_no_fp_builtin_inexact"
> +
>  # Check if linker supports GCS marking
>  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for linker that supports -z gcs=always" >&5
>  printf %s "checking for linker that supports -z gcs=always... " >&6; }
> diff --git a/configure.ac b/configure.ac
> index 8771a738fa..ef269340cb 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -2037,6 +2037,17 @@ LIBC_TRY_CC_AND_TEST_CC_OPTION([if compiler supports -mbranch-protection=gcs],
>  LIBC_CONFIG_VAR([have-cc-gcs], [$libc_cv_cc_gcs])
>  LIBC_CONFIG_VAR([have-test-cc-gcs], [$libc_cv_test_cc_gcs])
>  
> +# Check if compiler supports -fno-fp-int-builtin-inexact
> +LIBC_TRY_CC_AND_TEST_CC_OPTION([if compiler supports -fno-fp-int-builtin-inexact],
> +  [-Werror -fno-fp-int-builtin-inexact],
> +  libc_cv_cc_no_fp_builtin_inexact,
> +  [libc_cv_cc_no_fp_builtin_inexact=-fno-fp-int-builtin-inexact],
> +  [libc_cv_cc_no_fp_builtin_inexact=],
> +  libc_cv_test_cc_no_fp_builtin_inexact,
> +  [libc_cv_test_cc_no_fp_builtin_inexact=-fno-fp-int-builtin-inexact],
> +  [libc_cv_test_cc_no_fp_builtin_inexact=])
> +LIBC_CONFIG_VAR([config-cflags-no-fp-builtin-inexact], [$libc_cv_cc_no_fp_builtin_inexact])
> +
>  # Check if linker supports GCS marking
>  LIBC_LINKER_FEATURE([-z gcs=always], [-Wl,-z,gcs=always],
>  		    [libc_cv_ld_gcs=yes], [libc_cv_ld_gcs=no])
> diff --git a/math/Makefile b/math/Makefile
> index d05108def1..f7a1d9016c 100644
> --- a/math/Makefile
> +++ b/math/Makefile
> @@ -1827,22 +1827,22 @@ CFLAGS-s_modff128.c += $(config-cflags-signaling-nans)
>  # These files rely on C23 semantics for avoiding "inexact" exceptions
>  # from rounding functions.  These settings can be removed when glibc
>  # builds with -std=gnu23 or later.
> -CFLAGS-s_fromfp.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpx.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfp.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpx.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpf.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpxf.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpf.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpxf.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpl.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpxl.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpl.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpxl.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpf128.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_fromfpxf128.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpf128.c += -fno-fp-int-builtin-inexact
> -CFLAGS-s_ufromfpxf128.c += -fno-fp-int-builtin-inexact
> +CFLAGS-s_fromfp.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpx.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfp.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpx.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpf.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpxf.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpf.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpxf.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpl.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpxl.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpl.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpxl.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpf128.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_fromfpxf128.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpf128.c += $(config-cflags-no-fp-builtin-inexact)
> +CFLAGS-s_ufromfpxf128.c += $(config-cflags-no-fp-builtin-inexact)
>  
>  $(addprefix $(objpfx),\
>  	    $(filter-out $(tests-static) $(libm-tests-vector),\