[PATCH v3 11/19] x86: math: Use of __libgcc_cmp_return__ iff compiler supports it

[Adhemerval Zanella]

clang does not support '__attribute__ ((mode (__libgcc_cmp_return__)))',
so use a more close related type instead fo the default 'int'.
---
 config.h.in                   |  3 +++
 sysdeps/x86/configure         | 39 +++++++++++++++++++++++++++++++++++
 sysdeps/x86/configure.ac      | 18 ++++++++++++++++
 sysdeps/x86/fpu/sfp-machine.h | 10 ++++++++-
 4 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/config.h.in b/config.h.in
index 8a997f0d4b4..a7cc17df8ed 100644
--- a/config.h.in
+++ b/config.h.in
@@ -320,4 +320,7 @@
 /* Define if compiler allows add attribute after function declaration.  */
 #undef ATTR_AFTER_FUNC_DECL
 
+/* Define if compiler suport __attribute__ ((mode (__libgcc_cmp_return__))).  */
+#undef HAVE_X86_LIBGCC_CMP_RETURN_ATTR
+
 #endif
diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
index 2e95277f29e..ad205f69751 100644
--- a/sysdeps/x86/configure
+++ b/sysdeps/x86/configure
@@ -392,6 +392,45 @@ else
 
 fi
 
+
+conftest_code="
+int __gcc_CMPtype_GCC __attribute__ ((mode (__libgcc_cmp_return__)));
+"
+
+cat > conftest.c <<EOF
+$conftest_code
+EOF
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for __libgcc_cmp_return__ mode attribute support" >&5
+printf %s "checking for __libgcc_cmp_return__ mode attribute support... " >&6; }
+if test ${libc_cv_cc_x86_libgcc_cmp_return_attribute+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e)   if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $CFLAGS conftest.c -o conftest 1>&5'
+  { { eval echo "\"\$as_me\":${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 $ac_status = 0; }; }
+  then
+    libc_cv_cc_x86_libgcc_cmp_return_attribute=yes
+  else
+    libc_cv_cc_x86_libgcc_cmp_return_attribute=no
+  fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_x86_libgcc_cmp_return_attribute" >&5
+printf "%s\n" "$libc_cv_cc_x86_libgcc_cmp_return_attribute" >&6; }
+rm -f conftest*
+if test "$libc_cv_cc_x86_libgcc_cmp_return_attribute" = yes; then
+  printf "%s\n" "#define HAVE_X86_LIBGCC_CMP_RETURN_ATTR 1" >>confdefs.h
+
+else
+  printf "%s\n" "#define HAVE_X86_LIBGCC_CMP_RETURN_ATTR 0" >>confdefs.h
+
+fi
+
+
 if test "${libc_cv_cc_no_direct_extern_access}${libc_cv_test_cc_cflags_no_direct_extern_access}" = yes; then
   libc_cv_protected_data=no
 fi
diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
index f3888e6618b..e0500f21b4e 100644
--- a/sysdeps/x86/configure.ac
+++ b/sysdeps/x86/configure.ac
@@ -223,6 +223,24 @@ else
   AC_DEFINE(HAVE_X86_INLINE_TRUNC, 0)
 fi
 
+
+conftest_code="
+int __gcc_CMPtype_GCC __attribute__ ((mode (__libgcc_cmp_return__)));
+"
+dnl Check if CC support the __libgcc_cmp_return__ mode attribute
+LIBC_TRY_CC_COMMAND([for __libgcc_cmp_return__ mode attribute support],
+  [$conftest_code],
+  [$CFLAGS],
+  libc_cv_cc_x86_libgcc_cmp_return_attribute,
+  [libc_cv_cc_x86_libgcc_cmp_return_attribute=yes],
+  [libc_cv_cc_x86_libgcc_cmp_return_attribute=no])
+if test "$libc_cv_cc_x86_libgcc_cmp_return_attribute" = yes; then
+  AC_DEFINE(HAVE_X86_LIBGCC_CMP_RETURN_ATTR, 1)
+else
+  AC_DEFINE(HAVE_X86_LIBGCC_CMP_RETURN_ATTR, 0)
+fi
+
+
 dnl If the building compiler enables no direct external data access by
 dnl default, access to protected data in shared libraries from executables
 dnl must be compiled with no direct external data access.  If the testing
diff --git a/sysdeps/x86/fpu/sfp-machine.h b/sysdeps/x86/fpu/sfp-machine.h
index cbcedb8621e..9ef85c4e6c2 100644
--- a/sysdeps/x86/fpu/sfp-machine.h
+++ b/sysdeps/x86/fpu/sfp-machine.h
@@ -1,9 +1,17 @@
 /* Configure soft-fp for building sqrtf128.  Based on sfp-machine.h in
    libgcc, with soft-float and other irrelevant parts removed.  */
 
+#if HAVE_X86_LIBGCC_CMP_RETURN_ATTR
 /* The type of the result of a floating point comparison.  This must
    match `__libgcc_cmp_return__' in GCC for the target.  */
-typedef int __gcc_CMPtype __attribute__ ((mode (__libgcc_cmp_return__)));
+typedef int __gcc_CMPtype_GCC __attribute__ ((mode (__libgcc_cmp_return__)));
+#else
+# if defined __x86_64__ && defined __ILP32__
+typedef long long int __gcc_CMPtype;
+#else
+typedef long int __gcc_CMPtype;
+# endif
+#endif
 #define CMPtype __gcc_CMPtype
 
 #ifdef __x86_64__
-- 
2.43.0