[gcc(refs/users/aoliva/heads/testme)] [libstdc++] [testsuite] xfail double-prec from_chars for ldbl

[gcc(refs/users/aoliva/heads/testme)] [libstdc++] [testsuite] xfail double-prec from_chars for ldbl

[Alexandre Oliva]

https://gcc.gnu.org/g:909ba6af9ebb9f8069e70f1245fa440db3d766d0

commit 909ba6af9ebb9f8069e70f1245fa440db3d766d0
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Fri May 5 06:28:16 2023 -0300

    [libstdc++] [testsuite] xfail double-prec from_chars for ldbl
    
    When long double is wider than double, but from_chars is implemented
    in terms of double, tests that involve the full precision of long
    double are expected to fail.  Mark them as such on aarch64-*-vxworks.
    
    
    for  libstdc++-v3/ChangeLog
    
            * testsuite/20_util/from_chars/4.cc: Skip long double test06
            on aarch64-vxworks.
            * testsuite/20_util/to_chars/long_double.cc: Xfail run on
            aarch64-vxworks.

Diff:
---
 libstdc++-v3/testsuite/20_util/from_chars/4.cc         | 3 ++-
 libstdc++-v3/testsuite/20_util/to_chars/long_double.cc | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/20_util/from_chars/4.cc b/libstdc++-v3/testsuite/20_util/from_chars/4.cc
index dd55690eb65..c3594f9014b 100644
--- a/libstdc++-v3/testsuite/20_util/from_chars/4.cc
+++ b/libstdc++-v3/testsuite/20_util/from_chars/4.cc
@@ -18,6 +18,7 @@
 // <charconv> is supported in C++14 as a GNU extension
 // { dg-do run { target c++14 } }
 // { dg-add-options ieee }
+// { dg-additional-options "-DSKIP_LONG_DOUBLE" { target aarch64-*-vxworks* } }
 
 #include <charconv>
 #include <string>
@@ -354,7 +355,7 @@ test06()
 {
   test_max_mantissa<float, unsigned long>();
   test_max_mantissa<double, unsigned long long>();
-#ifdef __GLIBCXX_TYPE_INT_N_0
+#if defined __GLIBCXX_TYPE_INT_N_0 && !defined SKIP_LONG_DOUBLE
   test_max_mantissa<long double, unsigned __GLIBCXX_TYPE_INT_N_0>();
 #endif
 }
diff --git a/libstdc++-v3/testsuite/20_util/to_chars/long_double.cc b/libstdc++-v3/testsuite/20_util/to_chars/long_double.cc
index 880c9802187..263144bd42c 100644
--- a/libstdc++-v3/testsuite/20_util/to_chars/long_double.cc
+++ b/libstdc++-v3/testsuite/20_util/to_chars/long_double.cc
@@ -34,6 +34,10 @@
 // more portable and robust to differences in system printf behavior.
 // { dg-xfail-run-if "Non-conforming printf (see PR98384)" { *-*-solaris* *-*-darwin* } }
 
+// On systems that use double-precision from_chars for long double,
+// this is expected to fail.
+// { dg-xfail-run-if "from_chars limited to double-precision" { aarch64-*-vxworks* } }
+
 // { dg-require-effective-target ieee_floats }
 // { dg-require-effective-target size32plus }
 // { dg-require-cmath "" }