Fortran: xfail signaling NaN testcases on x87

The ABI for x87 and x86-32 is not suitable for passing around
signaling NaNs in the way IEEE expects. See for example discussion
in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57484

gcc/testsuite/ChangeLog:

	* gfortran.dg/ieee/signaling_1.f90: xfail on x87.
	* gfortran.dg/ieee/signaling_2.f90: xfail on x87.

3 files changed, 50 insertions, 4 deletions

diff --git a/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90 b/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90
index 93c8e18..94ece3a 100644
--- a/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90
+++ b/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90
@@ -1,8 +1,10 @@
-! { dg-do run }
+! { dg-do run { xfail { { i?86-*-* x86_64-*-* } && ilp32 } } }
+! x87 / x86-32 ABI is unsuitable for signaling NaNs
+!
 ! { dg-require-effective-target issignaling } */
 ! { dg-additional-sources signaling_1_c.c }
 ! { dg-additional-options "-w" }
-! the -w option is needed to make cc1 not report a warning for 
+! The -w option is needed to make cc1 not report a warning for 
 ! the -fintrinsic-modules-path option passed by ieee.exp
 !
 program test
diff --git a/gcc/testsuite/gfortran.dg/ieee/signaling_2.f90 b/gcc/testsuite/gfortran.dg/ieee/signaling_2.f90
index e7e7a4a..ff37ab6 100644
--- a/gcc/testsuite/gfortran.dg/ieee/signaling_2.f90
+++ b/gcc/testsuite/gfortran.dg/ieee/signaling_2.f90
@@ -1,8 +1,10 @@
-! { dg-do run }
+! { dg-do run { xfail { { i?86-*-* x86_64-*-* } && ilp32 } } }
+! x87 / x86-32 ABI is unsuitable for signaling NaNs
+!
 ! { dg-require-effective-target issignaling } */
 ! { dg-additional-sources signaling_2_c.c }
 ! { dg-additional-options "-w" }
-! the -w option is needed to make cc1 not report a warning for
+! The -w option is needed to make cc1 not report a warning for
 ! the -fintrinsic-modules-path option passed by ieee.exp
 !
 program test
diff --git a/gcc/testsuite/gfortran.dg/ieee/signaling_3.f90 b/gcc/testsuite/gfortran.dg/ieee/signaling_3.f90
new file mode 100644
index 0000000..45bd9c35
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/ieee/signaling_3.f90
@@ -0,0 +1,42 @@
+! { dg-do run }
+!
+program test
+  use, intrinsic :: iso_c_binding
+  use, intrinsic :: ieee_arithmetic
+  implicit none
+
+  real(kind=c_float) :: x
+  real(kind=c_double) :: y
+  real(kind=c_long_double) :: z
+
+  if (ieee_support_nan(x)) then
+    x = ieee_value(x, ieee_signaling_nan)
+    if (ieee_class(x) /= ieee_signaling_nan) stop 100
+    if (.not. ieee_is_nan(x)) stop 101
+
+    x = ieee_value(x, ieee_quiet_nan)
+    if (ieee_class(x) /= ieee_quiet_nan) stop 103
+    if (.not. ieee_is_nan(x)) stop 104
+  end if
+
+  if (ieee_support_nan(y)) then
+    y = ieee_value(y, ieee_signaling_nan)
+    if (ieee_class(y) /= ieee_signaling_nan) stop 100
+    if (.not. ieee_is_nan(y)) stop 101
+
+    y = ieee_value(y, ieee_quiet_nan)
+    if (ieee_class(y) /= ieee_quiet_nan) stop 103
+    if (.not. ieee_is_nan(y)) stop 104
+  end if
+
+  if (ieee_support_nan(z)) then
+    z = ieee_value(z, ieee_signaling_nan)
+    if (ieee_class(z) /= ieee_signaling_nan) stop 100
+    if (.not. ieee_is_nan(z)) stop 101
+
+    z = ieee_value(z, ieee_quiet_nan)
+    if (ieee_class(z) /= ieee_quiet_nan) stop 103
+    if (.not. ieee_is_nan(z)) stop 104
+  end if
+
+end program test