Fortran: Allow IEEE_CLASS to identify signaling NaNs

We use the issignaling macro, present in some libc's (notably glibc),
when it is available. Compile all IEEE-related files in the library
(both C and Fortran sources) with -fsignaling-nans to ensure maximum
compatibility.

libgfortran/ChangeLog:

	PR fortran/82207
	* Makefile.am: Pass -fsignaling-nans for IEEE files.
	* Makefile.in: Regenerate.
	* ieee/ieee_helper.c: Use issignaling macro to recognized
	signaling NaNs.

gcc/testsuite/ChangeLog:

	PR fortran/82207
	* gfortran.dg/ieee/signaling_1.f90: New test.
	* gfortran.dg/ieee/signaling_1_c.c: New file.

2 files changed, 103 insertions, 0 deletions

diff --git a/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90 b/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90
new file mode 100644
index 0000000..a1403e6
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/ieee/signaling_1.f90
@@ -0,0 +1,89 @@
+! { dg-do run }
+! { dg-require-effective-target issignaling } */
+! { dg-additional-sources signaling_1_c.c }
+! { dg-options "-fsignaling-nans" }
+!
+program test
+  use, intrinsic :: iso_c_binding
+  use, intrinsic :: ieee_arithmetic
+  implicit none
+
+  interface
+    real(kind=c_float) function create_nansf () bind(c)
+      import :: c_float
+    end function
+
+    real(kind=c_double) function create_nans () bind(c)
+      import :: c_double
+    end function
+
+    real(kind=c_long_double) function create_nansl () bind(c)
+      import :: c_long_double
+    end function
+  end interface
+
+  real(kind=c_float) :: x
+  real(kind=c_double) :: y
+  real(kind=c_long_double) :: z
+
+  if (ieee_support_nan(x)) then
+    x = create_nansf()
+    if (ieee_class(x) /= ieee_signaling_nan) stop 100
+    if (.not. ieee_is_nan(x)) stop 101
+    if (ieee_is_negative(x)) stop 102
+    if (ieee_is_finite(x)) stop 103
+    if (ieee_is_normal(x)) stop 104
+    if (.not. ieee_unordered(x, x)) stop 105
+    if (.not. ieee_unordered(x, 1._c_float)) stop 106
+
+    x = ieee_value(y, ieee_quiet_nan)
+    if (ieee_class(x) /= ieee_quiet_nan) stop 107
+    if (.not. ieee_is_nan(x)) stop 108
+    if (ieee_is_negative(x)) stop 109
+    if (ieee_is_finite(x)) stop 110
+    if (ieee_is_normal(x)) stop 111
+    if (.not. ieee_unordered(x, x)) stop 112
+    if (.not. ieee_unordered(x, 1._c_double)) stop 113
+  end if
+
+  if (ieee_support_nan(y)) then
+    y = create_nans()
+    if (ieee_class(y) /= ieee_signaling_nan) stop 200
+    if (.not. ieee_is_nan(y)) stop 201
+    if (ieee_is_negative(y)) stop 202
+    if (ieee_is_finite(y)) stop 203
+    if (ieee_is_normal(y)) stop 204
+    if (.not. ieee_unordered(y, x)) stop 205
+    if (.not. ieee_unordered(y, 1._c_double)) stop 206
+
+    y = ieee_value(y, ieee_quiet_nan)
+    if (ieee_class(y) /= ieee_quiet_nan) stop 207
+    if (.not. ieee_is_nan(y)) stop 208
+    if (ieee_is_negative(y)) stop 209
+    if (ieee_is_finite(y)) stop 210
+    if (ieee_is_normal(y)) stop 211
+    if (.not. ieee_unordered(y, y)) stop 212
+    if (.not. ieee_unordered(y, 1._c_double)) stop 213
+  end if
+
+  if (ieee_support_nan(z)) then
+    z = create_nansl()
+    if (ieee_class(z) /= ieee_signaling_nan) stop 300
+    if (.not. ieee_is_nan(z)) stop 301
+    if (ieee_is_negative(z)) stop 302
+    if (ieee_is_finite(z)) stop 303
+    if (ieee_is_normal(z)) stop 304
+    if (.not. ieee_unordered(z, z)) stop 305
+    if (.not. ieee_unordered(z, 1._c_long_double)) stop 306
+
+    z = ieee_value(y, ieee_quiet_nan)
+    if (ieee_class(z) /= ieee_quiet_nan) stop 307
+    if (.not. ieee_is_nan(z)) stop 308
+    if (ieee_is_negative(z)) stop 309
+    if (ieee_is_finite(z)) stop 310
+    if (ieee_is_normal(z)) stop 311
+    if (.not. ieee_unordered(z, z)) stop 312
+    if (.not. ieee_unordered(z, 1._c_double)) stop 313
+  end if
+
+end program test
diff --git a/gcc/testsuite/gfortran.dg/ieee/signaling_1_c.c b/gcc/testsuite/gfortran.dg/ieee/signaling_1_c.c
new file mode 100644
index 0000000..ab19bb7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/ieee/signaling_1_c.c
@@ -0,0 +1,14 @@
+float create_nansf (void)
+{
+  return __builtin_nansf("");
+}
+
+double create_nans (void)
+{
+  return __builtin_nans("");
+}
+
+long double create_nansl (void)
+{
+  return __builtin_nansl("");
+}