[PATCH] PR fortran/96711 - ICE on NINT() Function

[Harald Anlauf]

When rounding a real to integer(16) an ICE happened due to an unhandled
case in build_round_expr.  The attached patch add a special case for this.

I had to change a fold_convert to a convert (which seems to be frontend
specific stuff), otherwise I would get errors from the generated GIMPLE.
Does anybody know if this could produce problems elsewhere?
I'm open to other / better solutions.

Anyway, the patch does regtest cleanly on x86_64-pc-linux-gnu.

OK for master?

Thanks,
Harald


PR fortran/96711 - ICE with NINT() for integer(16) result

When rounding a real to the nearest integer, temporarily convert the real
argument to a longer real kind when the result is of type/kind integer(16).

gcc/fortran/ChangeLog:

        * trans-intrinsic.c (build_round_expr): Use temporary with
        appropriate kind for conversion before rounding to nearest
        integer when the result precision is 128 bits.

gcc/testsuite/ChangeLog:

        * gfortran.dg/pr96711.f90: New test.


diff --git a/gcc/fortran/trans-intrinsic.c b/gcc/fortran/trans-intrinsic.c
index 2483f016d8e..32fe9886c57 100644
--- a/gcc/fortran/trans-intrinsic.c
+++ b/gcc/fortran/trans-intrinsic.c
@@ -395,11 +395,24 @@ build_round_expr (tree arg, tree restype)
     fn = builtin_decl_for_precision (BUILT_IN_LROUND, argprec);
   else if (resprec <= LONG_LONG_TYPE_SIZE)
     fn = builtin_decl_for_precision (BUILT_IN_LLROUND, argprec);
+  else if (resprec >= argprec && resprec == 128)
+    {
+      /* Search for a real kind suitable as temporary for conversion.  */
+      int kind = -1;
+      for (int i = 0; kind < 0 && gfc_real_kinds[i].kind != 0; i++)
+	if (gfc_real_kinds[i].mode_precision >= resprec)
+	  kind = gfc_real_kinds[i].kind;
+      if (kind < 0)
+	gfc_internal_error ("Could not find real kind with at least %d bits",
+			    resprec);
+      arg = fold_convert (gfc_float128_type_node, arg);
+      fn = gfc_builtin_decl_for_float_kind (BUILT_IN_ROUND, kind);
+    }
   else
     gcc_unreachable ();

-  return fold_convert (restype, build_call_expr_loc (input_location,
-						 fn, 1, arg));
+  return convert (restype, build_call_expr_loc (input_location,
+						fn, 1, arg));
 }


diff --git a/gcc/testsuite/gfortran.dg/pr96711.f90 b/gcc/testsuite/gfortran.dg/pr96711.f90
new file mode 100644
index 00000000000..c6534713b52
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr96711.f90
@@ -0,0 +1,18 @@
+! { dg-do compile }
+! { dg-require-effective-target fortran_integer_16 }
+! { dg-require-effective-target fortran_real_16 }
+!
+! PR fortran/96711 - ICE on NINT() Function
+
+program p
+  implicit none
+  integer(16) :: m
+  real(8)     :: x
+  real(16)    :: y
+  x = 2 / epsilon (x)
+  y = 2 / epsilon (y)
+  m = nint (x, kind(m))
+  print *, m
+  m = nint (y, kind(m))
+  print *, m
+end program