re PR fortran/32048 (max/min and NaN)

	PR fortran/32048

	* f95-lang.c (gfc_init_builtin_functions): Add declaration for
	__builtin_isnan.
	* trans-intrinsic.c (gfc_conv_intrinsic_minmax): Handled NaNs.

	* gfortran.dg/nan_1.f90: New test.

From-SVN: r127019

gcc/fortran/f95-lang.c

@@ -1004,6 +1004,11 @@ gfc_init_builtin_functions (void)
 		      "malloc", false);
   DECL_IS_MALLOC (built_in_decls[BUILT_IN_MALLOC]) = 1;
 
+  tmp = tree_cons (NULL_TREE, void_type_node, void_list_node);
+  ftype = build_function_type (integer_type_node, tmp);
+  gfc_define_builtin ("__builtin_isnan", ftype, BUILT_IN_ISNAN,
+		      "__builtin_isnan", true);
+
 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
   builtin_types[(int) ENUM] = VALUE;
 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN)		\

gcc/fortran/trans-intrinsic.c

@@ -1407,11 +1407,11 @@ gfc_conv_intrinsic_ttynam (gfc_se * se, gfc_expr * expr)
 /* Get the minimum/maximum value of all the parameters.
     minmax (a1, a2, a3, ...)
     {
-      if (a2 .op. a1)
+      if (a2 .op. a1 || isnan(a1))
         mvar = a2;
       else
         mvar = a1;
-      if (a3 .op. mvar)
+      if (a3 .op. mvar || isnan(mvar))
         mvar = a3;
       ...
       return mvar
@@ -1487,7 +1487,7 @@ gfc_conv_intrinsic_minmax (gfc_se * se, gfc_expr * expr, int op)
   elsecase = build2_v (MODIFY_EXPR, mvar, limit);
   for (i = 1, argexpr = argexpr->next; i < nargs; i++)
     {
-      tree cond;
+      tree cond, isnan;
 
       val = args[i]; 
 
@@ -1509,6 +1509,15 @@ gfc_conv_intrinsic_minmax (gfc_se * se, gfc_expr * expr, int op)
       thencase = build2_v (MODIFY_EXPR, mvar, convert (type, val));
 
       tmp = build2 (op, boolean_type_node, convert (type, val), limit);
+
+      /* FIXME: When the IEEE_ARITHMETIC module is implemented, the call to
+	 __builtin_isnan might be made dependent on that module being loaded,
+	 to help performance of programs that don't rely on IEEE semantics.  */
+      if (FLOAT_TYPE_P (TREE_TYPE (limit)))
+	{
+	  isnan = build_call_expr (built_in_decls[BUILT_IN_ISNAN], 1, limit);
+	  tmp = fold_build2 (TRUTH_OR_EXPR, boolean_type_node, tmp, isnan);
+	}
       tmp = build3_v (COND_EXPR, tmp, thencase, elsecase);
 
       if (cond != NULL_TREE)

gcc/testsuite/gfortran.dg/nan_1.f90

+! Test if MIN and MAX intrinsics behave correctly when passed NaNs
+! as arguments
+!
+! { dg-do run }
+!
+module aux
+  interface isnan
+    module procedure isnan_r
+    module procedure isnan_d
+  end interface isnan
+
+  interface isinf
+    module procedure isinf_r
+    module procedure isinf_d
+  end interface isinf
+contains
+
+  pure function isnan_r(x) result (isnan)
+    logical :: isnan
+    real, intent(in) :: x
+
+    isnan = (.not.(x == x))
+  end function isnan_r
+
+  pure function isnan_d(x) result (isnan)
+    logical :: isnan
+    double precision, intent(in) :: x
+
+    isnan = (.not.(x == x))
+  end function isnan_d
+
+  pure function isinf_r(x) result (isinf)
+    logical :: isinf
+    real, intent(in) :: x
+
+    isinf = (x > huge(x)) .or. (x < -huge(x))
+  end function isinf_r
+
+  pure function isinf_d(x) result (isinf)
+    logical :: isinf
+    double precision, intent(in) :: x
+
+    isinf = (x > huge(x)) .or. (x < -huge(x))
+  end function isinf_d
+end module aux
+
+program test
+  use aux
+  implicit none
+  real :: nan, large, inf
+
+  ! Create a NaN and check it
+  nan = 0
+  nan = nan / nan
+  if (nan == nan .or. nan > nan .or. nan < nan .or. nan >= nan &
+      .or. nan <= nan) call abort
+  if (isnan (2.d0) .or. (.not. isnan(nan)) .or. &
+      (.not. isnan(real(nan,kind=kind(2.d0))))) call abort
+
+  ! Create an INF and check it
+  large = huge(large)
+  inf = 2 * large
+  if (isinf(nan) .or. isinf(large) .or. .not. isinf(inf)) call abort
+  if (isinf(-nan) .or. isinf(-large) .or. .not. isinf(-inf)) call abort
+
+  ! Check that MIN and MAX behave correctly
+  if (max(2.0, nan) /= 2.0) call abort
+  if (min(2.0, nan) /= 2.0) call abort
+  if (max(nan, 2.0) /= 2.0) call abort
+  if (min(nan, 2.0) /= 2.0) call abort
+
+  if (max(2.d0, nan) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (min(2.d0, nan) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (max(nan, 2.d0) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (min(nan, 2.d0) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+
+  if (.not. isnan(min(nan,nan))) call abort
+  if (.not. isnan(max(nan,nan))) call abort
+
+  ! Same thing, with more arguments
+
+  if (max(3.0, 2.0, nan) /= 3.0) call abort
+  if (min(3.0, 2.0, nan) /= 2.0) call abort
+  if (max(3.0, nan, 2.0) /= 3.0) call abort
+  if (min(3.0, nan, 2.0) /= 2.0) call abort
+  if (max(nan, 3.0, 2.0) /= 3.0) call abort
+  if (min(nan, 3.0, 2.0) /= 2.0) call abort
+
+  if (max(3.d0, 2.d0, nan) /= 3.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (min(3.d0, 2.d0, nan) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (max(3.d0, nan, 2.d0) /= 3.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (min(3.d0, nan, 2.d0) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (max(nan, 3.d0, 2.d0) /= 3.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+  if (min(nan, 3.d0, 2.d0) /= 2.d0) call abort ! { dg-warning "Extension: Different type kinds" }
+
+  if (.not. isnan(min(nan,nan,nan))) call abort
+  if (.not. isnan(max(nan,nan,nan))) call abort
+  if (.not. isnan(min(nan,nan,nan,nan))) call abort
+  if (.not. isnan(max(nan,nan,nan,nan))) call abort
+  if (.not. isnan(min(nan,nan,nan,nan,nan))) call abort
+  if (.not. isnan(max(nan,nan,nan,nan,nan))) call abort
+
+  ! Large values, INF and NaNs
+  if (.not. isinf(max(large, inf))) call abort
+  if (isinf(min(large, inf))) call abort
+  if (.not. isinf(max(nan, large, inf))) call abort
+  if (isinf(min(nan, large, inf))) call abort
+  if (.not. isinf(max(large, nan, inf))) call abort
+  if (isinf(min(large, nan, inf))) call abort
+  if (.not. isinf(max(large, inf, nan))) call abort
+  if (isinf(min(large, inf, nan))) call abort
+
+  if (.not. isinf(min(-large, -inf))) call abort
+  if (isinf(max(-large, -inf))) call abort
+  if (.not. isinf(min(nan, -large, -inf))) call abort
+  if (isinf(max(nan, -large, -inf))) call abort
+  if (.not. isinf(min(-large, nan, -inf))) call abort
+  if (isinf(max(-large, nan, -inf))) call abort
+  if (.not. isinf(min(-large, -inf, nan))) call abort
+  if (isinf(max(-large, -inf, nan))) call abort
+
+end program test
+
+! { dg-final { cleanup-modules "aux" } }