[Bug ada/21573] 'Valid attribute on enumeration types with holes

["fw at deneb dot enyo dot de" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From fw at deneb dot enyo dot de  2005-05-14 19:35 -------
Subject: Re:  'Valid attribute on enumeration types with holes

* pinskia at gcc dot gnu dot org:

> ------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-14 19:09 -------
> It works for me on powerpc-darwin with "4.0.0 20050222".

I've looked at the trees generated by the following three-file test
case (in particular the tree dumps for bug2_p.adb), and they look
fine.  Maybe it's an i386 back end issue.

-- Run through gnatchop

with Ada.Unchecked_Conversion;
with Ada.Text_IO; use Ada.Text_IO;
with Bug2_P; use Bug2_P;

procedure Bug2 is
   function Convert is new Ada.Unchecked_Conversion (N, T);

begin
   if V (Convert (0)) then
      Put_Line ("FAIL");
   else
      Put_Line ("SUCCESS");
   end if;
end Bug2;

package Bug2_P is

   type T is (A, B, C, D);
   for T'Size use 8;
   for T use (A => 2, B => 3, C => 5, D => 7);
   type N is mod 2**8;

   function V (X : T) return Boolean;

end Bug2_P;

package body Bug2_P is

   function V (X : T) return Boolean is
   begin
      return X'Valid;
   end V;

end Bug2_P;

-- End

The i386 assembly code looks like this:

	.type	bug2_p__tRP, @function
bug2_p__tRP:
.LFB4:
	pushl	%ebp
.LCFI0:
	movl	%esp, %ebp
.LCFI1:
	subl	$8, %esp
.LCFI2:
	movb	8(%ebp), %al
	movb	12(%ebp), %dl
	cmpb	$3, %al
	je	.L4
	jb	.L3
	cmpb	$5, %al
	je	.L5
	cmpb	$7, %al
	je	.L13
	testb	%dl, %dl
	jne	.L8
	movl	$-1, %eax
	leave
	ret
	.p2align 4,,15
.L3:
	xorl	%eax, %eax
	leave
	ret
        [...]

I'm not very good at reading AT&T syntax, but it appears that for a
first argument of 0, the branch to .L3 is taken, which returns 0
(instead of the expected -1).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21573