[Bug target/58416] Incorrect x87-based union copying code

["ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58416

--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Richard Biener from comment #2)

> where *movdf_internal simply doesn't properly preserve sNaN.
> 
> It looks wrong for DFmode move instructions to not preserve a IEEE defined
> flag.  I suppose it would be also wrong to not preserve the exact bit pattern
> (think of canonicalizing NaNs).

As said in PR57484, comment 11:

On an x86 target using the legacy x87 instructions and the 80-bit registers, a
load of a 64-bit or 32-bit value in memory into the 80-bit registers counts as
a format conversion and an signaling NaN input will turn into a quiet NaN in
the register format.
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From: "valeryweber at hotmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/58434] New: no automatic deallocation with trunk
Date: Mon, 16 Sep 2013 13:22:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idX434

            Bug ID: 58434
           Summary: no automatic deallocation with trunk
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: valeryweber at hotmail dot com

Dear All
I noticed a changed of behavior between 4.8.1 and trunk.
While the following code produde no memory leaks with 4.8.1 it does with
the trunk. Is that a bug?
v


cat tmp.f90
module mod
  type t
     integer,allocatable,dimension(:)::i
  end type t
end module mod
program main
  use mod
  type(t) :: a
  allocate(a%i(10000))
end program main
gfortran-trunk -g tmp.f90
valgrind ./a.out
=\x13501== Memcheck, a memory error detector
=\x13501== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al.
=\x13501== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info
=\x13501== Command: ./a.out
=\x13501==\x13501==\x13501== HEAP SUMMARY:
=\x13501==     in use at exit: 40,000 bytes in 1 blocks
=\x13501==   total heap usage: 18 allocs, 17 frees, 43,688 bytes allocated
=\x13501==\x13501== LEAK SUMMARY:
=\x13501==    definitely lost: 0 bytes in 0 blocks
=\x13501==    indirectly lost: 0 bytes in 0 blocks
=\x13501==      possibly lost: 0 bytes in 0 blocks
=\x13501==    still reachable: 40,000 bytes in 1 blocks
=\x13501==         suppressed: 0 bytes in 0 blocks
=\x13501== Rerun with --leak-check=full to see details of leaked memory
=\x13501==\x13501== For counts of detected and suppressed errors, rerun with: -v
=\x13501== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)
gfortran-4.8.1 -g tmp.f90
valgrind ./a.out
=\x13508== Memcheck, a memory error detector
=\x13508== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al.
=\x13508== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info
=\x13508== Command: ./a.out
=\x13508==\x13508==\x13508== HEAP SUMMARY:
=\x13508==     in use at exit: 0 bytes in 0 blocks
=\x13508==   total heap usage: 18 allocs, 18 frees, 43,664 bytes allocated
=\x13508==\x13508== All heap blocks were freed -- no leaks are possible
=\x13508==\x13508== For counts of detected and suppressed errors, rerun with: -v
=\x13508== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)