[Bug target/39082] New: union with long double doesn't follow x86-64 psABI

[Bug target/39082] New: union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

x86-64 psABI says:

The 64-bit mantissa of arguments of type {long double
belongs to class X87, the 16-bit exponent plus 6 bytes of padding
belongs to class X87UP.

...

If one of the classes is X87, X87UP, COMPLEX\_X87 class,
MEMORY is used as class.

But I got

[hjl@gnu-6 avx-abi]$ cat u4.i
union sse2
{
  int i;
  long double x;
};

long double
bar2 (union sse2 x)
{
  return x.x;
}

long double
foo2 (long double x)
{
  union sse2 y;
  y.x = x;
  return bar2 (y);
}
[hjl@gnu-6 avx-abi]$ gcc -S  u4.i -O -fno-asynchronous-unwind-tables
[hjl@gnu-6 avx-abi]$ cat u4.s
        .file   "u4.i"
        .text
.globl bar2
        .type   bar2, @function
bar2:
        movq    %rdi, -24(%rsp)
        movq    %xmm0, -16(%rsp)
        fldt    -24(%rsp)
        ret
        .size   bar2, .-bar2
.globl foo2
        .type   foo2, @function
foo2:
        subq    $24, %rsp
        movq    32(%rsp), %rax
        movl    40(%rsp), %edx
        movq    %rax, (%rsp)
        movl    %edx, 8(%rsp)
        movq    (%rsp), %rdi
        movq    8(%rsp), %xmm0
        call    bar2
        addq    $24, %rsp
        ret
        .size   foo2, .-foo2

Dave, does icc follow psABI?


-- 
           Summary: union with long double doesn't follow x86-64 psABI
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl dot tools at gmail dot com
GCC target triplet: x86_64-*-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[Joey dot ye at intel dot com]

------- Comment #1 from Joey dot ye at intel dot com  2009-02-04 02:17 -------
GCC doesn't follow x86-64 psABI on this case.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #2 from hjl dot tools at gmail dot com  2009-02-04 02:32 -------
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00137.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ubizjak at gmail dot com
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2009-
                   |                            |02/msg00137.html
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-02-04 02:32:35
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #3 from hjl dot tools at gmail dot com  2009-02-06 14:33 -------
The updated patch is at

http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00259.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|http://gcc.gnu.org/ml/gcc-  |http://gcc.gnu.org/ml/gcc-
                   |patches/2009-               |patches/2009-
                   |02/msg00137.html            |02/msg00259.html
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #4 from hjl dot tools at gmail dot com  2009-02-10 21:44 -------
The updated patch is at

http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00477.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|http://gcc.gnu.org/ml/gcc-  |http://gcc.gnu.org/ml/gcc-
                   |patches/2009-               |patches/2009-
                   |02/msg00259.html            |02/msg00477.html


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[mmitchel at gcc dot gnu dot org]

------- Comment #5 from mmitchel at gcc dot gnu dot org  2009-02-11 01:45 -------
Is this a regression?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #6 from hjl dot tools at gmail dot com  2009-02-13 15:51 -------
I checked gcc 3.4.6. The bug is there.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[mmitchel at gcc dot gnu dot org]

------- Comment #7 from mmitchel at gcc dot gnu dot org  2009-02-13 16:41 -------
In that case, this isn't a high-priority bug.  That doesn't mean that it can't
be fixed before 4.4; that's up to the x86 maintainers.  But, it shouldn't block
the release.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl at gcc dot gnu dot org]

------- Comment #8 from hjl at gcc dot gnu dot org  2009-02-18 02:16 -------
Subject: Bug 39082

Author: hjl
Date: Wed Feb 18 02:16:03 2009
New Revision: 144257

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=144257
Log:
gcc/

2009-02-17  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/39082
        * c.opt (Wabi): Support C and ObjC.
        (Wpsabi): New.

        * c-opts.c (c_common_handle_option): Handle OPT_Wabi.

        * config/i386/i386.c (classify_argument): Warn once about the ABI
        change when passing union with long double.

        * doc/invoke.texi: Update -Wabi for warning psABI changes.

gcc/testsuite/

2009-02-17  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/39082
        * g++.dg/compat/struct-layout-1_generate.c (dg_options): Add
        -Wno-abi for x86.
        * gcc.dg/compat/struct-layout-1_generate.c (dg_options): Likewise.

        * gcc.target/i386/pr39082-1.c: New.

        * gcc.target/x86_64/abi/abi-x86_64.exp (additional_flags): Add
        -Wno-abi.

        * gcc.target/x86_64/abi/args.h (XMM_T): Add _m64 and _m128 if
        CHECK_M64_M128 is defined.
        (check_f_arguments): Add "do".
        (check_vector_arguments): New.
        (check_m64_arguments): Likewise.
        (check_m128_arguments): Likewise.

        * gcc.target/x86_64/abi/defines.h: Include <xmmintrin.h>.
        (CHECK_M64_M128): Define.

        * gcc.target/x86_64/abi/test_m64m128_returning.c: New.  Based
        on abitest.
        * gcc.target/x86_64/abi/test_passing_m64m128.c: Likewise.

        * gcc.target/x86_64/abi/test_passing_structs.c: Define __m128
        tests only if CHECK_M64_M128 is defined.

        * gcc.target/x86_64/abi/test_passing_structs.c (m128_struct): New.
        (m128_2_struct): Likewise.
        (check_struct_passing5): Likewise.
        (check_struct_passing6): Likewise.
        (main): Test struct with __m128 if CHECK_M64_M128 is defined.

        * gcc.target/x86_64/abi/test_passing_unions.c (un4): New.
        (un5): Likewise.
        (check_union_passing4): Likewise.
        (main): Test union with __m128 if CHECK_M64_M128 is defined.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr39082-1.c
    trunk/gcc/testsuite/gcc.target/x86_64/abi/test_m64m128_returning.c
    trunk/gcc/testsuite/gcc.target/x86_64/abi/test_passing_m64m128.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-opts.c
    trunk/gcc/c.opt
    trunk/gcc/config/i386/i386.c
    trunk/gcc/doc/invoke.texi
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/compat/struct-layout-1_generate.c
    trunk/gcc/testsuite/gcc.dg/compat/struct-layout-1_generate.c
    trunk/gcc/testsuite/gcc.target/x86_64/abi/abi-x86_64.exp
    trunk/gcc/testsuite/gcc.target/x86_64/abi/args.h
    trunk/gcc/testsuite/gcc.target/x86_64/abi/defines.h
    trunk/gcc/testsuite/gcc.target/x86_64/abi/test_passing_structs.c
    trunk/gcc/testsuite/gcc.target/x86_64/abi/test_passing_unions.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #9 from hjl dot tools at gmail dot com  2009-02-18 04:40 -------
Fixed.


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[ebotcazou at gcc dot gnu dot org]

------- Comment #10 from ebotcazou at gcc dot gnu dot org  2009-02-18 09:51 -------
Please make sure the warning is issued only for appropriate languages (it is
not
needed in Ada for example and the wording doesn't make sense).  TIA.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #11 from hjl dot tools at gmail dot com  2009-02-18 14:08 -------
(In reply to comment #10)
> Please make sure the warning is issued only for appropriate languages (it is
> not
> needed in Ada for example and the wording doesn't make sense).  TIA.
> 

I believe that warning is turned on for C ObjC C++ ObjC++ only. Did
you run into any problems?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[ebotcazou at gcc dot gnu dot org]

------- Comment #12 from ebotcazou at gcc dot gnu dot org  2009-02-18 14:38 -------
> I believe that warning is turned on for C ObjC C++ ObjC++ only.

Wrong.

spgn_numerics.ads: In function 'Test_Gip_Stat':
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
test_gip_stat.adb:13:09: warning: variable "GS2" is never read and never
assigned
expr.ads:699: note: The ABI of passing union with long double has changed in
GCC 4.4
expr-arithmetic_expr.adb:1740:07: warning: variable "Local_Expr" is never read
and never assigned
expr-named_entity_ref.adb:299:12: warning: variable "Junk" is read but never
assigned
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
expr.ads:699: note: The ABI of passing union with long double has changed in
GCC 4.4
expr.ads:699: note: The ABI of passing union with long double has changed in
GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4
spgn_numerics.ads:25: note: The ABI of passing union with long double has
changed in GCC 4.4

[...]


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[ebotcazou at gcc dot gnu dot org]

------- Comment #13 from ebotcazou at gcc dot gnu dot org  2009-02-18 14:51 -------
Created an attachment (id=17325)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17325&action=view)
Ada testcase

(botcazou@red) ~ $ gcc -S p.ads
p.ads:16: note: The ABI of passing union with long double has changed in GCC
4.4


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #14 from hjl dot tools at gmail dot com  2009-02-18 15:10 -------
(In reply to comment #12)
> > I believe that warning is turned on for C ObjC C++ ObjC++ only.
> 
> Wrong.

A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00834.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082

[Bug target/39082] union with long double doesn't follow x86-64 psABI

[hjl dot tools at gmail dot com]

------- Comment #15 from hjl dot tools at gmail dot com  2009-02-18 17:43 -------
(In reply to comment #13)
> Created an attachment (id=17325)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17325&action=view) [edit]
> Ada testcase
> 
> (botcazou@red) ~ $ gcc -S p.ads
> p.ads:16: note: The ABI of passing union with long double has changed in GCC
> 4.4
> 

A new patch is at

http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00855.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39082