[Bug target/35657] New: TDmode isn't aligned at 128bit when passing to a function

[Bug target/35657] New: TDmode isn't aligned at 128bit when passing to a function

[hjl dot tools at gmail dot com]

ix86_function_arg_boundary returns PARM_BOUNDARY for TDmode
for ia32. Should it return 128bit? The psABI isn't clear on
it. I think it should be aligned at 128bit.


-- 
           Summary: TDmode isn't aligned at 128bit when passing to a
                    function
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl dot tools at gmail dot com
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] TDmode isn't aligned at 128bit when passing to a function

[ubizjak at gmail dot com]

------- Comment #1 from ubizjak at gmail dot com  2008-03-21 20:53 -------
(In reply to comment #0)
> ix86_function_arg_boundary returns PARM_BOUNDARY for TDmode
> for ia32. Should it return 128bit? The psABI isn't clear on
> it. I think it should be aligned at 128bit.

Yes, because it is moved to/from XMM registers. Currently, this exact problem
is handled by a specialization code in ix86_expand_vector_move that forces
unaligned instructions for TDmode memory moves via
ix86_expand_vector_move_misalign.

Please note that we have to be compatible with SSE x86 and non-SSE x86 code, so
TDmode can't be passed in XMM registers on x86_32 targets.

I'd wait for psABI to clear situation w.r.t to alignment first.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] TDmode isn't aligned at 128bit when passing to a function

[hjl dot tools at gmail dot com]

------- Comment #2 from hjl dot tools at gmail dot com  2008-03-22 00:27 -------
It is a question how TDmode should be aligned on stack when
passing to a function. I will ask it on the ia32 psABI group.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] TDmode isn't aligned at 128bit when passing to a function

[hjl dot tools at gmail dot com]

------- Comment #3 from hjl dot tools at gmail dot com  2008-03-25 00:42 -------
This patch will align DFP to its natural boundary.

Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c      (revision 1917)
+++ gcc/config/i386/i386.c      (working copy)
@@ -4609,7 +4609,8 @@ ix86_function_arg_boundary (enum machine
     align = GET_MODE_ALIGNMENT (mode);
   if (align < PARM_BOUNDARY)
     align = PARM_BOUNDARY;
-  if (!TARGET_64BIT)
+  /* Decimal floating point is aligned to its natural boundary.  */
+  if (!TARGET_64BIT && !VALID_DFP_MODE_P (mode))
     {
       /* i386 ABI defines all arguments to be 4 byte aligned.  We have to
         make an exception for SSE modes since these require 128bit


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] TDmode isn't aligned at 128bit when passing to a function

[hjl at gcc dot gnu dot org]

------- Comment #4 from hjl at gcc dot gnu dot org  2008-03-27 18:53 -------
Subject: Bug 35657

Author: hjl
Date: Thu Mar 27 18:52:18 2008
New Revision: 133649

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=133649
Log:
2008-03-27  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/35657
        * config/i386/i386.c (ix86_function_arg_boundary): Align
        decimal floating point to its natural boundary.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] TDmode isn't aligned at 128bit when passing to a function

[hjl at gcc dot gnu dot org]

------- Comment #5 from hjl at gcc dot gnu dot org  2008-03-27 18:56 -------
Subject: Bug 35657

Author: hjl
Date: Thu Mar 27 18:55:36 2008
New Revision: 133651

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=133651
Log:
2008-03-27  H.J. Lu  <hongjiu.lu@intel.com>

        Backport from mainline:
        2008-03-27  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/35657
        * config/i386/i386.c (ix86_function_arg_boundary): Align
        decimal floating point to its natural boundary.

Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/config/i386/i386.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] TDmode isn't aligned at 128bit when passing to a function

[hjl dot tools at gmail dot com]

------- Comment #6 from hjl dot tools at gmail dot com  2008-03-27 19:05 -------
Fixed.


-- 

hjl dot tools at gmail dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] [4.3] TDmode isn't aligned at 128bit when passing to a function

[ubizjak at gmail dot com]

-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-04-29 18:06:55
               date|                            |
   Target Milestone|---                         |4.3.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] [4.3] TDmode isn't aligned at 128bit when passing to a function

[ubizjak at gmail dot com]

------- Comment #7 from ubizjak at gmail dot com  2008-04-29 18:06 -------
The alignment of TDmode is not yet decided, see
http://groups.google.com/group/ia32-abi/browse_thread/thread/fc6db344b62dea76

Reopened as P1 bug, blocking 4.3.1 release, as per suggestion in
http://gcc.gnu.org/ml/gcc-patches/2008-04/msg02135.html


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |blocker
             Status|RESOLVED                    |UNCONFIRMED
           Keywords|                            |ABI
           Priority|P3                          |P1
         Resolution|FIXED                       |
            Summary|TDmode isn't aligned at     |[4.3] TDmode isn't aligned
                   |128bit when passing to a    |at 128bit when passing to a
                   |function                    |function


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] [4.3] Alignments of DFP types aren't consistent

[hjl dot tools at gmail dot com]

------- Comment #8 from hjl dot tools at gmail dot com  2008-04-29 18:44 -------
On IA32, all 8 byte types should be aligned at 4 byte and 16byte types
should be aligned at 16 byte. The only discrepancy is alignment of
8byte DFP type, _Decimal64. Gcc aligns it at 8 byte. But we should
treat its alignment like double.


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.3] TDmode isn't aligned  |[4.3] Alignments of DFP
                   |at 128bit when passing to a |types aren't consistent
                   |function                    |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] [4.3] Alignments of DFP types aren't consistent

[hjl dot tools at gmail dot com]

------- Comment #9 from hjl dot tools at gmail dot com  2008-04-30 20:55 -------
It turns out that __m64 is aligned to 4 byte in the outgoing
parameter block and 8 byte elsewhere. We want _Decimal64 to be
consistent with __m64, not double/long long.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] Alignments of DFP types aren't consistent

[hjl dot tools at gmail dot com]

------- Comment #10 from hjl dot tools at gmail dot com  2008-05-01 14:14 -------
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2008-05/msg00035.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |hjl dot tools at gmail dot
                   |dot org                     |com
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2008-
                   |                            |05/msg00035.html
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-04-29 18:06:55         |2008-05-01 14:14:56
               date|                            |
            Summary|[4.3] Alignments of DFP     |Alignments of DFP types
                   |types aren't consistent     |aren't consistent


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] Alignments of DFP types aren't consistent

[hjl dot tools at gmail dot com]

------- Comment #11 from hjl dot tools at gmail dot com  2008-05-05 22:49 -------
An updated patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2008-05/msg00271.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] Alignments of DFP types aren't consistent

[hjl at gcc dot gnu dot org]

------- Comment #12 from hjl at gcc dot gnu dot org  2008-05-06 15:41 -------
Subject: Bug 35657

Author: hjl
Date: Tue May  6 15:41:08 2008
New Revision: 134987

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=134987
Log:
2008-05-06  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/35657
        * config/i386/i386.c (contains_128bit_aligned_vector_p): Renamed
        to ...
        (contains_aligned_value_p): This.  Handle _Decimal128.
        (ix86_function_arg_boundary): Only align _Decimal128 to its
        natural boundary and handle it properly.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] Alignments of DFP types aren't consistent

[hjl at gcc dot gnu dot org]

------- Comment #13 from hjl at gcc dot gnu dot org  2008-05-08 19:12 -------
Subject: Bug 35657

Author: hjl
Date: Thu May  8 19:11:23 2008
New Revision: 135089

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=135089
Log:
2008-05-08  H.J. Lu  <hongjiu.lu@intel.com>

        Backport from mainline:
        2008-05-06  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/35657
        * config/i386/i386.c (contains_128bit_aligned_vector_p): Renamed
        to ...
        (contains_aligned_value_p): This.  Handle _Decimal128.
        (ix86_function_arg_boundary): Only align _Decimal128 to its
        natural boundary and handle it properly.

Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/config/i386/i386.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657

[Bug target/35657] Alignments of DFP types aren't consistent

[hjl dot tools at gmail dot com]

------- Comment #14 from hjl dot tools at gmail dot com  2008-05-08 19:12 -------
Fixed.


-- 

hjl dot tools at gmail dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35657