[Bug testsuite/38151] New: tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[Bug testsuite/38151] New: tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

The gcc.dg-struct-layout-1/t028 test fails at -m64 on i686-apple-darwin9. The 
failure is due to line...

TCI(2848,unsigned int a;_Complex int atal1 b;struct{}atpaal
c[1];,F(2848,a,4027477739U,855699588U)F(2848,b,CINT(723419448,-218144346),CINT(-1673573213,131753020)))

in t028_test.h. Deleting this line allows the remaining t028 testcases to pass
the execution test.


-- 
           Summary: tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on
                    i686-apple-darwin9
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: howarth at nitro dot med dot uc dot edu
 GCC build triplet: i686-apple-darwin9
  GCC host triplet: i686-apple-darwin9
GCC target triplet: i686-apple-darwin9


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #1 from howarth at nitro dot med dot uc dot edu  2008-11-16 02:57 -------
Created an attachment (id=16694)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16694&action=view)
preprocessed source for t028_main.i


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #3 from howarth at nitro dot med dot uc dot edu  2008-11-16 02:59 -------
Created an attachment (id=16696)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16696&action=view)
preprocessed source for t028_x.i


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #2 from howarth at nitro dot med dot uc dot edu  2008-11-16 02:58 -------
Created an attachment (id=16695)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16695&action=view)
assembly file for t028_main.s at -m64 on i686-apple-darwin9


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #4 from howarth at nitro dot med dot uc dot edu  2008-11-16 03:00 -------
Created an attachment (id=16697)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16697&action=view)
assembly file for t028_x.s at -m64 on i686-apple-darwin9


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #6 from howarth at nitro dot med dot uc dot edu  2008-11-16 03:01 -------
Created an attachment (id=16699)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16699&action=view)
assembly file for t028_y.s at -m64 on i686-apple-darwin9


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #5 from howarth at nitro dot med dot uc dot edu  2008-11-16 03:00 -------
Created an attachment (id=16698)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16698&action=view)
preprocessed source for t028_y.i


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #7 from howarth at nitro dot med dot uc dot edu  2008-11-16 03:03 -------
Attached preprocessed source files and assembly files created with...

/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/xgcc
-B/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/ 
-I/sw/src/fink.build/gcc44-4.3.999-20081115/gcc-4.4-20081115/gcc/testsuite/gcc.dg/compat
-mno-mmx -fno-common -DSKIP_DECIMAL_FLOAT -DSKIP_DECIMAL_FLOAT -c  -m64
--save-temps -o c_compat_main_tst.o
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/testsuite/gcc/gcc.dg-struct-layout-1/t028_main.c
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/xgcc
-B/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/  -w
-I/sw/src/fink.build/gcc44-4.3.999-20081115/gcc-4.4-20081115/gcc/testsuite/gcc.dg/compat
-mno-mmx -fno-common -DSKIP_DECIMAL_FLOAT -DSKIP_DECIMAL_FLOAT -c  -m64
--save-temps -o c_compat_x_tst.o
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/testsu
ite/gcc/gcc.dg-struct-layout-1//t028_x.c
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/xgcc
-B/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/  -w
-I/sw/src/fink.build/gcc44-4.3.999-20081115/gcc-4.4-20081115/gcc/testsuite/gcc.dg/compat
-mno-mmx -fno-common -DSKIP_DECIMAL_FLOAT -DSKIP_DECIMAL_FLOAT -c  -m64
--save-temps -o c_compat_y_tst.o
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/testsuite/gcc/gcc.dg-struct-layout-1//t028_y.c
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/xgcc
-B/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/
c_compat_main_tst.o c_compat_x_tst.o c_compat_y_tst.o 
-I/sw/src/fink.build/gcc44-4.3.999-20081115/gcc-4.4-20081115/gcc/testsuite/gcc.dg/compat
-mno-mmx -fno-common   -lm   -m64 -o tmpdir-gcc-dg-struct-layout-1-t028-01.exe


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[howarth at nitro dot med dot uc dot edu]

------- Comment #8 from howarth at nitro dot med dot uc dot edu  2008-11-16 15:55 -------
This failing testcase produces the following in gdb...

 gdb ./tmpdir-gcc-dg-struct-layout-1-t028-01.exe
GNU gdb 6.3.50-20050815 (Apple version gdb-962) (Sat Jul 26 08:14:40 UTC 2008)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-apple-darwin"...Reading symbols for shared
libraries ... done

(gdb) r
Starting program:
/sw/src/fink.build/gcc44-4.3.999-20081115/darwin_objdir/gcc/testsuite/gcc/tmpdir-gcc-dg-struct-layout-1-t028-01.exe 
warning: posix_spawn failed, trying execvp, error: 86
Reading symbols for shared libraries ++. done

Program received signal SIGABRT, Aborted.
0x00007fff83829ee6 in __kill ()
(gdb) bt
#0  0x00007fff83829ee6 in __kill ()
#1  0x00007fff8389af4d in abort ()
#2  0x0000000100000f6f in main ()
(gdb) 

Is there anything else I can provide to debug this?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] tmpdir-gcc.dg-struct-layout-1/t028 failure at -m64 on i686-apple-darwin9

[ubizjak at gmail dot com]

------- Comment #9 from ubizjak at gmail dot com  2008-11-16 20:28 -------
(In reply to comment #8)
> This failing testcase produces the following in gdb...

> #0  0x00007fff83829ee6 in __kill ()
> #1  0x00007fff8389af4d in abort ()
> #2  0x0000000100000f6f in main ()
> (gdb) 
> 
> Is there anything else I can provide to debug this?

Yes: compile all three testfiles with -g flag added, put a watchpoint on
"fails" variable (watch fails) and see where it triggers.

It looks to me that something is wrong with s2848 argument that is passed to
check2848 function. At calling site (in test2848 function), we have:

(gdb) print s2848
$10 = {a = 4027477739, b = -936922831153888968, c = 0x601720}

and in check2848 we receive:

(gdb) print arg0
$11 = {a = 4195077, b = 3221252723567493120, c = 0x7fffde0e11a0}

The structure is defined as:

     struct S2848
     {
       unsigned int a;
       _Complex int __attribute__ ((aligned (1))) b;
       struct
       {
       } __attribute__ ((packed, aligned)) c[1];
     };

Hm, looks like a real bug to me.

This also fails on linux, I'll try to create a testcase.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #10 from ubizjak at gmail dot com  2008-11-16 20:58 -------
Real bug with argument passing. Confirmed on x86_64-linux-gnu with the
testcase:

--cut here--
struct S2848
{
  unsigned int a;
  _Complex int b;
};

struct S2848 s2848;

void __attribute__((noinline))
check2848 (struct S2848 arg0)
{
  if (arg0.b != s2848.b)
    abort ();
}

int main()
{
  s2848.a = 4027477739U;
  s2848.b = (723419448 + -218144346 * __extension__ 1i);

  check2848 (s2848);

  return 0;
}
--cut here--

> gcc -O2 t.c
> ./a.out
Aborted


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl at gcc dot gnu dot org,
                   |                            |hubicka at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   GCC host triplet|i686-apple-darwin9          |
 GCC target triplet|i686-apple-darwin9          |x86_64
           Keywords|                            |ABI, wrong-code
      Known to fail|                            |4.3.0 4.4.0
   Last reconfirmed|0000-00-00 00:00:00         |2008-11-16 20:58:10
               date|                            |
            Summary|tmpdir-gcc.dg-struct-layout-|structures with _Complex
                   |1/t028 failure at -m64 on   |arguments are not passed
                   |i686-apple-darwin9          |correctly


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug testsuite/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #11 from ubizjak at gmail dot com  2008-11-16 21:09 -------
Also fails in return from function:

--cut here--
struct S2848
{
  unsigned int a;
  _Complex int b;
};

struct S2848 s2848;

struct S2848 __attribute__((noinline))
check2848 (struct S2848 arg0)
{
  s2848.a = 4027477739U;
  s2848.b = (723419448 + -218144346 * __extension__ 1i);

  return s2848;
}

int main()
{
  struct S2848 ret;

  ret = check2848 (s2848);

  if (ret.b != s2848.b)
    abort ();
  return 0;
}
--cut here--


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #12 from ubizjak at gmail dot com  2008-11-19 19:32 -------
Created an attachment (id=16723)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16723&action=view)
Da patch.

Jack, can you try attached patch?


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ubizjak at gmail dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #13 from ubizjak at gmail dot com  2008-11-19 21:17 -------
(In reply to comment #12)
> Created an attachment (id=16723)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16723&action=view) [edit]
> Da patch.
> 
> Jack, can you try attached patch?

Patch at http://gcc.gnu.org/ml/gcc-patches/2008-11/msg01010.html

It looks we still fail va_arg cases. But number of failures with the original
testcase drops from 10 to 4.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[howarth at nitro dot med dot uc dot edu]

------- Comment #14 from howarth at nitro dot med dot uc dot edu  2008-11-20 01:10 -------
The patch from Comment 13 when applied to gcc trunk (without a complete
bootstrap) eliminates the failures in gcc.dg-struct-layout-1 at -m64 while not
introducing any at -m32 on i686-apple-darwin9. I am doing a complete bootstrap
and make check against current gcc trunk.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[howarth at nitro dot med dot uc dot edu]

------- Comment #15 from howarth at nitro dot med dot uc dot edu  2008-11-20 12:55 -------
The patch in comment 13 appears to be sufficient to completely fix the problem
on i686-apple-darwin9.
The results for current gcc trunk with the patch...

http://gcc.gnu.org/ml/gcc-testresults/2008-11/msg01712.html

...compared to those without the patch...

http://gcc.gnu.org/ml/gcc-testresults/2008-11/msg01535.html

shows that...

FAIL: tmpdir-gcc.dg-struct-layout-1/t028 c_compat_x_tst.o-c_compat_y_tst.o
execute 

is eliminated at -m64 without any regressions in other tests.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #16 from ubizjak at gmail dot com  2008-11-20 19:50 -------
Problems from Comment #10 and Comment #11 are fixed by the patch from Comment
#13, but following test still fails, even with a patched compiler:

--cut here--
void abort (void);

struct S2848
{
  unsigned int a;
  _Complex int b;
  struct
  {
  } __attribute__ ((aligned)) c;
};

struct S2848 s2848;

int fails;

void  __attribute__((noinline))
check2848va (int z, ...)
{
  struct S2848 arg;
  __builtin_va_list ap;

  __builtin_va_start (ap, z);

  arg = __builtin_va_arg (ap, struct S2848);

  if (s2848.a != arg.a)
    ++fails;
  if (s2848.b != arg.b)
    ++fails;

  __builtin_va_end (ap);
}

int main (void)
{
  s2848.a = 4027477739U;
  s2848.b = (723419448 + -218144346 * __extension__ 1i);

  check2848va (1, s2848);

  if (fails)
    abort ();

  return 0;
}
--cut here--

> gcc -O2 t1.c

> ./a.out
Aborted

> gdb ./a.out
[...]
(gdb) watch fails
Hardware watchpoint 1: fails
(gdb) run
Starting program: /home/uros/test/compat/a.out 
Hardware watchpoint 1: fails

Old value = 0
New value = 1
0x000000000040051d in check2848va (z=1) at t1.c:29
29          ++fails;
Missing separate debuginfos, use: debuginfo-install glibc.x86_64
(gdb) p /x arg.b
$2 = 0x004005802b1e8138
(gdb) p /x s2848.b
$3 = 0xf2ff61a62b1e8138


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[uros at gcc dot gnu dot org]

------- Comment #17 from uros at gcc dot gnu dot org  2008-11-20 21:12 -------
Subject: Bug 38151

Author: uros
Date: Thu Nov 20 21:11:22 2008
New Revision: 142059

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=142059
Log:
        PR target/38151
        * config/i386/i386.c (classify_argument) [integer mode size <= 64bit]:
        Handle cases when integer argument crosses argument register boundary.

testsuite/ChangeLog:

        PR target/38151
        * gcc.target/i386/pr38151-1.c: New test.


Added:
    trunk/gcc/testsuite/gcc.target/i386/pr38151-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #18 from ubizjak at gmail dot com  2008-11-20 21:13 -------
va_arg problem from Comment #16 remains unfixed.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #19 from ubizjak at gmail dot com  2008-11-20 21:37 -------
Hm, rdx gets corrupted:

check2848va:
.LFB0:
        .cfi_startproc
        movq    %rsi, %rcx      # tmp73,
        leaq    8(%rsp), %rax   #,
(+)     movq    %rdx, -40(%rsp) #,
        shrq    $32, %rcx       #,
        cmpl    %esi, s2848(%rip)       # tmp73, s2848.a
>>>	movq	-80(%rsp), %rdx	#, tmp74
        movq    %rax, -112(%rsp)        #, <variable>.overflow_arg_area
        leaq    -56(%rsp), %rax #,
        movq    %rsi, -48(%rsp) #,
        movl    $8, -120(%rsp)  #, <variable>.gp_offset
        movq    %rsi, -88(%rsp) # tmp70,
        movq    %rax, -104(%rsp)        #, <variable>.reg_save_area
        movq    %rsi, -72(%rsp) # tmp73, arg
        movq    %rdx, -64(%rsp) # tmp74, arg
        je      .L4     #,
        addl    $1, fails(%rip) #, fails
.L4:
        cmpl    %ecx, s2848+4(%rip)     # arg$b$real, s2848.b
        setne   %cl     #, tmp79
(++)    cmpl    %edx, s2848+8(%rip)     # arg$b$imag, s2848.b
        setne   %al     #, tmp82
        orb     %al, %cl        # tmp82, tmp79
        je      .L6     #,
        addl    $1, fails(%rip) #, fails

rdx is saved at the point of (+), corrupted at ">>>" and this corrupted value
is used at (++). The insn at ">>>" just falls in the insn stream from the sky,
it is not present if "a" is changed to "unsigned long" in S2848 structure.

In case when "a" is changed to "unsigned long", testcase works OK. The testcase
also works when insn at ">>>" is removed.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[howarth at nitro dot med dot uc dot edu]

------- Comment #20 from howarth at nitro dot med dot uc dot edu  2008-11-21 00:05 -------
The test case in comment 16 passes on i686-apple-darwin9 when compiled with
-m32 but fails when compiled with -m64.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #21 from ubizjak at gmail dot com  2008-11-22 12:33 -------
This is a trace what happens in the testcase, from .expand dump:

(2) [frame + 8 ]        <- si
(3) [frame + 16]        <- dx
(4) r62                 <- di

(8) r63                 <- virtual-incoming-args + 0
(9) r64                 <- virtual-stack-vars - 64
(10) [r64]              <- 8                            ;; gp_offset
(11) r65                <- virtual-stack-vars - 64
(12) [r65 + 8 ]         <- virtual-incoming-args        ;; overflow_arg_area
(13) r66                <- virtual-stack-vars - 64
(14) [r66 + 16]         <- frame                        ;; reg_save_area
(15) r61                <- [virtual-stack-vars - 64]    ;; gp_offset
if (r61 > 39)
   goto label 27

(19) r67                <- virtual-stack-vars - 32
(20) r68                <- zext (r61)
(21) r69                <- [virtual-stack-vars - 48]    ;; reg_save_area
(22) r70                <- [r69 + r68]
(23) [r67]              <- r70
(24) r58                <- virtual-stack-vars - 32
goto label 32

label 27:
(29) r72                <- [virtual-stack-vars - 56]    ;; overflow_arg_area
(30) r71                <- r72 + 15
(31) r58                <- r71 & -16

label 32:
(34) r73                <- [r58]
(35) [virtual-stack-vars - 16] <- r73
(36) r74                <- [r58 + 8]
(37) [virtual-stack-vars - 8 ] <- r74
(38) r60                <- [virual-stack-vars - 12]     ;; arg$b$real
(39) r59                <- [virual-stack-vars - 8 ]     ;; arg$b$imag

So, around insn (22), gcc forgets to copy dx register to reg_save_area. r74 is
then read from uninitialized reg_save_area slot.

I'm looking at va-arg handling implementation in i386.c. But I'm not familiar
with this code, so a bit of help would be most welcome here.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|ubizjak at gmail dot com    |unassigned at gcc dot gnu
                   |                            |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #22 from ubizjak at gmail dot com  2008-11-22 17:07 -------
Aliasing problems, gcc shoots himself in the foot...

When container consists of registers in different modes (due to
X86_64_INTEGERSI_CLASS optimization):

(parallel:BLK [
        (expr_list:REG_DEP_TRUE (reg:DI 0 ax)
            (const_int 0 [0x0]))
        (expr_list:REG_DEP_TRUE (reg:SI 1 dx)
            (const_int 8 [0x8]))
    ])

then ix86_gimplify_va_arg happily creates code with invalid aliasing (from
_.gimple dump):

  addr.0 = &va_arg_tmp.3;
> addr.4 = (long unsigned int *) addr.0;
  int_addr.5 = (long unsigned int *) int_addr.1;
  D.1615 = *int_addr.5;
  *addr.4 = D.1615;
> addr.6 = (unsigned int *) addr.0;
  D.1617 = addr.6 + 8;

We access addr.0 as (long unsigned int *) and as (unsigned int *. Following
optimization passes are more than happy to remove the second access.

So to prove my point, testcase compiled with -fno-strict-aliasing works OK.

These problems also apply to FPmode parameters passing through SSE regs, so
following patch moves registers from register area to tmp area in generic mode
that fits argument passing registers best: DImode for integer and V4SFmode for
SSE registers. This avoids aliasing problems.

Index: i386.c
===================================================================
--- i386.c      (revision 142120)
+++ i386.c      (working copy)
@@ -6750,7 +6750,8 @@ ix86_gimplify_va_arg (tree valist, tree 
            {
              rtx slot = XVECEXP (container, 0, i);
              rtx reg = XEXP (slot, 0);
-             enum machine_mode mode = GET_MODE (reg);
+             enum machine_mode mode
+               = SSE_REGNO_P (REGNO (reg)) ? V4SFmode : DImode;
              tree piece_type = lang_hooks.types.type_for_mode (mode, 1);
              tree addr_type = build_pointer_type (piece_type);
              tree src_addr, src;


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ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ubizjak at gmail dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-11-16 20:58:10         |2008-11-22 17:07:30
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[howarth at nitro dot med dot uc dot edu]

------- Comment #23 from howarth at nitro dot med dot uc dot edu  2008-11-22 17:39 -------
Patch in Comment 22 eliminates the va-arg test case failure at -m64 on
i686-apple-darwin9.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[rguenth at gcc dot gnu dot org]

------- Comment #24 from rguenth at gcc dot gnu dot org  2008-11-22 18:20 -------
The va-arg code should probably use ref-all pointers all over the place
instead.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[ubizjak at gmail dot com]

------- Comment #25 from ubizjak at gmail dot com  2008-11-22 19:30 -------
Deassigning me, this is tree stuff.


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ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|ubizjak at gmail dot com    |unassigned at gcc dot gnu
                   |                            |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[rguenth at gcc dot gnu dot org]

------- Comment #26 from rguenth at gcc dot gnu dot org  2008-11-22 20:41 -------
Even with ref-all pointers we end up with

<bb 5>:
  # addr.0{0}_1 = PHI <&va_arg_tmp.3(3), addr.0{0}_22(4)>
  # ap_38 = PHI <ap_56(3), ap_57(4)>
  # va_arg_tmp.3_39 = PHI <va_arg_tmp.3_55(3), va_arg_tmp.3_50(4)>
  addr.8_25 = (struct S2848 * {ref-all}) addr.0{0}_1;
  # VUSE <fails_48, ap_38, SMT.26_53>
  # arg_59 = VDEF <arg_58(D)>
  arg = *addr.8_25;

where the last stmt misses a VUSE of va_arg_tmp.3.  This looks like a bug
in alias computation.

I have a fix for that parts.  The gimplify_va_arg still needs to use ref-all
pointers properly.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug target/38151] structures with _Complex arguments are not passed correctly

[rguenth at gcc dot gnu dot org]

------- Comment #27 from rguenth at gcc dot gnu dot org  2008-11-22 20:41 -------
I have patches.


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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-11-22 17:07:30         |2008-11-22 20:41:24
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug middle-end/38151] structures with _Complex arguments are not passed correctly

[rguenth at gcc dot gnu dot org]

------- Comment #28 from rguenth at gcc dot gnu dot org  2008-11-25 10:34 -------
Fixed.


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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151

[Bug middle-end/38151] structures with _Complex arguments are not passed correctly

[rguenth at gcc dot gnu dot org]

------- Comment #29 from rguenth at gcc dot gnu dot org  2008-11-25 10:35 -------
Subject: Bug 38151

Author: rguenth
Date: Tue Nov 25 10:34:11 2008
New Revision: 142189

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=142189
Log:
2008-11-25  Richard Guenther  <rguenther@suse.de>

        PR middle-end/38151
        PR middle-end/38236
        * tree-ssa-alias.c (struct alias_info): Remove written_vars.
        Remove dereferenced_ptrs_store and dereferenced_ptrs_load
        in favor of dereferenced_ptrs.
        (init_alias_info): Adjust.
        (delete_alias_info): Likewise.
        (compute_flow_insensitive_aliasing): Properly
        include all aliased variables.
        (update_alias_info_1): Use dereferenced_ptrs.
        (setup_pointers_and_addressables): Likewise.
        (get_smt_for): Honor ref-all pointers and pointers with known alias
        set properly.
        * config/i386/i386.c (ix86_gimplify_va_arg): Use ref-all pointers.

        * gcc.c-torture/execute/pr38151.c: New testcase.
        * gcc.c-torture/execute/pr38236.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr38151.c
    trunk/gcc/testsuite/gcc.c-torture/execute/pr38236.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-alias.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38151