[Bug c/15968] New: [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[Bug c/15968] New: [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[danglin at gcc dot gnu dot org]

FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O0 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O1 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O2 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O3 -fomit-frame-pointer 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O3 -fomit-frame-pointer -
funroll-loops 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O3 -fomit-frame-pointer -
funroll-all-loops -finline-functions 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -O3 -g 
FAIL: gcc.c-torture/execute/va-arg-22.c execution,  -Os

See < http://gcc.gnu.org/ml/gcc-testresults/2004-06/msg00467.html>.

I'm not sure whether this was intentional or not but va-arg-22.c passes
an empty struct D(0).  If I change this typedef from

#define D(N) typedef struct { char x[N]; } A##N;

to

#define D(N) typedef struct { char x[N+1]; } A##N;

the test passes.

We pass empty structs by reference.  I think va_arg

#define D(N)                                    \
  a##N = va_arg (ap, typeof (a##N));            \
  for (i = 0; i < N; i++)                       \
    bar (N, a##N.x[i]);
D(0) D(1) D(2) D(3) D(4) D(5) D(6) D(7)
...

in foo is broken for a0, when a0 is an empty struct.

-- 
           Summary: [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails
                    on hppa64-hp-hpux11.11
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danglin at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org,jakub at redhat dot
                    com,jason at redhat dot com
 GCC build triplet: hppa64-hp-hpux11.11
  GCC host triplet: hppa64-hp-hpux11.11
GCC target triplet: hppa64-hp-hpux11.11


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15968

[Bug target/15968] [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-13 08:51 -------
No this is testing if you can pass an empty stuct too so that is deliberate.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |target
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15968

[Bug target/15968] [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[jason at gcc dot gnu dot org]

------- Additional Comments From jason at gcc dot gnu dot org  2004-06-14 16:00 -------
Want to take a crack at implementing TARGET_GIMPLIFY_VA_ARG_EXPR, to see if that
fixes it?

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15968

[Bug target/15968] [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[dave at hiauly1 dot hia dot nrc dot ca]

------- Additional Comments From dave at hiauly1 dot hia dot nrc dot ca  2004-06-15 00:16 -------
Subject: Re:  [3.5 Regression] gcc.c-torture/execute/va-arg-

> Want to take a crack at implementing TARGET_GIMPLIFY_VA_ARG_EXPR, to see if
> that
> fixes it?

I'm working on a small contract at the moment but after it completes
this is definitely something that should be looked at, even if it's
only for the learning experience.

I think the current problem is with va_start.  I see the following
error message with the testscase and a simplified version xxx.c:

# ../xgcc -B../ -O1 -s -o xyz.s xxx.c
xxx.c: In function `foo':
xxx.c:37: warning: second parameter of `va_start' not last named argument

xxx.c contains just D(0) and D(1) from the original test.  Looking at
the assembler output, I see that we are loading the high order byte
from the argument passed for D(0) instead of that for D(1).

I still don't know why this is happening.  The same code works in 3.3
and 3.4, and for some reason nearly identical code seems to work on the
32-bit port.  In both cases, empty structs are passed by reference.

Dave


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15968

[Bug target/15968] [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-15 00:33 -------
Actually I know what is happeing here is that the variable is being marked as addressable so it is being 
gimplified wrong for va_start, see PR 15885.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-06-15 00:33:01
               date|                            |
   Target Milestone|---                         |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15968

[Bug target/15968] [3.5 Regression] gcc.c-torture/execute/va-arg-22.c fails on hppa64-hp-hpux11.11

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-08-03 22:17 -------
I see that this passes now: <http://gcc.gnu.org/ml/gcc-testresults/2004-07/msg01349.html>.
Closing as fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15968