[Bug tree-optimization/33619] New: [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[Bug tree-optimization/33619] New: [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[pinskia at gcc dot gnu dot org]

Related to PR 29877.

Take the following PPC64-linux code (ignore the fact the inline-asm should be
improved a lot via use of clobbers).
static inline int sys_ppu_thread_set_priority(sys_ppu_thread_t thread_id,int
prio)
{
 register uint64_t p1 __asm__ ("3") = thread_id; 
register uint64_t p2 __asm__ ("4") = prio; 
register uint64_t p3 __asm__ ("5"); register uint64_t p4 __asm__ ("6");
register uint64_t p5 __asm__ ("7"); register uint64_t p6 __asm__ ("8");
register uint64_t p7 __asm__ ("9"); 
register uint64_t p8 __asm__ ("10"); 
register uint64_t n __asm__ ("11") = 47;
 __asm__ volatile ("sc" : "=r" (p1), "=r" (p2), "=r" (p3), "=r" (p4), "=r"
(p5), "=r" (p6), "=r" (p7), "=r" (p8), "=r" (n) : "r" (p1), "r" (p2), "r" (p3),
"r" (p4), "r" (p5), "r" (p6), "r" (p7), "r" (p8), "r" (n) : "0", "12", "lr",
"ctr", "xer", "cr0", "cr1", "cr5", "cr6", "cr7", "memory");
 return (int)(p1);
}
int32_t P(int32_t priority){return 0;}
struct Thread {
 sys_ppu_thread_t tid;
 Thread();
 void setPriority(int32_t p);
};
void Thread::setPriority(int32_t p)
{
 sys_ppu_thread_t a = tid;
 sys_ppu_thread_set_priority(a, P(p));
}


---------------- CUT --------------------
Right now we get in .optimized:
  p1 = this->tid;
  p2 = (uint64_t) P (p);

Which is wrong as the assignment of p1 happens before the call to P so we
clobber it during the setup of the call.


-- 
           Summary: [4.1/4.2/4.3 Regression] TER breaks some inline-asm code
                    (again)
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: blocker
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
GCC target triplet: powerpc64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.2.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2007-10-02 13:38 -------
Simplified testcase which also fails on x86_64-linux:

/* PR tree-optimization/33619 */
/* { dg-do run } */
/* { dg-options "-O2" } */

#ifdef __powerpc__
# define REG1 "3"
# define REG2 "4"
#elif defined __x86_64__
# define REG1 "rdi"
# define REG2 "rsi"
#endif

static inline void
bar (unsigned long x, int y)
{
  register unsigned long p1 __asm__ (REG1) = x;
  register unsigned long p2 __asm__ (REG2) = y;
  __asm__ volatile ("" : "=r" (p1), "=r" (p2) : "0" (p1), "1" (p2) : "memory");
  if (p1 != 0xdeadUL || p2 != 0xbefUL)
    __builtin_abort ();
}

__attribute__((const, noinline)) int
baz (int x)
{
  return x;
}

__attribute__((noinline)) void
foo (unsigned long *x, int y)
{
  unsigned long a = *x;
  bar (a, baz (y));
}

int
main (void)
{
  unsigned long a = 0xdeadUL;
  foo (&a, 0xbefUL);
  return 0;
}

In the presence of DECL_HARD_REGISTER vars making any kind of calls, even when
they are const or pure, replaceable is IMHO wrong.  Does it buy us anything to
make any calls replaceable (i.e. what would we lose by simply
if (get_call_expr_in (stmt))
  return false;
in is_replaceable_p)?  If yes, we either need to disallow them if the current
BB ever sets or uses any DECL_HARD_REGISTER vars, or need to do analysis
if the replacement in rewrite_trees crosses any such sets or uses.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2007-10-02 23:30 -------
Note disabling the replacement for pure/const functions does in fact make this
testcase work.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2007-10-04 19:05 -------
> Does it buy us anything to make any calls replaceable (i.e. what
> would we lose by simply
> if (get_call_expr_in (stmt))
>  return false;
> in is_replaceable_p)?

Before 4.2 when loop.c existed, we would lose the ablity for __builtin_expect
working correctly.  In 4.2 and above, we "fold" __builtin_expect early on the
tree level and place the info on the edges instead.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2007-10-05 10:58 -------
If __builtin_expect is the only problem, then we could certainly allow
__builtin_expect to be replaceable (perhaps add a few other builtin calls
that never result in any actual calls, like __builtin_object_size).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[pinskia at gmail dot com]

------- Comment #5 from pinskia at gmail dot com  2007-10-05 17:05 -------
Subject: Re:  [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

On 5 Oct 2007 10:58:10 -0000, jakub at gcc dot gnu dot org
<gcc-bugzilla@gcc.gnu.org> wrote:
>
>
> ------- Comment #4 from jakub at gcc dot gnu dot org  2007-10-05 10:58 -------
> If __builtin_expect is the only problem, then we could certainly allow
> __builtin_expect to be replaceable (perhaps add a few other builtin calls
> that never result in any actual calls, like __builtin_object_size).

well those should be foldded before exand now so i am not worried about them.

--Pinski


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[mmitchel at gcc dot gnu dot org]

------- Comment #6 from mmitchel at gcc dot gnu dot org  2007-10-09 19:20 -------
Change target milestone to 4.2.3, as 4.2.2 has been released.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.2                       |4.2.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jakub at gcc dot gnu dot org
                   |dot org                     |
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2007-
                   |                            |10/msg00688.html
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-10-12 08:35:03
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2/4.3 Regression] TER breaks some inline-asm code (again)

[jakub at gcc dot gnu dot org]

------- Comment #7 from jakub at gcc dot gnu dot org  2007-10-15 15:14 -------
Subject: Bug 33619

Author: jakub
Date: Mon Oct 15 15:14:46 2007
New Revision: 129350

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=129350
Log:
        PR tree-optimization/33619
        * tree-ssa-ter.c (is_replaceable_p): Return false for all
        calls.

        * gcc.dg/pr33619.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr33619.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-ter.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2 Regression] TER breaks some inline-asm code (again)

[jakub at gcc dot gnu dot org]

------- Comment #8 from jakub at gcc dot gnu dot org  2007-10-15 18:49 -------
Fixed so far on the trunk.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.1/4.2/4.3 Regression] TER|[4.1/4.2 Regression] TER
                   |breaks some inline-asm code |breaks some inline-asm code
                   |(again)                     |(again)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2 Regression] TER breaks some inline-asm code (again)

[jsm28 at gcc dot gnu dot org]

------- Comment #9 from jsm28 at gcc dot gnu dot org  2008-02-01 16:54 -------
4.2.3 is being released now, changing milestones of open bugs to 4.2.4.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.3                       |4.2.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.1/4.2 Regression] TER breaks some inline-asm code (again)

[jsm28 at gcc dot gnu dot org]

------- Comment #10 from jsm28 at gcc dot gnu dot org  2008-05-19 20:23 -------
4.2.4 is being released, changing milestones to 4.2.5.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.4                       |4.2.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.2 Regression] TER breaks some inline-asm code (again)

[jsm28 at gcc dot gnu dot org]

------- Comment #11 from jsm28 at gcc dot gnu dot org  2008-07-04 22:51 -------
Closing 4.1 branch.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.1/4.2 Regression] TER    |[4.2 Regression] TER breaks
                   |breaks some inline-asm code |some inline-asm code (again)
                   |(again)                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619

[Bug tree-optimization/33619] [4.2 Regression] TER breaks some inline-asm code (again)

[jsm28 at gcc dot gnu dot org]

------- Comment #12 from jsm28 at gcc dot gnu dot org  2009-03-30 22:29 -------
Closing 4.2 branch, fixed in 4.3.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to fail|                            |4.2.5
      Known to work|                            |4.3.0
         Resolution|                            |FIXED
   Target Milestone|4.2.5                       |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33619