[Bug debug/67043] New: [6 Regression] -fcompare-debug failure with -O3

[Bug debug/67043] New: [6 Regression] -fcompare-debug failure with -O3

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

            Bug ID: 67043
           Summary: [6 Regression] -fcompare-debug failure with -O3
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
  Target Milestone: ---

% cat test.i
extern void rt_mutex_owner(void);
extern void rt_mutex_deadlock_account_lock(int);
extern void signal_pending(void);
__typeof__(int *) a;
int b;
int
try_to_take_rt_mutex(int p1) {
  rt_mutex_owner();
  if (b)
    return 0;
  rt_mutex_deadlock_account_lock(p1);
  return 1;
}
void
__rt_mutex_slowlock(int p1) {
  int c;
  for (;;) {
    c = ({
      asm("" : "=r"(a));
      a;
    });
    if (try_to_take_rt_mutex(c))
      break;
    if (__builtin_expect(p1 == 0, 0))
      signal_pending();
  }
}

 % gcc --save-temps -fcompare-debug -O3 -w -c test.i
gcc: error: test.i: -fcompare-debug failure

 % diff -u test.gkd test.gk.gkd
--- test.gkd    2015-07-28 12:25:03.890035508 +0200
+++ test.gk.gkd 2015-07-28 12:25:03.926034824 +0200
@@ -220,10 +220,10 @@
 (code_label # 0 0 5 9 "" [2 uses])
 (note # 0 0 [bb 5] NOTE_INSN_BASIC_BLOCK)
 (insn:TI # 0 0 5 (set (mem/f/c:DI (symbol_ref:DI ("a") [flags 0x2]  <var_decl
# a>) [ a+0 S8 A64])
-        (reg:DI 3 bx [94])) test.i:19# {*movdi_internal}
+        (reg:DI 3 bx [95])) test.i:19# {*movdi_internal}
      (nil))
 (insn # 0 0 5 (set (reg/f:DI 6 bp [orig:91 D.xxxx ] [91])
-        (reg:DI 3 bx [94])) test.i:20# {*movdi_internal}
+        (reg:DI 3 bx [95])) test.i:20# {*movdi_internal}
      (nil))
 (call_insn:TI # 0 0 5 (call (mem:QI (symbol_ref:DI ("rt_mutex_owner") [flags
0x41]  <function_decl # rt_mutex_owner>) [ rt_mutex_owner S1 A8])
         (const_int 0 [0])) test.i:8# {*call}

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |6.0

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Does the testcase you reduced this from end up generating different code?

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> Does the testcase you reduced this from end up generating different code?

No. (It was reduced from the Linux kernel: kernel/locking/rtmutex.c).

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

--- Comment #3 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Created attachment 36081
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36081&action=edit
unreduced testcase

Unreduced testcase is attached.

 % gcc --save-temps -c -fno-partial-inlining -O3 -fcompare-debug rtmutex.i
gcc: error: rtmutex.i: -fcompare-debug failure

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-07-28
                 CC|                            |thopre01 at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Started with r223113.

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

--- Comment #5 from Thomas Preud'homme <thopre01 at gcc dot gnu.org> ---
Mmmh, that seems to be because luid are not up-to-date. Running
df_recompute_luids before can_move_invariant_reg makes the issue go away.

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

Thomas Preud'homme <thopre01 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |thopre01 at gcc dot gnu.org

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[thopre01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

--- Comment #6 from Thomas Preud'homme <thopre01 at gcc dot gnu.org> ---
Author: thopre01
Date: Tue Aug  4 02:11:58 2015
New Revision: 226540

URL: https://gcc.gnu.org/viewcvs?rev=226540&root=gcc&view=rev
Log:
2015-08-04  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    PR tree-optimization/67043
    * loop-invariant.c (move_invariant_reg): Recompute luids in loop
    preheader after hoisting invariant in it.
    (find_defs): Force recomputation of all luids.

    gcc/testsuite/
    PR tree-optimization/67043
    * gcc.dg/pr67043.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr67043.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/loop-invariant.c
    trunk/gcc/testsuite/ChangeLog

[Bug debug/67043] [6 Regression] -fcompare-debug failure with -O3

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67043

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

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

--- Comment #7 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Fixed. Thanks.