[Bug debug/43329] New: Early inlining causes suboptimal debug info

[Bug debug/43329] New: Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

The following testcase doesn't contain DW_AT_const_value for arrg3 nor min when
early inlining is used, while when normal inlining is performed all is fine.
-g -O2 --param early-inlining-insns=32 (doesn't work) vs.
-g -O2 --param early-inlining-insns=32 -fno-early-inlining
Sorry for the extra parameter, but the testcase was reported against 4.4-RH
which does 4.4-ish inlining decisions, so it needs some tweaks to get the same
effect in 4.5.
For arrg3, there are DEBUG stmts (and even var-tracking produces locations for
it), but dwarf2out ignores them, as the var has been non-localized (var_ann has
been NULL).  For min argument, a DEBUG stmt only appears when not using early
inlining.


-- 
           Summary: Early inlining causes suboptimal debug info
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: wrong-debug
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
GCC target triplet: x86_64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2010-03-10 23:29 -------
Created an attachment (id=20078)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20078&action=view)
rh572260.ii

Testcase.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #2 from jakub at gcc dot gnu dot org  2010-03-11 12:53 -------
The problem is that with early inlining, method (&inst, 24) call is inlined
into
call function, then at the end of einline during arrg3 and min vars in call are
removed as unused locals by remove_unused_locals (the inline asm uses 24
directly, so arrg3 is only referenced in DEBUG stmts, not sure why min didn't
have any DEBUG stmts even generated).  Then when in the normal inliner call is
inlined into main, both arrg3 and min are non-localized because their var_ann
is NULL.  And for non-localized vars dwarf2out isn't able to find the
dwarf2out_var_location tracked values.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2010-03-11 13:02 -------
Wonder why we do
548    VEC_safe_push (tree, gc, *nonlocalized_list, origin_var);
instead of
548    VEC_safe_push (tree, gc, *nonlocalized_list, old_var);
The latter perhaps would need some adjustments in dwarf2out.c, but would allow
it to find the location.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2010-03-11 14:46 -------
Created an attachment (id=20081)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20081&action=view)
gcc45-pr43329.patch

This patch worked on this testcase.  Note that the missing min (and this) DEBUG
stmts are caused by remove_forwarder_block nuking it.  Looking into that...


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #5 from jakub at gcc dot gnu dot org  2010-03-11 16:08 -------
Created an attachment (id=20084)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20084&action=view)
gcc45-pr43329.patch

Updated patch that also fixes remove_forwarder_block and adds a testcase.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #20081|0                           |1
        is obsolete|                            |
         AssignedTo|unassigned at gcc dot gnu   |jakub at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #6 from jakub at gcc dot gnu dot org  2010-03-12 13:04 -------
Subject: Bug 43329

Author: jakub
Date: Fri Mar 12 13:04:37 2010
New Revision: 157402

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=157402
Log:
        PR debug/43329
        * tree-inline.c (remap_decls): Put old_var rather than origin_var
        into *nonlocalized_list vector.
        * dwarf2out.c (gen_formal_parameter_die): Call decl_ultimate_origin
        even if origin is non-NULL.
        (gen_variable_die): Likewise.
        (process_scope_var): Don't change origin.
        (gen_decl_die): Likewise.
        * tree-cfgcleanup.c (remove_forwarder_block): Check single_pred_p
        before adding new edges instead of after it, fix moving over
        debug stmts.

        * gcc.dg/guality/pr43329-1.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/guality/pr43329-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dwarf2out.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-cfgcleanup.c
    trunk/gcc/tree-inline.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329

[Bug debug/43329] Early inlining causes suboptimal debug info

[jakub at gcc dot gnu dot org]

------- Comment #7 from jakub at gcc dot gnu dot org  2010-03-12 23:06 -------
Fixed.


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jakub at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43329