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re PR tree-optimization/35805 ([ira] error in start_allocno_priorities, at ira-color.c:1806)

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2009-01-02  Kenneth Zadeck <zadeck@naturalbridge.com>

	PR rtl-optimization/35805
	* df-problems.c (df_lr_finalize): Add recursive call to resolve lr
	problem if fast dce is able to remove any instructions.
	* dce.c (dce_process_block): Fix dump message.

From-SVN: r143027
This commit is contained in:
Kenneth Zadeck 2009-01-03 00:31:39 +00:00 • committed by Kenneth Zadeck
parent 0ede37fed4
commit fafe34f91a
3 changed files with 29 additions and 13 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2009-01-02 Kenneth Zadeck <zadeck@naturalbridge.com>
PR rtl-optimization/35805
* df-problems.c (df_lr_finalize): Add recursive call to resolve lr
problem if fast dce is able to remove any instructions.
* dce.c (dce_process_block): Fix dump message.
2009-01-02 Mark Mitchell <mark@codesourcery.com>
PR 33649

2
gcc/dce.c
View file

@ -601,7 +601,7 @@ dce_process_block (basic_block bb, bool redo_out, bitmap au)
if (dump_file)
{
fprintf (dump_file, "processing block %d live out = ", bb->index);
fprintf (dump_file, "processing block %d lr out = ", bb->index);
df_print_regset (dump_file, DF_LR_OUT (bb));
}

33
gcc/df-problems.c
View file

@ -1001,25 +1001,34 @@ df_lr_transfer_function (int bb_index)
/* Run the fast dce as a side effect of building LR. */
static void
df_lr_finalize (bitmap all_blocks ATTRIBUTE_UNUSED)
df_lr_finalize (bitmap all_blocks)
{
df_lr->solutions_dirty = false;
if (df->changeable_flags & DF_LR_RUN_DCE)
{
run_fast_df_dce ();
if (df_lr->problem_data && df_lr->solutions_dirty)
/* If dce deletes some instructions, we need to recompute the lr
solution before proceeding further. The problem is that fast
dce is a pessimestic dataflow algorithm. In the case where
it deletes a statement S inside of a loop, the uses inside of
S may not be deleted from the dataflow solution because they
were carried around the loop. While it is conservatively
correct to leave these extra bits, the standards of df
require that we maintain the best possible (least fixed
point) solution. The only way to do that is to redo the
iteration from the beginning. See PR35805 for an
example. */
if (df_lr->solutions_dirty)
{
/* If we are here, then it is because we are both verifying
the solution and the dce changed the function. In that case
the verification info built will be wrong. So we leave the
dirty flag true so that the verifier will skip the checking
part and just clean up.*/
df_lr->solutions_dirty = true;
df_clear_flags (DF_LR_RUN_DCE);
df_lr_alloc (all_blocks);
df_lr_local_compute (all_blocks);
df_worklist_dataflow (df_lr, all_blocks, df->postorder, df->n_blocks);
df_lr_finalize (all_blocks);
df_set_flags (DF_LR_RUN_DCE);
}
else
df_lr->solutions_dirty = false;
}
else
df_lr->solutions_dirty = false;
}