Re: PATCH] PR 49580

[Richard Guenther <richard dot guenther at gmail dot com>]

On Tue, Jul 5, 2011 at 1:08 PM, Razya Ladelsky <RAZYA@il.ibm.com> wrote:
> Zdenek Dvorak <rakdver@kam.mff.cuni.cz> wrote on 05/07/2011 13:37:41:
>
>> From: Zdenek Dvorak <rakdver@kam.mff.cuni.cz>
>> To: Razya Ladelsky/Haifa/IBM@IBMIL
>> Cc: gcc-patches@gcc.gnu.org, Richard Guenther
> <richard.guenther@gmail.com>
>> Date: 05/07/2011 13:37
>> Subject: Re: PATCH] PR 49580
>>
>> Hi,
>>
>> > I moved the adjustment of the loop's iterations from
>> > gimple_duplicate_sese_tail
>> > to tree-parloops.c, right before the call to
> gimple_duplicate_sese_tail.
>> > I repeated the bootstrap, regression and spec runs - no new
> regressions.
>> >
>> > OK to commit?
>>
>> OK,
>>
>> Zdenek
>
> I also want to commit this testcase, which is a reduced case of the gcc
> benchmark.
> I apologize for not submitting it together with the patch.
> OK?

Ok.

Thanks,
Richard.

> Thanks,
> Razya
>
>
>
>
>>
>> > Index: gcc/tree-parloops.c
>> > ===================================================================
>> > --- gcc/tree-parloops.c ? (revision 174166)
>> > +++ gcc/tree-parloops.c ? (working copy)
>> > @@ -1464,6 +1464,8 @@ transform_to_exit_first_loop (struct loop *loop,
> h
>> > ? ?gimple phi, nphi, cond_stmt, stmt, cond_nit;
>> > ? ?gimple_stmt_iterator gsi;
>> > ? ?tree nit_1;
>> > + ?edge exit_1;
>> > + ?tree new_rhs;
>> >
>> > ? ?split_block_after_labels (loop->header);
>> > ? ?orig_header = single_succ (loop->header);
>> > @@ -1492,6 +1494,38 @@ transform_to_exit_first_loop (struct loop
> *loop, h
>> > ? ? ? control = t;
>> > ? ? }
>> > ? ? ?}
>> > +
>> > + /* Setting the condition towards peeling the last iteration:
>> > + ? ?If the block consisting of the exit condition has the latch as
>> > + ? ?successor, then the body of the loop is executed before
>> > + ? ?the exit condition is tested. ?In such case, moving the
>> > + ? ?condition to the entry, causes that the loop will iterate
>> > + ? ?one less iteration (which is the wanted outcome, since we
>> > + ? ?peel out the last iteration). ?If the body is executed after
>> > + ? ?the condition, moving the condition to the entry requires
>> > + ? ?decrementing one iteration. ?*/
>> > + ?exit_1 = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
>> > + ?if (exit_1->dest == loop->latch)
>> > + ? ?new_rhs = gimple_cond_rhs (cond_stmt);
>> > + ?else
>> > + ?{
>> > + ? ?new_rhs = fold_build2 (MINUS_EXPR, TREE_TYPE (gimple_cond_rhs
>> (cond_stmt)),
>> > + ? ? ? ? ? ?gimple_cond_rhs (cond_stmt),
>> > + ? ? ? ? ? ?build_int_cst (TREE_TYPE (gimple_cond_rhs (cond_stmt)),
> 1));
>> > + ? ?if (TREE_CODE (gimple_cond_rhs (cond_stmt)) == SSA_NAME)
>> > + ? ? ?{
>> > + ? ?basic_block preheader;
>> > + ? ? gimple_stmt_iterator gsi1;
>> > +
>> > + ? ? preheader = loop_preheader_edge(loop)->src;
>> > + ? ? ? gsi1 = gsi_after_labels (preheader);
>> > + ? new_rhs = force_gimple_operand_gsi (&gsi1, new_rhs, true,
>> > + ? ? ? ? ? ? ? ? ? NULL_TREE,false,GSI_CONTINUE_LINKING);
>> > + ? ? ?}
>> > + ?}
>> > + ?gimple_cond_set_rhs (cond_stmt, unshare_expr (new_rhs));
>> > + ?gimple_cond_set_lhs (cond_stmt, unshare_expr (gimple_cond_lhs
>> (cond_stmt)));
>> > +
>> > ? ?bbs = get_loop_body_in_dom_order (loop);
>> >
>> > ? ?for (n = 0; bbs[n] != loop->latch; n++)
>> > Index: gcc/tree-cfg.c
>> > ===================================================================
>> > --- gcc/tree-cfg.c ? (revision 174166)
>> > +++ gcc/tree-cfg.c ? (working copy)
>> > @@ -5397,12 +5397,10 @@ gimple_duplicate_sese_tail (edge entry
> ATTRIBUTE_U
>> > ? ?int total_freq = 0, exit_freq = 0;
>> > ? ?gcov_type total_count = 0, exit_count = 0;
>> > ? ?edge exits[2], nexits[2], e;
>> > - ?gimple_stmt_iterator gsi,gsi1;
>> > + ?gimple_stmt_iterator gsi;
>> > ? ?gimple cond_stmt;
>> > ? ?edge sorig, snew;
>> > ? ?basic_block exit_bb;
>> > - ?basic_block iters_bb;
>> > - ?tree new_rhs;
>> > ? ?gimple_stmt_iterator psi;
>> > ? ?gimple phi;
>> > ? ?tree def;
>> > @@ -5483,35 +5481,6 @@ gimple_duplicate_sese_tail (edge entry
> ATTRIBUTE_U
>> > ? ?gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
>> > ? ?cond_stmt = gimple_copy (cond_stmt);
>> >
>> > - /* If the block consisting of the exit condition has the latch as
>> > - ? ?successor, then the body of the loop is executed before
>> > - ? ?the exit condition is tested. ?In such case, moving the
>> > - ? ?condition to the entry, causes that the loop will iterate
>> > - ? ?one less iteration (which is the wanted outcome, since we
>> > - ? ?peel out the last iteration). ?If the body is executed after
>> > - ? ?the condition, moving the condition to the entry requires
>> > - ? ?decrementing one iteration. ?*/
>> > - ?if (exits[1]->dest == orig_loop->latch)
>> > - ? ?new_rhs = gimple_cond_rhs (cond_stmt);
>> > - ?else
>> > - ?{
>> > - ? ?new_rhs = fold_build2 (MINUS_EXPR, TREE_TYPE (gimple_cond_rhs
>> (cond_stmt)),
>> > - ? ? ? ? ? ?gimple_cond_rhs (cond_stmt),
>> > - ? ? ? ? ? ?build_int_cst (TREE_TYPE (gimple_cond_rhs (cond_stmt)),
> 1));
>> > -
>> > - ? ?if (TREE_CODE (gimple_cond_rhs (cond_stmt)) == SSA_NAME)
>> > - ? ? ?{
>> > - ? iters_bb = gimple_bb (SSA_NAME_DEF_STMT (gimple_cond_rhs
> (cond_stmt)));
>> > - ? for (gsi1 = gsi_start_bb (iters_bb); !gsi_end_p (gsi1);
>> gsi_next (&gsi1))
>> > - ? ? if (gsi_stmt (gsi1) == SSA_NAME_DEF_STMT (gimple_cond_rhs
>> (cond_stmt)))
>> > - ? ? ? break;
>> > -
>> > - ? new_rhs = force_gimple_operand_gsi (&gsi1, new_rhs, true,
>> > - ? ? ? ? ? ? ? ? ? NULL_TREE,false,GSI_CONTINUE_LINKING);
>> > - ? ? ?}
>> > - ?}
>> > - ?gimple_cond_set_rhs (cond_stmt, unshare_expr (new_rhs));
>> > - ?gimple_cond_set_lhs (cond_stmt, unshare_expr (gimple_cond_lhs
>> (cond_stmt)));
>> > ? ?gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
>> >
>> > ? ?sorig = single_succ_edge (switch_bb);
>>
>> >
>> > 07-05-2011 ?Razya Ladelsky ?<razya@il.ibm.com>
>> >
>> > ? ?* tree-cfg.c (gimple_duplicate_sese_tail): Remove handling of
>> > ? ?the loop's number of iterations.
>> > ? ? ? ? * tree-parloops.c (transform_to_exit_first_loop): Add the
>> > ? ?handling of the loop's number of iterations before the call
>> > ? ?to gimple_duplicate_sese_tail.
>> > ? ? ? ? Insert the stmt caclculating the new rhs of the loop's
>> > ? ?condition stmt to the preheader instead of iters_bb.
>>
>