On Mon, 11 Dec 2017, Jakub Jelinek wrote:
> Hi!
>
> Unlike LOOP_VECTORIZED ifns, LOOP_DIST_ALIAS is added by the ldist pass
> and needs to be maintained until the vectorizer, and parloops in between
> that. Earlier I've added code to update or drop orig_loop_num during
> move_sese_region_to_fn, but that is not sufficient. If we move
> the whole pair of loops with the associated LOOP_DIST_ALIAS call into
> the outlined loopfn, we need to update the first argument, as orig_loop_num
> is likely changing. If the whole triplet (two loops with orig_loop_num
> and LOOP_DIST_ALIAS with the same first argument) stays in parent function,
> we don't need to adjust it. In all other cases, this patch folds the
> LOOP_DIST_ALIAS ifn to the second argument, like the vectorizer does if
> it fails to vectorize it.
>
> Bootstrapped/regtested on x86_64-linux, i686-linux, powerpc64le-linux,
> bootstrapped on powerpc64-linux, regtest there pending. Ok for trunk?
Ok.
Thanks,
Richard.
> 2017-12-11 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/83359
> * tree-cfg.h (fold_loop_internal_call): Declare.
> * tree-vectorizer.c (fold_loop_internal_call): Moved to ...
> * tree-cfg.c (fold_loop_internal_call): ... here. No longer static.
> (find_loop_dist_alias): New function.
> (move_sese_region_to_fn): If any dloop->orig_loop_num value is
> updated, also adjust any corresponding LOOP_DIST_ALIAS internal
> calls.
>
> * gcc.dg/graphite/pr83359.c: New test.
>
> --- gcc/tree-cfg.h.jj 2017-09-05 23:28:14.000000000 +0200
> +++ gcc/tree-cfg.h 2017-12-11 12:35:24.284777550 +0100
> @@ -77,6 +77,7 @@ extern void gather_blocks_in_sese_region
> vec<basic_block> *bbs_p);
> extern void verify_sese (basic_block, basic_block, vec<basic_block> *);
> extern bool gather_ssa_name_hash_map_from (tree const &, tree const &, void
> *);
> +extern void fold_loop_internal_call (gimple *, tree);
> extern basic_block move_sese_region_to_fn (struct function *, basic_block,
> basic_block, tree);
> extern void dump_function_to_file (tree, FILE *, dump_flags_t);
> --- gcc/tree-vectorizer.c.jj 2017-09-01 09:26:37.000000000 +0200
> +++ gcc/tree-vectorizer.c 2017-12-11 12:33:41.436055580 +0100
> @@ -464,27 +464,6 @@ vect_loop_vectorized_call (struct loop *
> return NULL;
> }
>
> -/* Fold loop internal call G like IFN_LOOP_VECTORIZED/IFN_LOOP_DIST_ALIAS
> - to VALUE and update any immediate uses of it's LHS. */
> -
> -static void
> -fold_loop_internal_call (gimple *g, tree value)
> -{
> - tree lhs = gimple_call_lhs (g);
> - use_operand_p use_p;
> - imm_use_iterator iter;
> - gimple *use_stmt;
> - gimple_stmt_iterator gsi = gsi_for_stmt (g);
> -
> - update_call_from_tree (&gsi, value);
> - FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
> - {
> - FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
> - SET_USE (use_p, value);
> - update_stmt (use_stmt);
> - }
> -}
> -
> /* If LOOP has been versioned during loop distribution, return the gurading
> internal call. */
>
> --- gcc/tree-cfg.c.jj 2017-12-07 18:05:30.000000000 +0100
> +++ gcc/tree-cfg.c 2017-12-11 12:34:55.054140750 +0100
> @@ -7337,6 +7337,47 @@ gather_ssa_name_hash_map_from (tree cons
> return true;
> }
>
> +/* Return LOOP_DIST_ALIAS call if present in BB. */
> +
> +static gimple *
> +find_loop_dist_alias (basic_block bb)
> +{
> + gimple *g = last_stmt (bb);
> + if (g == NULL || gimple_code (g) != GIMPLE_COND)
> + return NULL;
> +
> + gimple_stmt_iterator gsi = gsi_for_stmt (g);
> + gsi_prev (&gsi);
> + if (gsi_end_p (gsi))
> + return NULL;
> +
> + g = gsi_stmt (gsi);
> + if (gimple_call_internal_p (g, IFN_LOOP_DIST_ALIAS))
> + return g;
> + return NULL;
> +}
> +
> +/* Fold loop internal call G like IFN_LOOP_VECTORIZED/IFN_LOOP_DIST_ALIAS
> + to VALUE and update any immediate uses of it's LHS. */
> +
> +void
> +fold_loop_internal_call (gimple *g, tree value)
> +{
> + tree lhs = gimple_call_lhs (g);
> + use_operand_p use_p;
> + imm_use_iterator iter;
> + gimple *use_stmt;
> + gimple_stmt_iterator gsi = gsi_for_stmt (g);
> +
> + update_call_from_tree (&gsi, value);
> + FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
> + {
> + FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
> + SET_USE (use_p, value);
> + update_stmt (use_stmt);
> + }
> +}
> +
> /* Move a single-entry, single-exit region delimited by ENTRY_BB and
> EXIT_BB to function DEST_CFUN. The whole region is replaced by a
> single basic block in the original CFG and the new basic block is
> @@ -7510,7 +7551,6 @@ move_sese_region_to_fn (struct function
> }
> }
>
> -
> /* Adjust the number of blocks in the tree root of the outlined part. */
> get_loop (dest_cfun, 0)->num_nodes = bbs.length () + 2;
>
> @@ -7521,19 +7561,77 @@ move_sese_region_to_fn (struct function
> /* Fix up orig_loop_num. If the block referenced in it has been moved
> to dest_cfun, update orig_loop_num field, otherwise clear it. */
> struct loop *dloop;
> + signed char *moved_orig_loop_num = NULL;
> FOR_EACH_LOOP_FN (dest_cfun, dloop, 0)
> if (dloop->orig_loop_num)
> {
> + if (moved_orig_loop_num == NULL)
> + moved_orig_loop_num
> + = XCNEWVEC (signed char, vec_safe_length (larray));
> if ((*larray)[dloop->orig_loop_num] != NULL
> && get_loop (saved_cfun, dloop->orig_loop_num) == NULL)
> - dloop->orig_loop_num = (*larray)[dloop->orig_loop_num]->num;
> + {
> + if (moved_orig_loop_num[dloop->orig_loop_num] >= 0
> + && moved_orig_loop_num[dloop->orig_loop_num] < 2)
> + moved_orig_loop_num[dloop->orig_loop_num]++;
> + dloop->orig_loop_num = (*larray)[dloop->orig_loop_num]->num;
> + }
> else
> - dloop->orig_loop_num = 0;
> + {
> + moved_orig_loop_num[dloop->orig_loop_num] = -1;
> + dloop->orig_loop_num = 0;
> + }
> }
> - ggc_free (larray);
> -
> pop_cfun ();
>
> + if (moved_orig_loop_num)
> + {
> + FOR_EACH_VEC_ELT (bbs, i, bb)
> + {
> + gimple *g = find_loop_dist_alias (bb);
> + if (g == NULL)
> + continue;
> +
> + int orig_loop_num = tree_to_shwi (gimple_call_arg (g, 0));
> + gcc_assert (orig_loop_num
> + && (unsigned) orig_loop_num < vec_safe_length (larray));
> + if (moved_orig_loop_num[orig_loop_num] == 2)
> + {
> + /* If we have moved both loops with this orig_loop_num into
> + dest_cfun and the LOOP_DIST_ALIAS call is being moved there
> + too, update the first argument. */
> + gcc_assert ((*larray)[dloop->orig_loop_num] != NULL
> + && (get_loop (saved_cfun, dloop->orig_loop_num)
> + == NULL));
> + tree t = build_int_cst (integer_type_node,
> + (*larray)[dloop->orig_loop_num]->num);
> + gimple_call_set_arg (g, 0, t);
> + update_stmt (g);
> + /* Make sure the following loop will not update it. */
> + moved_orig_loop_num[orig_loop_num] = 0;
> + }
> + else
> + /* Otherwise at least one of the loops stayed in saved_cfun.
> + Remove the LOOP_DIST_ALIAS call. */
> + fold_loop_internal_call (g, gimple_call_arg (g, 1));
> + }
> + FOR_EACH_BB_FN (bb, saved_cfun)
> + {
> + gimple *g = find_loop_dist_alias (bb);
> + if (g == NULL)
> + continue;
> + int orig_loop_num = tree_to_shwi (gimple_call_arg (g, 0));
> + gcc_assert (orig_loop_num
> + && (unsigned) orig_loop_num < vec_safe_length (larray));
> + if (moved_orig_loop_num[orig_loop_num])
> + /* LOOP_DIST_ALIAS call remained in saved_cfun, if at least one
> + of the corresponding loops was moved, remove it. */
> + fold_loop_internal_call (g, gimple_call_arg (g, 1));
> + }
> + XDELETEVEC (moved_orig_loop_num);
> + }
> + ggc_free (larray);
> +
> /* Move blocks from BBS into DEST_CFUN. */
> gcc_assert (bbs.length () >= 2);
> after = dest_cfun->cfg->x_entry_block_ptr;
> --- gcc/testsuite/gcc.dg/graphite/pr83359.c.jj 2017-12-11
> 11:43:10.433737382 +0100
> +++ gcc/testsuite/gcc.dg/graphite/pr83359.c 2017-12-11 11:43:01.000000000
> +0100
> @@ -0,0 +1,40 @@
> +/* PR tree-optimization/83359 */
> +/* { dg-do compile { target pthread } } */
> +/* { dg-options "-O3 -floop-parallelize-all -ftree-parallelize-loops=2" } */
> +
> +int a, b, c;
> +
> +void
> +foo (int x, int y)
> +{
> + int *d = &a;
> + int *e = &x;
> +
> + for (a = 0; a < 1; ++a)
> + d = &x;
> +
> + while (b < 10)
> + {
> + for (b = 0; b < 1; ++b)
> + if (x == 0)
> + while (x < 1)
> + ++x;
> + else
> + while (x < 1)
> + {
> + d = &y;
> + ++x;
> + }
> + ++b;
> + }
> +
> + for (;;)
> + for (c = 0; c < 2; ++c)
> + {
> + if (*d != 0)
> + a = *e;
> +
> + e = &b;
> + y = 0;
> + }
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
