tree-ssa-threadedge.c (thread_around_empty_block): Remove checks for the number of predecessors and successors allowed.
* tree-ssa-threadedge.c (thread_around_empty_block): Remove checks for the number of predecessors and successors allowed. * tree-ssa-threadupdate.c (mark_threaded_blocks): Ignore requests which require copying a joiner block if there is a request which is a subpath that requires no joiner block copying. From-SVN: r202054
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@ -1,3 +1,11 @@
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2013-08-28 Jeff Law <law@redhat.com>
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* tree-ssa-threadedge.c (thread_around_empty_block): Remove
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checks for the number of predecessors and successors allowed.
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* tree-ssa-threadupdate.c (mark_threaded_blocks): Ignore requests
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which require copying a joiner block if there is a request which
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is a subpath that requires no joiner block copying.
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2013-08-28 Jan Hubicka <jh@suse.cz>
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* lto-streamer-out.c (DFS_write_tree_body): Drop
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@ -761,14 +761,6 @@ thread_around_empty_block (edge taken_edge,
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gimple stmt;
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tree cond;
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/* This block must have a single predecessor (E->dest). */
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if (!single_pred_p (bb))
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return NULL;
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/* This block must have more than one successor. */
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if (single_succ_p (bb))
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return NULL;
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/* This block can have no PHI nodes. This is overly conservative. */
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if (!gsi_end_p (gsi_start_phis (bb)))
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return NULL;
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@ -1146,17 +1146,56 @@ mark_threaded_blocks (bitmap threaded_blocks)
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edge e;
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edge_iterator ei;
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/* It is possible to have jump threads in which one is a subpath
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of the other. ie, (A, B), (B, C), (C, D) where B is a joiner
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block and (B, C), (C, D) where no joiner block exists.
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When this occurs ignore the jump thread request with the joiner
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block. It's totally subsumed by the simpler jump thread request.
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This results in less block copying, simpler CFGs. More improtantly,
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when we duplicate the joiner block, B, in this case we will create
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a new threading opportunity that we wouldn't be able to optimize
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until the next jump threading iteration.
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So first convert the jump thread requests which do not require a
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joiner block. */
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for (i = 0; i < threaded_edges.length (); i += 3)
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{
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edge e = threaded_edges[i];
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edge *x = XNEWVEC (edge, 2);
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e->aux = x;
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THREAD_TARGET (e) = threaded_edges[i + 1];
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THREAD_TARGET2 (e) = threaded_edges[i + 2];
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bitmap_set_bit (tmp, e->dest->index);
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if (threaded_edges[i + 2] == NULL)
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{
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edge *x = XNEWVEC (edge, 2);
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e->aux = x;
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THREAD_TARGET (e) = threaded_edges[i + 1];
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THREAD_TARGET2 (e) = NULL;
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bitmap_set_bit (tmp, e->dest->index);
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}
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}
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/* Now iterate again, converting cases where we threaded through
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a joiner block, but ignoring those where we have already
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threaded through the joiner block. */
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for (i = 0; i < threaded_edges.length (); i += 3)
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{
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edge e = threaded_edges[i];
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if (threaded_edges[i + 2] != NULL
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&& threaded_edges[i + 1]->aux == NULL)
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{
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edge *x = XNEWVEC (edge, 2);
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e->aux = x;
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THREAD_TARGET (e) = threaded_edges[i + 1];
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THREAD_TARGET2 (e) = threaded_edges[i + 2];
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bitmap_set_bit (tmp, e->dest->index);
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}
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}
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/* If optimizing for size, only thread through block if we don't have
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to duplicate it or it's an otherwise empty redirection block. */
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if (optimize_function_for_size_p (cfun))
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