@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-phinodes.h"
#include "tree-ssa.h"
#include "tree-ssa-threadupdate.h"
+#include "ssa-iterators.h"
#include "dumpfile.h"
#include "cfgloop.h"
#include "hash-table.h"
@@ -337,6 +338,31 @@ lookup_redirection_data (edge e, enum insert_option insert)
}
}
+/* Similar to copy_phi_args, except that the PHI arg exists, it just
+ does not have a value associated with it. */
+
+static void
+copy_phi_arg_into_existing_phi (edge src_e, edge tgt_e)
+{
+ int src_idx = src_e->dest_idx;
+ int tgt_idx = tgt_e->dest_idx;
+
+ /* Iterate over each PHI in e->dest. */
+ for (gimple_stmt_iterator gsi = gsi_start_phis (src_e->dest),
+ gsi2 = gsi_start_phis (tgt_e->dest);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi), gsi_next (&gsi2))
+ {
+ gimple src_phi = gsi_stmt (gsi);
+ gimple dest_phi = gsi_stmt (gsi2);
+ tree val = gimple_phi_arg_def (src_phi, src_idx);
+ source_location locus = gimple_phi_arg_location (src_phi, src_idx);
+
+ SET_PHI_ARG_DEF (dest_phi, tgt_idx, val);
+ gimple_phi_arg_set_location (dest_phi, tgt_idx, locus);
+ }
+}
+
/* For each PHI in BB, copy the argument associated with SRC_E to TGT_E. */
static void
@@ -418,7 +444,23 @@ create_edge_and_update_destination_phis (struct redirection_data *rd,
copy_phi_args (e->dest, rd->path->last ()->e, e);
}
-/* Wire up the outgoing edges from the duplicate block and
+/* Look through PATH beginning at START and return TRUE if there are
+ any additional blocks that need to be duplicated. Otherwise,
+ return FALSE. */
+static bool
+any_remaining_duplicated_blocks (vec<jump_thread_edge *> *path,
+ unsigned int start)
+{
+ for (unsigned int i = start + 1; i < path->length (); i++)
+ {
+ if ((*path)[i]->type == EDGE_COPY_SRC_JOINER_BLOCK
+ || (*path)[i]->type == EDGE_COPY_SRC_BLOCK)
+ return true;
+ }
+ return false;
+}
+
+/* Wire up the outgoing edges from the duplicate blocks and
update any PHIs as needed. */
void
ssa_fix_duplicate_block_edges (struct redirection_data *rd,
@@ -427,37 +469,77 @@ ssa_fix_duplicate_block_edges (struct redirection_data *rd,
edge e = rd->incoming_edges->e;
vec<jump_thread_edge *> *path = THREAD_PATH (e);
- /* If we were threading through an joiner block, then we want
- to keep its control statement and redirect an outgoing edge.
- Else we want to remove the control statement & edges, then create
- a new outgoing edge. In both cases we may need to update PHIs. */
- if ((*path)[1]->type == EDGE_COPY_SRC_JOINER_BLOCK)
- {
- edge victim;
- edge e2;
-
- /* This updates the PHIs at the destination of the duplicate
- block. */
- update_destination_phis (local_info->bb, rd->dup_blocks[0]);
-
- /* Find the edge from the duplicate block to the block we're
- threading through. That's the edge we want to redirect. */
- victim = find_edge (rd->dup_blocks[0], (*path)[1]->e->dest);
- e2 = redirect_edge_and_branch (victim, path->last ()->e->dest);
- e2->count = path->last ()->e->count;
-
- /* If we redirected the edge, then we need to copy PHI arguments
- at the target. If the edge already existed (e2 != victim case),
- then the PHIs in the target already have the correct arguments. */
- if (e2 == victim)
- copy_phi_args (e2->dest, path->last ()->e, e2);
- }
- else
- {
- remove_ctrl_stmt_and_useless_edges (rd->dup_blocks[0], NULL);
- create_edge_and_update_destination_phis (rd, rd->dup_blocks[0]);
+ for (unsigned int count = 0, i = 1; i < path->length (); i++)
+ {
+ /* If we were threading through an joiner block, then we want
+ to keep its control statement and redirect an outgoing edge.
+ Else we want to remove the control statement & edges, then create
+ a new outgoing edge. In both cases we may need to update PHIs. */
+ if ((*path)[i]->type == EDGE_COPY_SRC_JOINER_BLOCK)
+ {
+ edge victim;
+ edge e2;
+
+ /* This updates the PHIs at the destination of the duplicate
+ block. */
+ update_destination_phis (local_info->bb, rd->dup_blocks[count]);
+
+ /* Find the edge from the duplicate block to the block we're
+ threading through. That's the edge we want to redirect. */
+ victim = find_edge (rd->dup_blocks[count], (*path)[i]->e->dest);
+
+ /* If there are no remaining blocks on the path to duplicate,
+ then redirect VICTIM to the final destination of the jump
+ threading path. */
+ if (!any_remaining_duplicated_blocks (path, i))
+ {
+ e2 = redirect_edge_and_branch (victim, path->last ()->e->dest);
+ e2->count = path->last ()->e->count;
+ /* If we redirected the edge, then we need to copy PHI arguments
+ at the target. If the edge already existed (e2 != victim
+ case), then the PHIs in the target already have the correct
+ arguments. */
+ if (e2 == victim)
+ copy_phi_args (e2->dest, path->last ()->e, e2);
+ }
+ else
+ {
+ /* Redirect VICTIM to the next duplicated block in the path. */
+ e2 = redirect_edge_and_branch (victim, rd->dup_blocks[count + 1]);
+
+ /* We need to update the PHIs in the next duplicated block. We
+ want the new PHI args to have the same value as they had
+ in the source of the next duplicate block.
+
+ Thus, we need to know which edge we traversed into the
+ source of the duplicate. Furthermore, we may have
+ traversed many edges to reach the source of the duplicate.
+
+ Walk through the path starting at element I until we
+ hit an edge marked with EDGE_COPY_SRC_BLOCK. We want
+ the edge from the prior element. */
+ for (unsigned int j = i + 1; j < path->length (); j++)
+ {
+ if ((*path)[j]->type == EDGE_COPY_SRC_BLOCK)
+ {
+ copy_phi_arg_into_existing_phi ((*path)[j - 1]->e, e2);
+ break;
+ }
+ }
+ }
+ count++;
+ }
+ else if ((*path)[i]->type == EDGE_COPY_SRC_BLOCK)
+ {
+ remove_ctrl_stmt_and_useless_edges (rd->dup_blocks[count], NULL);
+ create_edge_and_update_destination_phis (rd, rd->dup_blocks[count]);
+ if (count == 1)
+ single_succ_edge (rd->dup_blocks[1])->aux = NULL;
+ count++;
+ }
}
}
+
/* Hash table traversal callback routine to create duplicate blocks. */
int