diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/tree-parloops.c | 45 |
2 files changed, 41 insertions, 12 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7dee74d..28022d7 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,13 @@ 2015-07-07 Tom de Vries <tom@codesourcery.com> + PR tree-optimization/66642 + * tree-parloops.c (transform_to_exit_first_loop_alt): Update function + header comment. Rename split_edge variable to edge_at_split. Split + exit edge to create new loop exit bb. Insert loop exit phis in new loop + exit bb. + +2015-07-07 Tom de Vries <tom@codesourcery.com> + * tree-cfg.c (get_virtual_phi): New function. * tree-cfg.h (get_virtual_phi): Declare. * tree-ssa-loop-manip.c (replace_uses_in_dominated_bbs) diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c index 4a2757d..aecee69 100644 --- a/gcc/tree-parloops.c +++ b/gcc/tree-parloops.c @@ -1516,7 +1516,7 @@ replace_uses_in_bb_by (tree name, tree val, basic_block bb) goto <bb header> <bb exit>: - sum_z = PHI <sum_b (cond[1])> + sum_z = PHI <sum_b (cond[1]), ...> [1] Where <bb cond> is single_pred (bb latch); In the simplest case, that's <bb header>. @@ -1543,14 +1543,17 @@ replace_uses_in_bb_by (tree name, tree val, basic_block bb) if (ivtmp_c < n + 1) goto <bb header>; else - goto <bb exit>; + goto <bb newexit>; <bb latch>: ivtmp_b = ivtmp_a + 1; goto <bb newheader> + <bb newexit>: + sum_y = PHI <sum_c (newheader)> + <bb exit>: - sum_z = PHI <sum_c (newheader)> + sum_z = PHI <sum_y (newexit), ...> In unified diff format: @@ -1587,9 +1590,12 @@ replace_uses_in_bb_by (tree name, tree val, basic_block bb) - goto <bb header> + goto <bb newheader> ++ <bb newexit>: ++ sum_y = PHI <sum_c (newheader)> + <bb exit>: -- sum_z = PHI <sum_b (cond[1])> -+ sum_z = PHI <sum_c (newheader)> +- sum_z = PHI <sum_b (cond[1]), ...> ++ sum_z = PHI <sum_y (newexit), ...> Note: the example does not show any virtual phis, but these are handled more or less as reductions. @@ -1620,7 +1626,7 @@ transform_to_exit_first_loop_alt (struct loop *loop, /* Create the new_header block. */ basic_block new_header = split_block_before_cond_jump (exit->src); - edge split_edge = single_pred_edge (new_header); + edge edge_at_split = single_pred_edge (new_header); /* Redirect entry edge to new_header. */ edge entry = loop_preheader_edge (loop); @@ -1637,9 +1643,9 @@ transform_to_exit_first_loop_alt (struct loop *loop, e = redirect_edge_and_branch (post_cond_edge, header); gcc_assert (e == post_cond_edge); - /* Redirect split_edge to latch. */ - e = redirect_edge_and_branch (split_edge, latch); - gcc_assert (e == split_edge); + /* Redirect edge_at_split to latch. */ + e = redirect_edge_and_branch (edge_at_split, latch); + gcc_assert (e == edge_at_split); /* Set the new loop bound. */ gimple_cond_set_rhs (cond_stmt, bound); @@ -1691,21 +1697,36 @@ transform_to_exit_first_loop_alt (struct loop *loop, /* Set the latch arguments of the new phis to ivtmp/sum_b. */ flush_pending_stmts (post_inc_edge); - /* Register the reduction exit phis. */ + /* Create a new empty exit block, inbetween the new loop header and the old + exit block. The function separate_decls_in_region needs this block to + insert code that is active on loop exit, but not any other path. */ + basic_block new_exit_block = split_edge (exit); + + /* Insert and register the reduction exit phis. */ for (gphi_iterator gsi = gsi_start_phis (exit_block); !gsi_end_p (gsi); gsi_next (&gsi)) { gphi *phi = gsi.phi (); tree res_z = PHI_RESULT (phi); + + /* Now that we have a new exit block, duplicate the phi of the old exit + block in the new exit block to preserve loop-closed ssa. */ + edge succ_new_exit_block = single_succ_edge (new_exit_block); + edge pred_new_exit_block = single_pred_edge (new_exit_block); + tree res_y = copy_ssa_name (res_z, phi); + gphi *nphi = create_phi_node (res_y, new_exit_block); + tree res_c = PHI_ARG_DEF_FROM_EDGE (phi, succ_new_exit_block); + add_phi_arg (nphi, res_c, pred_new_exit_block, UNKNOWN_LOCATION); + add_phi_arg (phi, res_y, succ_new_exit_block, UNKNOWN_LOCATION); + if (virtual_operand_p (res_z)) continue; - tree res_c = PHI_ARG_DEF_FROM_EDGE (phi, exit); gimple reduc_phi = SSA_NAME_DEF_STMT (res_c); struct reduction_info *red = reduction_phi (reduction_list, reduc_phi); if (red != NULL) - red->keep_res = phi; + red->keep_res = nphi; } /* We're going to cancel the loop at the end of gen_parallel_loop, but until |