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| author | Richard Biener <rguenther@suse.de> | 2022-07-04 14:58:41 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-07-05 12:55:32 +0200 |
| commit | 7f4028ae9bbbd35bff34738d5e2f9b6810242ba7 (patch) | |
| tree | e78e8064e82f007e6c4ee01a7b6ff34856f6644b /gcc | |
| parent | 510ac273a785361f7c8f24e4815bfb477a6a2e07 (diff) | |
| download | gcc-7f4028ae9bbbd35bff34738d5e2f9b6810242ba7.zip gcc-7f4028ae9bbbd35bff34738d5e2f9b6810242ba7.tar.gz gcc-7f4028ae9bbbd35bff34738d5e2f9b6810242ba7.tar.bz2 | |
Maintain LC SSA when doing SVE vectorization
The final loop IV use after the loop has that not in LC SSA
(and inserts not simplified _2 = _3 - 0 stmts). In particular
since it splits the exit edge when there's a virtual PHI in the
destination it breaks virtual LC SSA form (but likely also
non-virtual).
The following properly inserts LC PHIs instead.
2022-07-04 Richard Biener <rguenther@suse.de>
* tree-vect-loop-manip.cc (vect_set_loop_condition_normal):
Maintain LC SSA.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/tree-vect-loop-manip.cc | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc index 5c31f0a..d7410d7 100644 --- a/gcc/tree-vect-loop-manip.cc +++ b/gcc/tree-vect-loop-manip.cc @@ -920,9 +920,22 @@ vect_set_loop_condition_normal (class loop *loop, tree niters, tree step, if (final_iv) { - gassign *assign = gimple_build_assign (final_iv, MINUS_EXPR, - indx_after_incr, init); - gsi_insert_on_edge_immediate (single_exit (loop), assign); + gassign *assign; + edge exit = single_exit (loop); + gcc_assert (single_pred_p (exit->dest)); + tree phi_dest + = integer_zerop (init) ? final_iv : copy_ssa_name (indx_after_incr); + /* Make sure to maintain LC SSA form here and elide the subtraction + if the value is zero. */ + gphi *phi = create_phi_node (phi_dest, exit->dest); + add_phi_arg (phi, indx_after_incr, exit, UNKNOWN_LOCATION); + if (!integer_zerop (init)) + { + assign = gimple_build_assign (final_iv, MINUS_EXPR, + phi_dest, init); + gimple_stmt_iterator gsi = gsi_after_labels (exit->dest); + gsi_insert_before (&gsi, assign, GSI_SAME_STMT); + } } return cond_stmt; |