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| author | Andrew Pinski <apinski@marvell.com> | 2021-07-08 19:23:35 -0700 |
|---|---|---|
| committer | Andrew Pinski <apinski@marvell.com> | 2021-07-12 09:29:23 -0700 |
| commit | 3f2338b4706cdc53ab276b9a5fed7f6927404f07 (patch) | |
| tree | b8da0a21805622c8d1557ac9b074e0bfb7fc6e3c /gcc/tree-ssa-phiopt.c | |
| parent | 47113773456ade7324c5467511d97f36cced57b4 (diff) | |
| download | gcc-3f2338b4706cdc53ab276b9a5fed7f6927404f07.zip gcc-3f2338b4706cdc53ab276b9a5fed7f6927404f07.tar.gz gcc-3f2338b4706cdc53ab276b9a5fed7f6927404f07.tar.bz2 | |
[PHIOPT/MATCH] Remove the statement to move if not used
Instead of waiting for DCE to remove the unused statement,
and maybe optimize another conditional, it is better if
we don't move the statement and have the statement
removed.
OK? Bootstrapped and tested on x86_64-linux-gnu.
Changes from v1:
* v2: Change the order of insertation and check to see if the lhs
is used rather than see if the lhs was used in the sequence.
gcc/ChangeLog:
* tree-ssa-phiopt.c (match_simplify_replacement): Move
insert of the sequence before the movement of the
statement. Check if to see if the statement is used
outside of the original phi to see if we should move it.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr96928-1.c: Update to similar as pr96928.c.
Diffstat (limited to 'gcc/tree-ssa-phiopt.c')
| -rw-r--r-- | gcc/tree-ssa-phiopt.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index 7a98b7a..c6adbbd 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -1020,7 +1020,16 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, return false; gsi = gsi_last_bb (cond_bb); - if (stmt_to_move) + /* Insert the sequence generated from gimple_simplify_phiopt. */ + if (seq) + gsi_insert_seq_before (&gsi, seq, GSI_CONTINUE_LINKING); + + /* If there was a statement to move and the result of the statement + is going to be used, move it to right before the original + conditional. */ + if (stmt_to_move + && (gimple_assign_lhs (stmt_to_move) == result + || !has_single_use (gimple_assign_lhs (stmt_to_move)))) { if (dump_file && (dump_flags & TDF_DETAILS)) { @@ -1032,8 +1041,6 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, gsi_move_before (&gsi1, &gsi); reset_flow_sensitive_info (gimple_assign_lhs (stmt_to_move)); } - if (seq) - gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); replace_phi_edge_with_variable (cond_bb, e1, phi, result); |