From fc7a3a00ad5089bd13f7e4646f7a319e7eee407c Mon Sep 17 00:00:00 2001 From: law Date: Tue, 22 Dec 2015 21:49:12 +0000 Subject: [PATCH] [PATCH] Avoid unnecessary block copying in path splitting * gimple-ssa-split-paths.c (split_paths): Avoid unnecessary block copying. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@231915 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 5 +++++ gcc/gimple-ssa-split-paths.c | 9 ++++----- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 73ab7d4..5e1e819 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2015-12-22 Jeff Law + + * gimple-ssa-split-paths.c (split_paths): Avoid unnecessary block + copying. + 2015-12-22 Jakub Jelinek PR c++/67376 diff --git a/gcc/gimple-ssa-split-paths.c b/gcc/gimple-ssa-split-paths.c index 540fdf3..294a1af 100644 --- a/gcc/gimple-ssa-split-paths.c +++ b/gcc/gimple-ssa-split-paths.c @@ -192,9 +192,10 @@ split_paths () /* BB is the merge point for an IF-THEN-ELSE we want to transform. - Essentially we want to create two duplicates of BB and append - a duplicate to the THEN and ELSE clauses. This will split the - path leading to the latch. BB will be unreachable and removed. */ + Essentially we want to create a duplicate of bb and redirect the + first predecessor of BB to the duplicate (leaving the second + predecessor as is. This will split the path leading to the latch + re-using BB to avoid useless copying. */ if (bb && is_feasible_trace (bb)) { if (dump_file && (dump_flags & TDF_DETAILS)) @@ -202,9 +203,7 @@ split_paths () "Duplicating join block %d into predecessor paths\n", bb->index); basic_block pred0 = EDGE_PRED (bb, 0)->src; - basic_block pred1 = EDGE_PRED (bb, 1)->src; transform_duplicate (pred0, bb); - transform_duplicate (pred1, bb); changed = true; } } -- 2.7.4