From d4c8d5ede1f35643163942af46bcb51d3c03c8d7 Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Mon, 9 Nov 2015 04:57:19 +0100 Subject: [PATCH] Fix bb-reorder problem with degenerate cond_jump (PR68182) The code mistakenly thinks any cond_jump has two successors. This is not true if both destinations are the same, as can happen with weird patterns as in the PR. PR rtl-optimization/68182 * gcc/bb-reorder.c (reorder_basic_blocks_simple): Treat a conditional branch with only one successor just like unconditional branches. From-SVN: r229983 --- gcc/ChangeLog | 8 +++++++- gcc/bb-reorder.c | 6 +++--- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6401c437ed2..dcb6d55ca6b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,4 +1,10 @@ -2015-11-08 Jeff Law +2015-11-09 Segher Boessenkool + + PR rtl-optimization/68182 + * gcc/bb-reorder.c (reorder_basic_blocks_simple): Treat a conditional + branch with only one successor just like unconditional branches. + +2015-11-08 Jeff Law * tree-ssa-threadupdate.c (register_jump_thraed): Assert that a non-FSM path has no edges marked with EDGE_DFS_BACK. diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c index 5f1c2ccc6cb..950b1a1089d 100644 --- a/gcc/bb-reorder.c +++ b/gcc/bb-reorder.c @@ -2304,7 +2304,9 @@ reorder_basic_blocks_simple (void) if (JUMP_P (end) && extract_asm_operands (end)) continue; - if (any_condjump_p (end)) + if (single_succ_p (bb)) + edges[n++] = EDGE_SUCC (bb, 0); + else if (any_condjump_p (end)) { edge e0 = EDGE_SUCC (bb, 0); edge e1 = EDGE_SUCC (bb, 1); @@ -2315,8 +2317,6 @@ reorder_basic_blocks_simple (void) edges[n++] = e0; edges[n++] = e1; } - else if (single_succ_p (bb)) - edges[n++] = EDGE_SUCC (bb, 0); } /* Sort the edges, the most desirable first. When optimizing for size -- 2.30.2