https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68844
Bug ID: 68844
Summary: [6 regression] gcc.dg/tree-ssa/ssa-dom-thread-4.c
fails since r228306
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: wschmidt at gcc dot gnu.org
CC: law at gcc dot gnu.org, seurer at linux dot vnet.ibm.com
Target Milestone: ---
Host: powerpc64-*-linux*
Target: powerpc64*-*-linux*
Build: powerpc64*-*-linux*
Created attachment 36986
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36986&action=edit
dom1 dump from r228305
The subject test case has been failing as follows:
FAIL: gcc.dg/tree-ssa/ssa-dom-thread-4.c scan-tree-dump-times dom1 "Threaded" 4
since r228306, which is:
2015-09-30 Jeff Law <l...@redhat.com>
* tree-ssa-dom.c (optimize_stmt): Collapse control flow statements
with constant conditions.
* tree-ssa-threadupdate.c (remove_jump_threads_starting_at): New.
(remove_ctrl_stmt_and_useless_edges): No longer static.
* tree-ssa-threadupdate.h (remove_jump_threads_starting_at): Prototype.
(remove_ctrl_stmt_and_useless_edges): Likewise.
My guess is that the test case just needs adjusting because the control flow
has changed sufficiently to remove some jump-threading opportunities, but I'm
not familiar enough with the code to be sure. Jeff, would you mind taking a
quick look?
The removed threaded jumps are:
Threaded jump 15 --> 3 to 22
Threaded jump 5 --> 18 to 23
Threaded jump 7 --> 18 to 23
Attaching the dom1 dumps from r228305 and r228306.
Apologies if this is a known issue, but I couldn't find a PR open on it.
