http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59285
Bug ID: 59285
Summary: gcc.dg/builtin-unreachable-6.c:17:1: internal compiler
error: in rtl_verify_fallthru, at cfgrtl.c:2862
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: ktkachov at gcc dot gnu.org
The gcc.dg/builtin-unreachable-6.c testcase fails on arm-none-eabi with:
$SRC/gcc/gcc/testsuite/gcc.dg/builtin-unreachable-6.c: In function 'foo':
$SRC/gcc/gcc/testsuite/gcc.dg/builtin-unreachable-6.c:17:1: error:
verify_flow_info: Incorrect fallthru 2->5
$SRC/gcc/gcc/testsuite/gcc.dg/builtin-unreachable-6.c:17:1: error: wrong insn
in the fallthru edge
(barrier 21 20 27)
$SRC/gcc/gcc/testsuite/gcc.dg/builtin-unreachable-6.c:17:1: internal compiler
error: in rtl_verify_fallthru, at cfgrtl.c:2862
0x95d645 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
$SRC/gcc/gcc/rtl-error.c:109
0x69254a rtl_verify_fallthru
$SRC/gcc/gcc/cfgrtl.c:2862
0x69254a rtl_verify_flow_info
$SRC/gcc/gcc/cfgrtl.c:2962
0x681af7 verify_flow_info()
$SRC/gcc/gcc/cfghooks.c:258
0xe5c24f if_convert
$SRC/gcc/gcc/ifcvt.c:4460
0xe5d95d rest_of_handle_if_after_reload
$SRC/gcc/gcc/ifcvt.c:4594
0xe5d95d execute
$SRC/gcc/gcc/ifcvt.c:4625
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
Bisection shows it started with r205074:
* tree-ssa-threadedge.c (thread_across_edge): After threading
through a joiner, allow threading a normal block requiring
duplication.
* tree-ssa-threadupdate.c (thread_block_1): Improve code to detect
jump threading requests that would muck up the loop structures.
