https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70442
Bug ID: 70442
Summary: gcc ICE at -O2 and above on valid code on
x86_64-linux-gnu in "extract_insn"
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: helloqirun at gmail dot com
Target Milestone: ---
The following valid code causes an ICE when compiled with the current gcc trunk
at -O2 and above on x86_64-linux-gnu in both 32-bit mode only.
It should be a 6 regression.
$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 6.0.0 20160329 (experimental) [trunk revision 234517] (GCC)
$ gcc-trunk -m32 -O2 abc.c
abc.c: In function ‘fn1’:
abc.c:11:1: error: unrecognizable insn:
}
^
(insn 17 16 27 2 (set (subreg:V2DI (reg/v:DI 92 [ b ]) 0)
(reg/v:DI 87 [ b ])) abc.c:9 -1
(expr_list:REG_DEAD (reg/v:DI 87 [ b ])
(nil)))
abc.c:11:1: internal compiler error: in extract_insn, at recog.c:2287
0xaf5528 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
../../gcc/gcc/rtl-error.c:108
0xaf5559 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
../../gcc/gcc/rtl-error.c:116
0xac2721 extract_insn(rtx_insn*)
../../gcc/gcc/recog.c:2287
0x1276dbe decompose_multiword_subregs
../../gcc/gcc/lower-subreg.c:1465
0x127803d execute
../../gcc/gcc/lower-subreg.c:1735
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.
$ cat abc.c
char a, c;
void fn1() {
long long b;
long m;
int d;
switch (d)
case 5:
b = a;
b ^= m;
c = b >> b;
}
