https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123822
Bug ID: 123822
Summary: [15/16 Regression] ICE: in gen_rtx_SUBREG, at
emit-rtl.cc:1032 at -Ofast with _Decimal64 vector
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: aarch64-unknown-linux-gnu
Created attachment 63489
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63489&action=edit
reduced testcase
Compiler output:
$ aarch64-unknown-linux-gnu-gcc -Ofast testcase.c
during RTL pass: combine
testcase.c: In function 'foo':
testcase.c:10:1: internal compiler error: in gen_rtx_SUBREG, at
emit-rtl.cc:1048
10 | }
| ^
0x283d75d internal_error(char const*, ...)
/repo/gcc-trunk/gcc/diagnostic-global-context.cc:787
0xc9996f fancy_abort(char const*, int, char const*)
/repo/gcc-trunk/gcc/diagnostics/context.cc:1812
0x85ba80 gen_rtx_SUBREG(machine_mode, rtx_def*, poly_int<2u, unsigned long>)
/repo/gcc-trunk/gcc/emit-rtl.cc:1048
0x85ba80 gen_rtx_SUBREG(machine_mode, rtx_def*, poly_int<2u, unsigned long>)
/repo/gcc-trunk/gcc/emit-rtl.cc:1046
0x14998f2 simplify_context::simplify_subreg(machine_mode, rtx_def*,
machine_mode, poly_int<2u, unsigned long>)
/repo/gcc-trunk/gcc/simplify-rtx.cc:8466
0x2566e8c simplify_subreg(machine_mode, rtx_def*, machine_mode, poly_int<2u,
unsigned long>)
/repo/gcc-trunk/gcc/rtl.h:3582
0x2566e8c combine_simplify_rtx
/repo/gcc-trunk/gcc/combine.cc:5977
0x2569047 subst
/repo/gcc-trunk/gcc/combine.cc:5660
0x2568ea6 subst
/repo/gcc-trunk/gcc/combine.cc:5587
0x256d4ab try_combine
/repo/gcc-trunk/gcc/combine.cc:3357
0x25751f2 combine_instructions
/repo/gcc-trunk/gcc/combine.cc:1293
0x25751f2 rest_of_handle_combine
/repo/gcc-trunk/gcc/combine.cc:15233
0x25751f2 execute
/repo/gcc-trunk/gcc/combine.cc:15277
/repo/gcc-trunk/binary-trunk-20260125011627-r16-7020-g5bfcdd5c59adb4-checking-yes-rtl-df-extra-aarch64/bin/../libexec/gcc/aarch64-unknown-linux-gnu/16.0.1/cc1
-quiet -iprefix
/repo/gcc-trunk/binary-trunk-20260125011627-r16-7020-g5bfcdd5c59adb4-checking-yes-rtl-df-extra-aarch64/bin/../lib/gcc/aarch64-unknown-linux-gnu/16.0.1/
testcase.c -quiet -dumpdir a- -dumpbase testcase.c -dumpbase-ext .c
-mlittle-endian -mabi=lp64 -Ofast -o /tmp/ccvoCLl2.s
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
$ aarch64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-aarch64/bin/aarch64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-20260125011627-r16-7020-g5bfcdd5c59adb4-checking-yes-rtl-df-extra-aarch64/bin/../libexec/gcc/aarch64-unknown-linux-gnu/16.0.1/lto-wrapper
Target: aarch64-unknown-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--enable-libsanitizer --with-sysroot=/usr/aarch64-unknown-linux-gnu
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=aarch64-unknown-linux-gnu
--with-ld=/usr/bin/aarch64-unknown-linux-gnu-ld
--with-as=/usr/bin/aarch64-unknown-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-20260125011627-r16-7020-g5bfcdd5c59adb4-checking-yes-rtl-df-extra-aarch64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.1 20260125 (experimental) (GCC)
