https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121983
Bug ID: 121983
Summary: [16 Regression] ICE: RTL check: expected code 'reg',
have 'subreg' in rhs_regno, at rtl.h:1946 with -O2
-mcpu=xiangshan-nanhu
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: riscv64-unknown-linux-gnu
Created attachment 62407
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62407&action=edit
reduced testcase
This might need RTL checking enabled.
Compiler output:
$ riscv64-unknown-linux-gnu-gcc -O2 -mcpu=xiangshan-nanhu testcase.c
during RTL pass: sched1
testcase.c: In function 'foo':
testcase.c:12:1: internal compiler error: RTL check: expected code 'reg', have
'subreg' in rhs_regno, at rtl.h:1946
12 | }
| ^
0x33604cc internal_error(char const*, ...)
/repo/gcc-trunk/gcc/diagnostic-global-context.cc:786
0xc2e16f rtl_check_failed_code1(rtx_def const*, rtx_code, char const*, int,
char const*)
/repo/gcc-trunk/gcc/rtl.cc:770
0xce9605 rhs_regno(rtx_def const*)
/repo/gcc-trunk/gcc/rtl.h:1946
0xcf1127 rhs_regno(rtx_def const*)
/repo/gcc-trunk/gcc/config/riscv/riscv.cc:10380
0xcf1127 riscv_macro_fusion_pair_p
/repo/gcc-trunk/gcc/config/riscv/riscv.cc:10379
0x325e08f sched_macro_fuse_insns
/repo/gcc-trunk/gcc/sched-deps.cc:2877
0x325e08f sched_analyze_insn
/repo/gcc-trunk/gcc/sched-deps.cc:2916
0x325ed39 deps_analyze_insn(deps_desc*, rtx_insn*)
/repo/gcc-trunk/gcc/sched-deps.cc:3707
0x3261efa sched_analyze(deps_desc*, rtx_insn*, rtx_insn*)
/repo/gcc-trunk/gcc/sched-deps.cc:3860
0x182a5bf compute_block_dependences
/repo/gcc-trunk/gcc/sched-rgn.cc:2738
0x182a5bf sched_rgn_compute_dependencies(int)
/repo/gcc-trunk/gcc/sched-rgn.cc:3377
0x182cfa8 schedule_region
/repo/gcc-trunk/gcc/sched-rgn.cc:3149
0x182cfa8 schedule_insns()
/repo/gcc-trunk/gcc/sched-rgn.cc:3535
0x182d5fc schedule_insns()
/repo/gcc-trunk/gcc/sched-rgn.cc:3521
0x182d5fc rest_of_handle_sched
/repo/gcc-trunk/gcc/sched-rgn.cc:3739
0x182d5fc execute
/repo/gcc-trunk/gcc/sched-rgn.cc:3849
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.
$ riscv64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-riscv64/bin/riscv64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-20250917113826-r16-3928-gd81e24bbb930e2-checking-yes-rtl-df-extra-riscv64/bin/../libexec/gcc/riscv64-unknown-linux-gnu/16.0.0/lto-wrapper
Target: riscv64-unknown-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-isa-spec=2.2 --with-sysroot=/usr/riscv64-unknown-linux-gnu
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=riscv64-unknown-linux-gnu
--with-ld=/usr/bin/riscv64-unknown-linux-gnu-ld
--with-as=/usr/bin/riscv64-unknown-linux-gnu-as --disable-multilib
--enable-libsanitizer --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-20250917113826-r16-3928-gd81e24bbb930e2-checking-yes-rtl-df-extra-riscv64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.0 20250917 (experimental) (GCC)
