https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110994
Bug ID: 110994
Summary: RISC-V Fortran: Illegal instruction ICE with scalable
autovec
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: jeremy.bennett at embecosm dot com
Target Milestone: ---
Created attachment 55723
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55723&action=edit
Fortran 90 source code of the test case
Discovered by accident when hunting down a RVV bug, but this appears to be
connected with the autovectorizer generically rather than specifically the
RISC-V vector ISA extension.
The following code (testcase.f90) causes an ICE when using RISC-V as target
with
--param=riscv-autovec-preference=scalable.
SUBROUTINE d(e) f
(this is invalid Fortran 90, but it should still not trigger an ICE)
Compiled with:
riscv64-unknown-linux-gnu-gfortran -march=rv64gc -mabi=lp64d -c \
-Ofast --param=riscv-autovec-preference=scalable testcase.f90
Output is:
f951: internal compiler error: Illegal instruction
0x112a263 crash_signal
/home/jeremy/gittrees/mustang/gcc/gcc/toplev.cc:314
0x7f0d57e3c4af ???
./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0x9342a9 poly_int_pod<2u, unsigned short>::to_constant() const
/home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv.cc:6565
0x9342a9 riscv_hard_regno_nregs
/home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv.cc:6578
0x1092519 init_reg_modes_target()
/home/jeremy/gittrees/mustang/gcc/gcc/reginfo.cc:466
0xd00827 init_emit_regs()
/home/jeremy/gittrees/mustang/gcc/gcc/emit-rtl.cc:6072
0x9e6058 backend_init
/home/jeremy/gittrees/mustang/gcc/gcc/toplev.cc:1749
0x9e6058 do_compile
/home/jeremy/gittrees/mustang/gcc/gcc/toplev.cc:2108
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.
System information
------------------
Using built-in specs.
COLLECT_GCC=riscv64-unknown-linux-gnu-gfortran
COLLECT_LTO_WRAPPER=/home/jeremy/gittrees/mustang/install/libexec/gcc/riscv64-unknown-linux-gnu/14.0.0/lto-wrapper
Target: riscv64-unknown-linux-gnu
Configured with: /home/jeremy/gittrees/mustang/gcc/configure
--target=riscv64-unknown-linux-gnu
--prefix=/home/jeremy/gittrees/mustang/install
--with-sysroot=/home/jeremy/gittrees/mustang/install/sysroot
--with-pkgversion=g68783211f66 --with-system-zlib --enable-shared --enable-tls
--enable-languages=c,c++,fortran --disable-libmudflap --disable-libssp
--disable-libquadmath --disable-libsanitizer --disable-nls --disable-bootstrap
--src=/home/jeremy/gittrees/mustang/gcc --enable-multilib --with-abi=lp64d
--with-arch=rv64gc --with-tune= --with-isa-spec=20191213 'CFLAGS_FOR_TARGET=-O2
-mcmodel=medany' 'CXXFLAGS_FOR_TARGET=-O2 -mcmodel=medany'
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230811 (experimental) (g68783211f66)
