https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116131
Bug ID: 116131
Summary: [14/15 Regression] RISC-V: Unrecognizable insn with
xtheadmemidx
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: patrick at rivosinc dot com
Target Milestone: ---
Testcase:
volatile long long a;
int b;
int c[1];
void d() { c[a] = b; }
Command/backtrace:
> /scratch/tc-testing/tc-compiler-fuzz-trunk/build-gcv/bin/riscv64-unknown-linux-gnu-gcc
> -march=rv32ixtheadmemidx -mabi=ilp32 -O1 red.c -c -S -o /dev/null
red.c: In function 'd':
red.c:4:22: error: unrecognizable insn:
4 | void d() { c[a] = b; }
| ^
(insn 17 13 0 2 (set (mem:SI (plus:SI (reg/f:SI 141)
(ashift:SI (subreg:SI (reg:DI 134 [ a.0_1 ]) 0)
(const_int 2 [0x2]))) [0 S4 A32])
(reg:SI 143 [ b ])) "red.c":4:17 -1
(nil))
during RTL pass: subreg3
red.c:4:22: internal compiler error: in extract_insn, at recog.cc:2848
0x2ddf545 internal_error(char const*, ...)
../../../gcc/gcc/diagnostic-global-context.cc:491
0xc4f10e fancy_abort(char const*, int, char const*)
../../../gcc/gcc/diagnostic.cc:1755
0xae2985 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
../../../gcc/gcc/rtl-error.cc:108
0xae29a7 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
../../../gcc/gcc/rtl-error.cc:116
0xae125b extract_insn(rtx_insn*)
../../../gcc/gcc/recog.cc:2848
0x2800737 decompose_multiword_subregs
../../../gcc/gcc/lower-subreg.cc:1584
0x28016f1 execute
../../../gcc/gcc/lower-subreg.cc:1849
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.
Godbolt: https://godbolt.org/z/Gc1a5Mxfd
Found via fuzzer.
