https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100212
Bug ID: 100212
Summary: Shift by-1 in aarch64_classify_index
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: acoplan at gcc dot gnu.org
Target Milestone: ---
Bootstrapping on aarch64 --with-build-config=bootstrap-ubsan shows the
following issue (reduced from gcc.target/aarch64/sve/mask_struct_store_2.c):
$ cat sve_test.c
int *__restrict a;
void b() {
for (int c; c; ++c)
a[c] = a[c * 3];
}
$ gcc/xgcc -B gcc sve_test.c -c -march=armv8.2-a+sve -O -ftree-vectorize
/home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:9556:10: runtime
error: shift exponent -1 is negative
#0 0x2de7d7c in aarch64_classify_index
/home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:9556
#1 0x2deca68 in aarch64_classify_address(aarch64_address_info*, rtx_def*,
machine_mode, bool, aarch64_addr_query_type)
/home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:9781
#2 0x2df2bb8 in aarch64_legitimate_address_hook_p
/home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:9946
#3 0x1c673fc in memory_address_addr_space_p(machine_mode, rtx_def*,
unsigned char) /home/alecop01/toolchain/src/gcc/gcc/recog.c:1793
#4 0x2389da4 in valid_mem_ref_p(machine_mode, unsigned char, mem_address*)
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-address.c:355
#5 0x2500e84 in get_address_cost
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:4675
#6 0x2500e84 in get_computation_cost
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:4881
#7 0x2505f44 in determine_group_iv_cost_address
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:4990
#8 0x2505f44 in determine_group_iv_cost
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:5575
#9 0x2506b40 in determine_group_iv_costs
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:5769
#10 0x251287c in tree_ssa_iv_optimize_loop
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:8034
#11 0x251287c in tree_ssa_iv_optimize()
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop-ivopts.c:8083
#12 0x258c574 in execute
/home/alecop01/toolchain/src/gcc/gcc/tree-ssa-loop.c:513
#13 0x1b5ec1c in execute_one_pass(opt_pass*)
/home/alecop01/toolchain/src/gcc/gcc/passes.c:2567
#14 0x1b623b8 in execute_pass_list_1
/home/alecop01/toolchain/src/gcc/gcc/passes.c:2656
#15 0x1b623f0 in execute_pass_list_1
/home/alecop01/toolchain/src/gcc/gcc/passes.c:2657
#16 0x1b623f0 in execute_pass_list_1
/home/alecop01/toolchain/src/gcc/gcc/passes.c:2657
#17 0x1b624d4 in execute_pass_list(function*, opt_pass*)
/home/alecop01/toolchain/src/gcc/gcc/passes.c:2667
#18 0xc7b2a4 in cgraph_node::expand()
/home/alecop01/toolchain/src/gcc/gcc/cgraphunit.c:1830
#19 0xc7ff24 in expand_all_functions
/home/alecop01/toolchain/src/gcc/gcc/cgraphunit.c:1994
#20 0xc7ff24 in symbol_table::compile()
/home/alecop01/toolchain/src/gcc/gcc/cgraphunit.c:2358
#21 0xc8b81c in symbol_table::compile()
/home/alecop01/toolchain/src/gcc/gcc/cgraphunit.c:2271
#22 0xc8b81c in symbol_table::finalize_compilation_unit()
/home/alecop01/toolchain/src/gcc/gcc/cgraphunit.c:2539
#23 0x1f97478 in compile_file
/home/alecop01/toolchain/src/gcc/gcc/toplev.c:482
#24 0x68d9b0 in do_compile
/home/alecop01/toolchain/src/gcc/gcc/toplev.c:2201
#25 0x68d9b0 in toplev::main(int, char**)
/home/alecop01/toolchain/src/gcc/gcc/toplev.c:2340
#26 0x6910d0 in main /home/alecop01/toolchain/src/gcc/gcc/main.c:39
#27 0xffffb95236dc in __libc_start_main
(/lib/aarch64-linux-gnu/libc.so.6+0x206dc)
#28 0x691b2c (/data/alecop01/builds/bstrap-ubsan/gcc/cc1+0x691b2c)
