https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116647
Bug ID: 116647 Summary: Internal compiler error in operator[], at vec.h:910 Product: gcc Version: 15.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: yunboni at smail dot nju.edu.cn Target Milestone: --- Created attachment 59079 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59079&action=edit The preprocessed file when using -O3 When I run the following code with -O3 flag, it went crash: ```c int a; char b; long c, d, e; unsigned long f; long g() { if (a <= 0) return 1; for (; d; d++) { e = 0; for (; e < a; e++) { unsigned long h = 0; switch (b) case 2: if (e) h = 5; c += h; } } c /= f; } ``` The full backtrace is: 0x24c4b25 diagnostic_context::diagnostic_impl(rich_location*, diagnostic_metadata const*, int, char const*, __va_list_tag (*) [1], diagnostic_t) ???:0 0x24d80c5 internal_error(char const*, ...) ???:0 0x99f670 fancy_abort(char const*, int, char const*) ???:0 0x13bd81c vectorizable_reduction(_loop_vec_info*, _stmt_vec_info*, _slp_tree*, _slp_instance*, vec<stmt_info_for_cost, va_heap, vl_ptr>*) ???:0 0x139c223 vect_analyze_stmt(vec_info*, _stmt_vec_info*, bool*, _slp_tree*, _slp_instance*, vec<stmt_info_for_cost, va_heap, vl_ptr>*) ???:0 0x13fc15d vect_slp_analyze_operations(vec_info*) ???:0 0x13ca29b vect_analyze_loop(loop*, vec_info_shared*) ???:0 The gcc version I used is: Using built-in specs. COLLECT_GCC=/home/yunbo/eval/compilers/gcc_latest/bin/gcc COLLECT_LTO_WRAPPER=/home/yunbo/eval/compilers/gcc_latest/libexec/gcc/x86_64-pc-linux-gnu/15.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../configure --disable-multilib --disable-bootstrap --enable-languages=c,c++ --prefix=/home/yunbo/eval/compilers/gcc_latest Thread model: posix Supported LTO compression algorithms: zlib gcc version 15.0.0 20240909 (experimental) (GCC) The details can be found here: https://godbolt.org/z/W8azvcW6d