https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120693
Bug ID: 120693 Summary: [16 Regression] ICE: during GIMPLE pass: modref Product: gcc Version: 16.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: ipa Assignee: unassigned at gcc dot gnu.org Reporter: ewlu at rivosinc dot com Target Milestone: --- Testcase: extern _Bool a[][1]; void b(short c, long d[][11]) { for (long e = 0; e < 1; e += -3184629396648244933) a[e][e] = c ? d[e][e] : 0; } Godbolt: https://godbolt.org/z/ff9v3388j Found while fuzzing for riscv64. riscv command/backtrace: $ /scratch/ewlu/daily-upstream-build/build-gcv/bin/riscv64-unknown-linux-gnu-gcc -I/scratch/ewlu/ci/compiler-fuzz-ci/csmith-build/include -fsigned-char -fno-strict-aliasing -fwrapv -O3 red.c -o rv64gcv.out -w -frepo rt-bug during GIMPLE pass: modref red.c: In function 'b': red.c:2:6: internal compiler error: in merge, at ipa-modref-tree.cc:176 2 | void b(short c, long d[][11]) { | ^ 0x2e17566 internal_error(char const*, ...) ../../../gcc/gcc/diagnostic-global-context.cc:517 0xd0f517 fancy_abort(char const*, int, char const*) ../../../gcc/gcc/diagnostic.cc:1803 0xb60725 modref_access_node::merge(modref_access_node const&, bool) ../../../gcc/gcc/ipa-modref-tree.cc:176 0x1224c14 modref_access_node::try_merge_with(vec<modref_access_node, va_gc, vl_embed>*&, unsigned long) ../../../gcc/gcc/ipa-modref-tree.cc:457 0x122684e modref_access_node::insert(vec<modref_access_node, va_gc, vl_embed>*&, modref_access_node, unsigned long, bool) ../../../gcc/gcc/ipa-modref-tree.cc:562 0x12215d2 modref_ref_node<int>::insert_access(modref_access_node, unsigned long, bool) ../../../gcc/gcc/ipa-modref-tree.h:194 0x12215d2 modref_tree<int>::insert(unsigned int, unsigned int, unsigned int, int, int, modref_access_node, bool) ../../../gcc/gcc/ipa-modref-tree.h:444 0x12137a3 modref_tree<int>::insert(tree_node*, int, int, modref_access_node const&, bool) ../../../gcc/gcc/ipa-modref-tree.h:471 0x12137a3 record_access ../../../gcc/gcc/ipa-modref.cc:1086 0x12141e9 analyze_load ../../../gcc/gcc/ipa-modref.cc:1721 0x11503d4 walk_stmt_load_store_addr_ops(gimple*, void*, bool (*)(gimple*, tree_node*, tree_node*, void*), bool (*)(gimple*, tree_node*, tree_node*, void*), bool (*)(gimple*, tree_node*, tree_node*, void*)) ../../../gcc/gcc/gimple-walk.cc:825 0x121a90d analyze_stmt ../../../gcc/gcc/ipa-modref.cc:1801 0x121c1cf analyze ../../../gcc/gcc/ipa-modref.cc:1914 0x121c1cf analyze_function ../../../gcc/gcc/ipa-modref.cc:3241 0x121d99e execute ../../../gcc/gcc/ipa-modref.cc:4262 Please submit a full bug report, with preprocessed source. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. Found via fuzzer