https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98791
Bug ID: 98791 Summary: ICE in paradoxical_subreg_p (in ira) with SVE, LTO Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: acoplan at gcc dot gnu.org Target Milestone: --- The following fails: $ cat test.c extern char a[]; extern long b[]; void c(unsigned d, unsigned long long g[][13]) { for (int f = 0; f < 24; f += d - 45810) { a[f] = g[0][2]; b[f] = 0; } } static unsigned long long e[1][13]; int main() { c(45811, e); } $ aarch64-elf-gcc -flto -O1 -ftree-vectorize -march=armv8.2-a+sve --param=aarch64-autovec-preference=3 test.c during RTL pass: ira test.c: In function 'main': test.c:10:27: internal compiler error: in paradoxical_subreg_p, at rtl.h:3170 10 | int main() { c(45811, e); } | ^ 0xab2093 paradoxical_subreg_p(machine_mode, machine_mode) /home/alecop01/toolchain/src/gcc/gcc/rtl.h:3170 0xab2093 narrower_subreg_mode(machine_mode, machine_mode) /home/alecop01/toolchain/src/gcc/gcc/rtl.h:3200 0xab2093 update_costs_from_allocno /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:1410 0xab26c5 update_costs_from_copies /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:1480 0xab3790 assign_hard_reg /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:1971 0xabc506 pop_allocnos_from_stack /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:2707 0xabc506 color_allocnos /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:3251 0xabc506 color_pass /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:3363 0xaa5ab6 ira_traverse_loop_tree(bool, ira_loop_tree_node*, void (*)(ira_loop_tree_node*), void (*)(ira_loop_tree_node*)) /home/alecop01/toolchain/src/gcc/gcc/ira-build.c:1776 0xab8649 do_coloring /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:3514 0xab8649 color /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:4885 0xab8649 ira_color() /home/alecop01/toolchain/src/gcc/gcc/ira-color.c:5014 0xa9f999 ira /home/alecop01/toolchain/src/gcc/gcc/ira.c:5654 0xa9f999 execute /home/alecop01/toolchain/src/gcc/gcc/ira.c:5964 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. lto-wrapper: fatal error: aarch64-elf-gcc returned 1 exit status compilation terminated. /home/alecop01/toolchain/build-aarch64-elf/install/lib/gcc/aarch64-elf/11.0.0/../../../../aarch64-elf/bin/ld: error: lto-wrapper failed collect2: error: ld returned 1 exit status The backtrace appears to be the same as PR97092, although that PR doesn't appear to have regressed (at least for the original testcase).