https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99596
Bug ID: 99596 Summary: arm: internal error in single_pred_edge Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: arnd at linaro dot org Target Milestone: --- I ran into this internal compiler error while building the Linux kernel in random configurations, made a reduced test case: $ arm-linux-gnueabihf-gcc-11 -Os -mtune=xscale -c cfi_cmdset_0002.c during RTL pass: fwprop2 cfi_cmdset_0002.c: In function āiā: cfi_cmdset_0002.c:16:1: internal compiler error: in single_pred_edge, at basic-block.h:350 16 | } | ^ 0x7bf679 single_pred_edge ../../src/gcc/basic-block.h:350 0x7bf679 single_pred ../../src/gcc/basic-block.h:369 0x7bf679 rtl_ssa::function_info::create_degenerate_phi(rtl_ssa::ebb_info*, rtl_ssa::set_info*) ../../src/gcc/rtl-ssa/blocks.cc:535 0x1860f6d rtl_ssa::function_info::finalize_new_accesses(rtl_ssa::insn_change&) ../../src/gcc/rtl-ssa/changes.cc:508 0x18617c3 rtl_ssa::function_info::change_insns(array_slice<rtl_ssa::insn_change*>) ../../src/gcc/rtl-ssa/changes.cc:659 0x1862078 rtl_ssa::function_info::change_insn(rtl_ssa::insn_change&) ../../src/gcc/rtl-ssa/changes.cc:717 0x172f1cd try_fwprop_subst_pattern ../../src/gcc/fwprop.c:552 0x172f1cd try_fwprop_subst ../../src/gcc/fwprop.c:625 0x172f73e forward_propagate_and_simplify ../../src/gcc/fwprop.c:823 0x172f73e forward_propagate_into ../../src/gcc/fwprop.c:883 0x172fb8a forward_propagate_into ../../src/gcc/fwprop.c:835 0x172fb8a fwprop_insn ../../src/gcc/fwprop.c:954 0x172fc49 fwprop ../../src/gcc/fwprop.c:992 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <file:///usr/share/doc/gcc-11/README.Bugs> for instructions. $ cat cfi_cmdset_0002.c register int a asm("sp"); extern int b; typedef struct { long c[16 * 8 / 32]; } d; int e; int f; int g; d h; int j(int, int, int, d); int i(void) { for (;;) { b &&j(e, f, g, h); j(e, f, g, h); } } $ arm-linux-gnueabihf-gcc-11 --version arm-linux-gnueabihf-gcc-11 (Ubuntu 11-20210310-1ubuntu1) 11.0.1 20210310 (experimental) [master revision 8dc225d311e:2453ef06221:5987d8a79cda1069c774e5c302d5597310270026]