https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112816
Bug ID: 112816 Summary: internal compiler error: in extract_insn, at recog.cc:2804, unrecognizable_insn for __builtin_signbit Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end Assignee: unassigned at gcc dot gnu.org Reporter: a.elovikov at gmail dot com Target Milestone: --- https://godbolt.org/z/3vzejjWcq constexpr int N = 4; template <typename T> struct S { T x[N]; T& operator[](int idx) { return x[idx]; } }; auto foo(S<float> x) { S<int> res; for (int i = 0; i < 4; ++i) res[i] = __builtin_signbit(x[i]) ? -1 : 0; return res; } Copy-pasting "x86-64 gcc (trunk)" output from the godbolt link above (-O3 -std=c++17 options used): <source>: In function 'auto foo(S<float>)': <source>:13:1: error: unrecognizable insn: 13 | } | ^ (insn 20 19 21 2 (set (reg:V4SI 99 [ vect__2.11 ]) (lshiftrt:V4SI (subreg:V4SI (subreg:V4SF (reg/v:TI 105 [ x ]) 0) 0) (const_int 31 [0x1f]))) "<source>":11:31 discrim 1 -1 (nil)) during RTL pass: vregs <source>:13:1: internal compiler error: in extract_insn, at recog.cc:2804 0x26c14fe internal_error(char const*, ...) ???:0 0xb125b9 fancy_abort(char const*, int, char const*) ???:0 0x925e6a _fatal_insn(char const*, rtx_def const*, char const*, int, char const*) ???:0 0x925e8c _fatal_insn_not_found(rtx_def const*, char const*, int, char const*) ???:0 Please submit a full bug report, with preprocessed source (by using -freport-bug). Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. Compiler returned: 1 Also reproducible with (the version I discovered it with) $ g++ --version g++ (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0 Copyright (C) 2021 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.