https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117142
Bug ID: 117142 Summary: ICE: verify_flow_info failed: error: returns_twice call is not first in basic block 2 at -O1 and above Product: gcc Version: 15.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: iamanonymous.cs at gmail dot com Target Milestone: --- ******************************************************************************* OS and Platform: $ uname -a: Linux 65dac7c84719 4.15.0-213-generic #224-Ubuntu SMP Mon Jun 19 13:30:12 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux ******************************************************************************* gcc version: Using built-in specs. COLLECT_GCC=/home/software/gcc-trunk-3aa004f/bin/gcc COLLECT_LTO_WRAPPER=/home/software/gcc-trunk-3aa004f/libexec/gcc/x86_64-pc-linux-gnu/15.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc/configure --disable-multilib --disable-bootstrap --enable-languages=c,c++ --prefix=/home/software/gcc-trunk-3aa004f --enable-coverage Thread model: posix Supported LTO compression algorithms: zlib gcc version 15.0.0 20240630 (experimental) (GCC) ******************************************************************************* Program: $ cat mutant.c struct a { int b; } c(); void __attribute__((returns_twice)) bar() { struct a d; { bar(d); c(d.b, d.b); } } ******************************************************************************* Command Lines: $ gcc -O1 mutant.c mutant.c: In function 'bar': mutant.c:10:1: error: returns_twice call is not first in basic block 2 10 | } | ^ bar (d); during GIMPLE pass: esra mutant.c:10:1: internal compiler error: verify_flow_info failed 0x5071bcf diagnostic_context::report_diagnostic(diagnostic_info*) ???:0 0x50724a1 diagnostic_context::diagnostic_impl(rich_location*, diagnostic_metadata const*, int, char const*, __va_list_tag (*) [1], diagnostic_t) ???:0 0x50924c7 internal_error(char const*, ...) ???:0 0x11b395c verify_flow_info() ???: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. It can be compiled normally with -O0. Also ICE on trunk. Compiler Explorer: https://godbolt.org/z/c3YGen7hb