https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121828
Bug ID: 121828
Summary: during GIMPLE pass: bitintlower ICE: definition in
block 2 follows the use with __builtin_sub_overflow()
and __builtin_memset()
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
CC: jakub at gcc dot gnu.org
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-pc-linux-gnu
Created attachment 62330
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62330&action=edit
reduced testcase
Compiler output:
$ x86_64-pc-linux-gnu-gcc -O testcase.c
testcase.c: In function 'foo':
testcase.c:7:1: error: definition in block 2 follows the use
7 | foo()
| ^~~
for SSA_NAME: _36 in statement:
_5 = _36;
during GIMPLE pass: bitintlower
testcase.c:7:1: internal compiler error: verify_ssa failed
0x2b9a34c internal_error(char const*, ...)
/repo/gcc-trunk/gcc/diagnostic-global-context.cc:786
0x18821d0 verify_ssa(bool, bool)
/repo/gcc-trunk/gcc/tree-ssa.cc:1203
0x1491384 execute_function_todo
/repo/gcc-trunk/gcc/passes.cc:2104
0x14917fe execute_todo
/repo/gcc-trunk/gcc/passes.cc:2149
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.
$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-20250906022034-r16-3610-g1179ac1fabf346-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --enable-libsanitizer
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-20250906022034-r16-3610-g1179ac1fabf346-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.0 20250906 (experimental) (GCC)
