https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93213
Bug ID: 93213
Summary: [10 Regression] wrong code with -Og -foptimize-strlen
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Created attachment 47620
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47620&action=edit
reduced testcase
Output:
$ x86_64-pc-linux-gnu-gcc -Og -foptimize-strlen testcase.c
$ ./a.out
Aborted
At the assembly level:
...
mov WORD PTR [rsp+14], -1 # u16_1,
# testcase.c:11: __builtin_memmove (&u16_1, &u128_1, 1);
mov BYTE PTR [rsp+14], -1 # MEM[(char * {ref-all})&u16_1],
...
the first memove (which woudl set u16_1 = 0) is removed
Might be related to PR92765 and PR92956.
Still observed at r280046
$ 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-280046-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.0.0/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 --with-cloog --with-ppl --with-isl
--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 --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-280046-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.0.0 20200109 (experimental) (GCC)
