https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93402
Bug ID: 93402
Summary: Wrong code when returning padded struct
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: v at hnn dot net.br
Target Milestone: ---
Target: x86_64-pc-linux-gnu
Created attachment 47698
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47698&action=edit
Minimal example
Output:
$ gcc example.c -O3 -fno-inline
$ ./a.out
a.out: example.c:23: main: Assertion `output.b == 122222222222' failed.
Abortado (imagem do núcleo gravada)
The assembly output:
```
fn:
movabs rdx, 11111111111
xor eax, eax
imul rdi, rdx
movabs rdx, 111111111111
ret
```
Always returns ret.a = 0 and ret.b = 111111111111
This seems to be a GCC 6 regression [1]
Many thanks to everyone on StackOverflow who helped me with this [2]
[1]: "https://gcc.godbolt.org/z/le3EYP";
[2]:
"https://stackoverflow.com/questions/59871171/possible-gcc-bug-when-returning-struct-from-a-function";
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
