https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123925
Bug ID: 123925
Summary: [16 Regression] wrong code with -march=rv64gv due to
missing sign extension at -O1
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: riscv64-unknown-linux-gnu
Created attachment 63556
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63556&action=edit
reduced testcase
Output:
$ riscv64-unknown-linux-gnu-gcc -O -march=rv64gv testcase.c -static
$ qemu-riscv64 -- ./a.out
Aborted qemu-riscv64 -- ./a.out
This is using qemu userspace emulation; it might be also an issue in the
emulation itself, or its configuration.
The result is 0xf8 instead of 64bit -8.
$ riscv64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-riscv64/bin/riscv64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-20260202100715-r16-7239-g49c7fc2d534cb7-checking-yes-rtl-df-extra-riscv64/bin/../libexec/gcc/riscv64-unknown-linux-gnu/16.0.1/lto-wrapper
Target: riscv64-unknown-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--enable-libsanitizer --with-isa-spec=2.2
--with-sysroot=/usr/riscv64-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=riscv64-unknown-linux-gnu
--with-ld=/usr/bin/riscv64-unknown-linux-gnu-ld
--with-as=/usr/bin/riscv64-unknown-linux-gnu-as --disable-multilib
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-20260202100715-r16-7239-g49c7fc2d534cb7-checking-yes-rtl-df-extra-riscv64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.1 20260202 (experimental) (GCC)
