When compiling QEMU with Clang 17 on a s390x, the compilation fails:
In file included from ../accel/tcg/cputlb.c:32:
In file included from /root/qemu/include/exec/helper-proto-common.h:10:
In file included from /root/qemu/include/qemu/atomic128.h:62:
/root/qemu/host/include/generic/host/atomic128-ldst.h:68:15: error:
__sync builtin operation MUST have natural alignment (consider using __
atomic). [-Werror,-Wsync-alignment]
68 | } while (!__sync_bool_compare_and_swap_16(ptr_align, old, new.i));
| ^
In file included from ../accel/tcg/cputlb.c:32:
In file included from /root/qemu/include/exec/helper-proto-common.h:10:
In file included from /root/qemu/include/qemu/atomic128.h:61:
/root/qemu/host/include/generic/host/atomic128-cas.h:36:11: error:
__sync builtin operation MUST have natural alignment (consider using __a
tomic). [-Werror,-Wsync-alignment]
36 | r.i = __sync_val_compare_and_swap_16(ptr_align, c.i, n.i);
| ^
2 errors generated.
It's arguably a bug in Clang since we already use __builtin_assume_aligned()
to tell the compiler that the pointer is properly aligned. But according to
https://github.com/llvm/llvm-project/issues/69146 it seems like the Clang
folks don't see an easy fix on their side and recommend to use a type
declared with __attribute__((aligned(16))) to work around this problem.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1934
Message-ID: <20231108085954.313071-1-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Older versions of clang have missing runtime functions for arithmetic
with -fsanitize=undefined (see 464e3671f9), so we cannot use
__int128_t for implementing Int128. But __int128_t is present,
data movement works, and it can be used for atomic128.
Probe for both CONFIG_INT128_TYPE and CONFIG_INT128, adjust
qemu/int128.h to define Int128Alias if CONFIG_INT128_TYPE,
and adjust the meson probe for atomics to use has_int128_type.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Clang 14, with --enable-tcg-interpreter errors with
include/qemu/int128.h:487:16: error: alignment of field 'i' (128 bits)
does not match the alignment of the first field in transparent union;
transparent_union attribute ignored [-Werror,-Wignored-attributes]
__int128_t i;
^
include/qemu/int128.h:486:12: note: alignment of first field is 64 bits
Int128 s;
^
1 error generated.
By placing the __uint128_t member first, this is avoided.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230501204625.277361-1-richard.henderson@linaro.org>
We are about to allow passing Int128 to/from tcg helper functions,
but libffi doesn't support __int128_t, so use the structure.
In order for atomic128.h to continue working, we must provide
a mechanism to frob between real __int128_t and the structure.
Provide a new union, Int128Alias, for this. We cannot modify
Int128 itself, as any changed alignment would also break libffi.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Based on already existing QEMU implementation, created an unsigned 256
bit by 128 bit division needed to implement the vector divide extended
unsigned instruction from PowerISA3.1
Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220525134954.85056-5-lucas.araujo@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Implement an unsigned right shift for Int128 values and add the same
tests cases of int128_rshift in the unit test.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220330175932.6995-3-matheus.ferst@eldorado.org.br>
[danielhb: fixed long lines in test_urshift()]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.
This can help to make some code independent from qemu too.
gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Addition of div and rem on 128-bit integers, using the 128/64->128 divu and
64x64->128 mulu in host-utils.
These operations will be used within div/rem helpers in the 128-bit riscv
target.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-4-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Addition of not and xor on 128-bit integers.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Message-Id: <20211025122818.168890-3-frederic.petrot@univ-grenoble-alpes.fr>
[rth: Split out logical operations.]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Changes the current bswap128 implementation to use __builtin_bswap128
when available, adds a bswap128 implementation for !CONFIG_INT128
builds, and introduces bswap128s based on bswap128.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20210826145656.2507213-2-matheus.ferst@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
int128_make64() creates an Int128 from an unsigned 64 bit value; add
a function int128_makes64() creating an Int128 from a signed 64 bit
value.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210614151007.4545-34-peter.maydell@linaro.org
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201021045149.1582203-2-richard.henderson@linaro.org>
Add left-shift to match the existing right-shift.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200815013145.539409-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Force the use of cmpxchg16b on x86_64.
Wikipedia suggests that only very old AMD64 (circa 2004) did not have
this instruction. Further, it's required by Windows 8 so no new cpus
will ever omit it.
If we truely care about these, then we could check this at startup time
and then avoid executing paths that use it.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Allows Int128 to be used more generally, rather than having to
begin with 64-bit inputs and accumulate.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
NB: If this commit breaks compilation for your out-of-tree
patchseries or fork, then you need to make sure you add
#include "qemu/osdep.h" to any new .c files that you have.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
This adds macro to extend signed 64bit value to signed 128bit value.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add casts when we're performing arithmetic on the .hi parts of an
Int128, to avoid undefined behaviour.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
For add, the carry only requires checking one of the arguments.
For sub and neg, we can similarly optimize computation of the
carry.
For ge, we can just do lexicographic order.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
So far, the size of all regions passed to listeners could fit in 64 bits,
because artificial regions (containers and aliases) are eliminated by
the memory core, leaving only device regions which have reasonable sizes
An IOMMU however cannot be eliminated by the memory core, and may have
an artificial size, hence we may need 65 bits to represent its size.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
