host/include/generic/host/atomic128: Fix compilation problem with Clang 17

When compiling QEMU with Clang 17 on a s390x, the compilation fails:

In file included from ../accel/tcg/cputlb.c:32:
In fi

host/include/generic/host/atomic128: Fix compilation problem with Clang 17

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>

show more ...

host/include/generic/host/atomic128: Fix compilation problem with Clang 17

When compiling QEMU with Clang 17 on a s390x, the compilation fails:

In file included from ../accel/tcg/cputlb.c:32:
In fi

host/include/generic/host/atomic128: Fix compilation problem with Clang 17

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>

show more ...

meson: Split test for __int128_t type from __int128_t arithmetic

Older versions of clang have missing runtime functions for arithmetic
with -fsanitize=undefined (see 464e3671f9d5c), so we cannot use

meson: Split test for __int128_t type from __int128_t arithmetic

Older versions of clang have missing runtime functions for arithmetic
with -fsanitize=undefined (see 464e3671f9d5c), 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>

show more ...

meson: Split test for __int128_t type from __int128_t arithmetic

Older versions of clang have missing runtime functions for arithmetic
with -fsanitize=undefined (see 464e3671f9d5c), so we cannot use

meson: Split test for __int128_t type from __int128_t arithmetic

Older versions of clang have missing runtime functions for arithmetic
with -fsanitize=undefined (see 464e3671f9d5c), 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>

show more ...

qemu/int128: Re-shuffle Int128Alias members

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

qemu/int128: Re-shuffle Int128Alias members

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>

show more ...

qemu/int128: Re-shuffle Int128Alias members

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

qemu/int128: Re-shuffle Int128Alias members

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>

show more ...

include/qemu/int128: Use Int128 structure for TCI

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 atomic

include/qemu/int128: Use Int128 structure for TCI

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>

show more ...

include/qemu/int128: Use Int128 structure for TCI

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 atomic

include/qemu/int128: Use Int128 structure for TCI

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>

show more ...

host-utils: Implemented unsigned 256-by-128 division

Based on already existing QEMU implementation, created an unsigned 256
bit by 128 bit division needed to implement the vector divide extended
uns

host-utils: Implemented unsigned 256-by-128 division

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>

show more ...

host-utils: Implemented unsigned 256-by-128 division

Based on already existing QEMU implementation, created an unsigned 256
bit by 128 bit division needed to implement the vector divide extended
uns

host-utils: Implemented unsigned 256-by-128 division

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>

show more ...

host-utils: Implemented unsigned 256-by-128 division

Based on already existing QEMU implementation, created an unsigned 256
bit by 128 bit division needed to implement the vector divide extended
uns

host-utils: Implemented unsigned 256-by-128 division

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>

show more ...

softfloat: add float128_to_int128

Implements float128_to_int128 based on parts_float_to_int logic.

Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Richard Henderson <richa

softfloat: add float128_to_int128

Implements float128_to_int128 based on parts_float_to_int logic.

Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220330175932.6995-7-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

show more ...

qemu/int128: add int128_urshift

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@eldor

qemu/int128: add int128_urshift

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>

show more ...

Replace config-time define HOST_WORDS_BIGENDIAN

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 avoid

Replace config-time define HOST_WORDS_BIGENDIAN

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>

show more ...

qemu/int128: addition of div/rem 128-bit operations

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 di

qemu/int128: addition of div/rem 128-bit operations

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>

show more ...

qemu/int128: Add int128_{not,xor}

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@g

qemu/int128: Add int128_{not,xor}

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>

show more ...

include/qemu/int128.h: introduce bswap128s

Changes the current bswap128 implementation to use __builtin_bswap128
when available, adds a bswap128 implementation for !CONFIG_INT128
builds, and introdu

include/qemu/int128.h: introduce bswap128s

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>

show more ...

include/qemu/int128.h: define struct Int128 according to the host endianness

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by:

include/qemu/int128.h: define struct Int128 according to the host endianness

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20210826141446.2488609-2-matheus.ferst@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

show more ...

include/qemu/int128.h: Add function to create Int128 from int64_t

int128_make64() creates an Int128 from an unsigned 64 bit value; add
a function int128_makes64() creating an Int128 from a signed 64

include/qemu/int128.h: Add function to create Int128 from int64_t

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

show more ...

qemu/int128: Add int128_or

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>
R

qemu/int128: Add int128_or

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>

show more ...

qemu/int128: Add int128_lshift

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

qemu/int128: Add int128_lshift

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>

show more ...

tcg: Add atomic128 helpers

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

tcg: Add atomic128 helpers

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>

show more ...

int128: Add int128_make128

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 Ben

int128: Add int128_make128

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>

show more ...

int128: Use __int128 if available

Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

exec: Avoid direct references to Int128 parts

Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>