target/riscv/vector_helpers: do early exit when vstart >= vl

We're going to make changes that will required each helper to be
responsible for the 'vstart' management, i.e. we will relieve the
'vstar

target/riscv/vector_helpers: do early exit when vstart >= vl

We're going to make changes that will required each helper to be
responsible for the 'vstart' management, i.e. we will relieve the
'vstart < vl' assumption that helpers have today.

Helpers are usually able to deal with vstart >= vl, i.e. doing nothing
aside from setting vstart = 0 at the end, but the tail update functions
will update the tail regardless of vstart being valid or not. Unifying
the tail update process in a single function that would handle the
vstart >= vl case isn't trivial (see [1] for more info).

This patch takes a blunt approach: do an early exit in every single
vector helper if vstart >= vl, unless the helper is guarded with
vstart_eq_zero in the translation. For those cases the helper is ready
to deal with cases where vl might be zero, i.e. throwing exceptions
based on it like vcpop_m() and first_m().

Helpers that weren't changed:

- vcpop_m(), vfirst_m(), vmsetm(), GEN_VEXT_VIOTA_M(): these are guarded
directly with vstart_eq_zero;

- GEN_VEXT_VCOMPRESS_VM(): guarded with vcompress_vm_check() that checks
vstart_eq_zero;

- GEN_VEXT_RED(): guarded with either reduction_check() or
reduction_widen_check(), both check vstart_eq_zero;

- GEN_VEXT_FRED(): guarded with either freduction_check() or
freduction_widen_check(), both check vstart_eq_zero.

Another exception is vext_ldst_whole(), who operates on effective vector
length regardless of the current settings in vtype and vl.

[1] https://lore.kernel.org/qemu-riscv/1590234b-0291-432a-a0fa-c5a6876097bc@linux.alibaba.com/

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240314175704.478276-7-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

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riscv: Clean up includes

This commit was created with scripts/clean-includes:
./scripts/clean-includes --git riscv target/riscv/*.[ch]

All .c should include qemu/osdep.h first. The script perform

riscv: Clean up includes

This commit was created with scripts/clean-includes:
./scripts/clean-includes --git riscv target/riscv/*.[ch]

All .c should include qemu/osdep.h first. The script performs three
related cleanups:

* Ensure .c files include qemu/osdep.h first.
* Including it in a .h is redundant, since the .c already includes
it. Drop such inclusions.
* Likewise, including headers qemu/osdep.h includes is redundant.
Drop these, too.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

show more ...

riscv: Clean up includes

This commit was created with scripts/clean-includes:
./scripts/clean-includes --git riscv target/riscv/*.[ch]

All .c should include qemu/osdep.h first. The script perform

riscv: Clean up includes

This commit was created with scripts/clean-includes:
./scripts/clean-includes --git riscv target/riscv/*.[ch]

All .c should include qemu/osdep.h first. The script performs three
related cleanups:

* Ensure .c files include qemu/osdep.h first.
* Including it in a .h is redundant, since the .c already includes
it. Drop such inclusions.
* Likewise, including headers qemu/osdep.h includes is redundant.
Drop these, too.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

show more ...

target/riscv: Refactor some of the generic vector functionality

Move some macros out of `vector_helper` and into `vector_internals`.
This ensures they can be used by both vector and vector-crypto he

target/riscv: Refactor some of the generic vector functionality

Move some macros out of `vector_helper` and into `vector_internals`.
This ensures they can be used by both vector and vector-crypto helpers
(latter implemented in proceeding commits).

Signed-off-by: Kiran Ostrolenk <kiran.ostrolenk@codethink.co.uk>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Max Chou <max.chou@sifive.com>
Message-ID: <20230711165917.2629866-8-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Refactor some of the generic vector functionality

Take some functions/macros out of `vector_helper` and put them in a new
module called `vector_internals`. This ensures they can be use

target/riscv: Refactor some of the generic vector functionality

Take some functions/macros out of `vector_helper` and put them in a new
module called `vector_internals`. This ensures they can be used by both
vector and vector-crypto helpers (latter implemented in proceeding
commits).

Signed-off-by: Kiran Ostrolenk <kiran.ostrolenk@codethink.co.uk>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Max Chou <max.chou@sifive.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230711165917.2629866-2-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Refactor some of the generic vector functionality

Move some macros out of `vector_helper` and into `vector_internals`.
This ensures they can be used by both vector and vector-crypto he

target/riscv: Refactor some of the generic vector functionality

Move some macros out of `vector_helper` and into `vector_internals`.
This ensures they can be used by both vector and vector-crypto helpers
(latter implemented in proceeding commits).

Signed-off-by: Kiran Ostrolenk <kiran.ostrolenk@codethink.co.uk>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Max Chou <max.chou@sifive.com>
Message-ID: <20230711165917.2629866-8-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Refactor some of the generic vector functionality

Take some functions/macros out of `vector_helper` and put them in a new
module called `vector_internals`. This ensures they can be use

target/riscv: Refactor some of the generic vector functionality

Take some functions/macros out of `vector_helper` and put them in a new
module called `vector_internals`. This ensures they can be used by both
vector and vector-crypto helpers (latter implemented in proceeding
commits).

Signed-off-by: Kiran Ostrolenk <kiran.ostrolenk@codethink.co.uk>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Max Chou <max.chou@sifive.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230711165917.2629866-2-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...