This reverts commit 4ac7691073.
This fixes
http://lists.nongnu.org/archive/html/qemu-devel/2017-01/msg03062.html
While I think we could get away with relying on the undocumented
behaviour, the tcg constraint system isn't powerful enough to
properly describe the required (non-)overlap conditions.
Reported-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The number of actual invocations of ctpop itself does not warrent
an opcode, but it is very helpful for POWER7 to use in generating
an expansion for ctz.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The ISA manual documents the output is undefined if the input was zero.
However, we document in target-i386 that the behavior of real silicon
is to preserve the contents of the output register. We also mention
that there are real applications that depend on this. That this is
baked into silicon is mentioned as a potential cause for some false
sharing behaviour wrt lzcnt/tzcnt.
Taking advantage of this allows us to save 2 insns in the normal case,
and 4 insns for i686 emulating a 64-bit clz.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Previously we could not have different constraints for different ISA levels,
which prevented us from eliding the matching constraint for shifts.
We do now have to make sure that the operands match for constant shifts.
We can also handle some small left shifts via lea.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Use a switch instead of searching a table. Share constraints between
32-bit and 64-bit, when at all possible.
Signed-off-by: Richard Henderson <rth@twiddle.net>
This will let us choose how to interpret a given constraint
depending on whether the opcode is 32- or 64-bit. Which will
let us share more constraint combinations between opcodes.
At the same time, change the interface to return the advanced
pointer instead of passing it in/out by reference.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This will allow the target to tailor the constraints to the
auto-detected ISA extensions.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Adds tcg_gen_extract_* and tcg_gen_sextract_* for extraction of
fixed position bitfields, much like we already have for deposit.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
TARGET_PAGE_MASK, as defined, has type "int". We need to extend
that to the proper target width before oring in an "unsigned".
Signed-off-by: Richard Henderson <rth@twiddle.net>
Generate a 'lock orl $0,0(%esp)' instruction for ordering instead of
mfence which has similar ordering semantics.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <20160714202026.9727-3-bobby.prani@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Previously we allowed fully unaligned operations, but not operations
that are aligned but with less alignment than the operation size.
In addition, arm32, ia64, mips, and sparc had been omitted from the
previous overalignment patch, which would have led to that alignment
being enforced.
Signed-off-by: Richard Henderson <rth@twiddle.net>
These use guard symbols like TCG_TARGET_$target.
scripts/clean-header-guards.pl doesn't like them because they don't
match their file name (they should, to make guard collisions less
likely).
Clean them up: use guard symbol $target_TCG_TARGET_H for
tcg/$target/tcg-target.h.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Some architectures (e.g. ARMv8) need the address which is aligned
to a size more than the size of the memory access.
To support such check it's enough the current costless alignment
check implementation in QEMU, but we need to support
an alignment size specifying.
Signed-off-by: Sergey Sorokin <afarallax@yandex.ru>
Message-Id: <1466705806-679898-1-git-send-email-afarallax@yandex.ru>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Assert in tcg_canonicalize_memop. Leave get_alignment_bits
available for, though unused by, user-mode. Retain logging difference
based on ALIGNED_ONLY.]
While we can store constants via constrants on INDEX_op_st_i32 et al,
we weren't able to spill constants to backing store.
Add a new backend interface, tcg_out_sti, which may store the constant
(and is allowed to fail). Rearrange the temp_* helpers so that we only
attempt to directly store a constant when the temp is becoming dead/free.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Briefly describe in a comment how direct block chaining is done. It
should help in understanding of the following data fields.
Rename some fields in TranslationBlock and TCGContext structures to
better reflect their purpose (dropping excessive 'tb_' prefix in
TranslationBlock but keeping it in TCGContext):
tb_next_offset => jmp_reset_offset
tb_jmp_offset => jmp_insn_offset
tb_next => jmp_target_addr
jmp_next => jmp_list_next
jmp_first => jmp_list_first
Avoid using a magic constant as an invalid offset which is used to
indicate that there's no n-th jump generated.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Ensure direct jump patching in i386 is atomic by:
* naturally aligning a location of direct jump address;
* using atomic_read()/atomic_set() for code patching.
tcg_out_nopn() implementation:
Suggested-by: Richard Henderson <rth@twiddle.net>.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-6-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Check for CONFIG_DEBUG_TCG instead of NDEBUG, drop now useless code.
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-id: 1461228530-14852-2-git-send-email-aurelien@aurel32.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The TCG code is quite performance sensitive, but at the same time can
also be quite tricky. That is why asserts that can be enabled with the
--enable-debug-tcg configure option.
This used to work the following way:
| #include "config.h"
|
| ...
|
| #if !defined(CONFIG_DEBUG_TCG) && !defined(NDEBUG)
| /* define it to suppress various consistency checks (faster) */
| #define NDEBUG
| #endif
|
| ...
|
| #include <assert.h>
Since commit 757e725b (tcg: Clean up includes) "config.h" as been
replaced by "qemu/osdep.h" which itself includes <assert.h>. As a
consequence the assertions are always enabled, even when using
--disable-debug-tcg, causing a performance regression, especially on
targets with many registers. For instance on qemu-system-ppc the
speed difference is about 15%.
tcg_debug_assert is controlled directly by CONFIG_DEBUG_TCG and already
uses in some places. This patch replaces all the calls to assert into
calss to tcg_debug_assert.
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-id: 1461228530-14852-1-git-send-email-aurelien@aurel32.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Commit 757e725b58 added a number of #include "qemu/osdep.h"
files to the tcg-target.c files (as they were named at the time).
These are unnecessary because these files are not standalone C
files, and the tcg/tcg.c file which includes them will have
already included osdep.h on their behalf. Remove the unneeded
include directives.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1456238983-10160-4-git-send-email-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Rename the per-architecture tcg-target.c files to tcg-target.inc.c.
This makes it clearer that they are not intended to be standalone
C files, but are instead #included into another source file.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1456238983-10160-2-git-send-email-peter.maydell@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.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-16-git-send-email-peter.maydell@linaro.org
When computing the TLB address we are likely to mask out the high
32-bits by using shr + and. We can use 32-bit instructions in that
case. This saves 2 bytes per TLB access.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <1437306632-20655-1-git-send-email-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
As we have removed CONFIG_USE_GUEST_BASE, we always use a guest base
and the macros GUEST_BASE and RESERVED_VA become useless: replace
them by their values.
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1440420834-8388-1-git-send-email-laurent@vivier.eu>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Softmmu unaligned load/stores currently goes through through the slow
path for two reasons:
- to support unaligned access on host with strict alignement
- to correctly handle accesses crossing pages
x86 is only concerned by the second reason. Unaligned accesses are
avoided by compilers, but are not uncommon. We therefore would like
to see them going through the fast path, if they don't cross pages.
For that we can use the fact that two adjacent TLB entries can't contain
the same page. Therefore accessing the TLB entry corresponding to the
first byte, but comparing its content to page address of the last byte
ensures that we don't cross pages. We can do this check without adding
more instructions in the TLB code (but increasing its length by one
byte) by using the LEA instruction to combine the existing move with the
size addition.
On an x86-64 host, this gives a 3% boot time improvement for a powerpc
guest and 4% for an x86-64 guest.
[rth: Tidied calculation of the offset mask]
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <1436467197-2183-1-git-send-email-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Rather than allow arbitrary shift+trunc, only concern ourselves
with low and high parts. This is all that was being used anyway.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Implement real ext_i32_i64 and extu_i32_i64 ops. They ensure that a
32-bit value is always converted to a 64-bit value and not propagated
through the register allocator or the optimizer.
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Stefan Weil <sw@weilnetz.de>
Acked-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The op is sometimes named trunc_shr_i32 and sometimes trunc_shr_i64_i32,
and the name in the README doesn't match the name offered to the
frontends.
Always use the long name to make it clear it is a size changing op.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The addition of MO_AMASK means that places that used inverted masks
need to be changed to use positive masks, and places that failed to
mask the intended bits need updating.
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Tested-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This will be used to size the TLB when more than 8 MMU modes are
used by the target. Limitations come from the limited size of
the immediate fields (which sometimes, as in the case of Aarch64,
extend to instructions that shift the immediate).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1424436345-37924-2-git-send-email-pbonzini@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Alexander Graf <agraf@suse.de>
The extra information is not yet used but it is now available.
This requires minor changes through all of the tcg backends.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
At the tcg opcode level, not at the tcg-op.h generator level.
This requires minor changes through all of the tcg backends,
but none of the cpu translators.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This is less about improved type checking than enabling a
subsequent change to the representation of labels.
Acked-by: Claudio Fontana <claudio.fontana@huawei.com>
Tested-by: Claudio Fontana <claudio.fontana@huawei.com>
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This is improved type checking for the translators -- it's no longer
possible to accidentally swap arguments to the branch functions.
Note that the code generating backends still manipulate labels as int.
With notable exceptions, the scope of the change is just a few lines
for each target, so it's not worth building extra machinery to do this
change in per-target increments.
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Anthony Green <green@moxielogic.com>
Cc: Jia Liu <proljc@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Since all backends have been converted, remove the compatibility code.
Acked-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The first non-register argument isn't placed at offset 0.
Cc: qemu-stable@nongnu.org
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The INDEX_op_call case has just been obsoleted; the mov and movi
cases have not been reachable for years. Attempt to document this
both in each tcg_out_op switch, and via TCG_OPF_NOT_PRESENT.
Because of the TCG_OPF_NOT_PRESENT change, this must be done for
all targets in a single commit.
Signed-off-by: Richard Henderson <rth@twiddle.net>
And use tcg pointer differencing functions as appropriate.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
To avoid C undefined behaviour when patching generated code,
provide wrappers tcg_patch8/16/32/64 which use the usual memcpy
trick, and use them in the i386 backend.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Most 64-bit targets need to be able to ignore the high bits
of a TCG_TYPE_I32 value.
Suggested-by: Stuart Brady <sdb@zubnet.me.uk>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Richard Henderson
Pranith Kumar
Markus Armbruster
Sergey Sorokin
Sergey Fedorov
Aurelien Jarno
Peter Maydell
Laurent Vivier
Paolo Bonzini