Fix some of the nasty TCG race conditions and crashes by implementing
cpu_exit() as setting a flag which is checked at the start of each TB.
This avoids crashes if a thread or signal handler calls cpu_exit()
while the execution thread is itself modifying the TB graph (which
may happen in system emulation mode as well as in linux-user mode
with a multithreaded guest binary).
This fixes the crashes seen in LP:668799; however there are another
class of crashes described in LP:1098729 which stem from the fact
that in linux-user with a multithreaded guest all threads will
use and modify the same global TCG date structures (including the
generated code buffer) without any kind of locking. This means that
multithreaded guest binaries are still in the "unsupported"
category.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Document tcg_qemu_tb_exec(). In particular, its return value is a
combination of a pointer to the next translation block and some
extra information in the low two bits. Provide some #defines for
the values passed in these bits to improve code clarity.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
It's worth to clean-up translation blocks variables and move them
into one context as was suggested by Swirl.
Also if we use this context directly inside tcg_ctx, then it
speeds up code generation a bit.
Signed-off-by: Evgeny Voevodin <evgenyvoevodin@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Add optimized TCG qemu_ld/st generation which locates the code of TLB miss
cases at the end of a block after generating the other IRs.
Currently, this optimization supports only i386 and x86_64 hosts.
Signed-off-by: Yeongkyoon Lee <yeongkyoon.lee@samsung.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The current helper flags, TCG_CALL_CONST and TCG_CALL_PURE might be
confusing and doesn't provide enough granularity for some helpers (FP
helpers for example).
This patch changes them into the following helpers flags:
- TCG_CALL_NO_READ_GLOBALS means that the helper does not read globals,
either directly or via an exception. They will not be saved to their
canonical location before calling the helper.
- TCG_CALL_NO_WRITE_GLOBALS means that the helper does not modify any
globals. They will only be saved to their canonical locations before
calling helpers, but they won't be reloaded afterwise.
- TCG_CALL_NO_SIDE_EFFECTS means that the call to the function is
removed if the return value is not used.
It provides convenience flags, to avoid helper definitions longer than
80 characters. It also provides compatibility flags, and updates the
documentation.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Operations with side effects (in practice qemu_ld/st ops), only need to
synchronize globals to make sure the CPU state is consistent in case of
exception.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Synchronize an output argument when requested by the liveness analysis.
This is needed so that the temp can be declared dead later.
For that, add a new op_sync_args table in which each bit tells if the
corresponding output argument needs to be synchronized with the memory.
Pass it to the tcg_reg_alloc_* functions, and honor this bit. We need to
synchronize the argument before marking it as dead, and we have to make
sure all the infos about the temp are correctly filled.
At the same time change some types from unsigned int to uint16_t when
passing op_dead_args.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We had a hack for arm and sparc, allocating code_gen_prologue to a
special section. Which, honestly does no good under certain cases.
We've already got limits on code_gen_buffer_size to ensure that all
TBs can use direct branches between themselves; reuse this limit to
ensure the prologue is also reachable.
As a bonus, we get to avoid marking a page of the main executable's
data segment as executable.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The pointer entry 'temps' always refers to the array entry 'static_temps'.
Removing the pointer and renaming 'static_temps' to 'temps' reduces the
size of TCGContext (4 or 8 byte) and allows better code generation.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The table that was recently added for hppa is generally usable.
And with the renumbering of the TCG_COND constants it's not too
difficult to compute rather than have a table.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
There are several cases that can be handled easier inside both
translators and code generators if we have out-of-band values
for conditions. It's easy enough to handle ALWAYS and NEVER in
the natural way inside the tcg middle-end.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Before we rearrange the TCG_COND enumeration, add a predicate for
the (single) use of comparisons vs TCGCond.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Checking that we don't try for idx != [01] is trivial. Checking
that we don't issue more than one of any index requires a tad
more data and some ifdefs protecting that new variable.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Like the C assert macro, except only enabled for CONFIG_DEBUG_TCG,
and without having to set _NDEBUG and disable all other asserts at
the same time.
The use of __builtin_unreachable (when available) gives the compiler
the same information, which may (or may not) help it optimize better.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Commit 6375e09e changed the type of TranslationBlock.tb_next,
but failed to change the type of TCGContext.tb_next.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Implemented with setcond if the target does not provide
the optional opcode.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Given the copy propagation breakage on 32-bit hosts has been fixed
commit e31b0a7c05 can be reverted.
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Now that there are two passes of optimization (optimize.c, liveness)
there is no point of outputing the statistics of the liveness part
only. Update the code to take into account both optimizations.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Don't use global variables directly but via accessor functions. Rename globals.
Convert macros to functions, add GCC format attributes.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This allows us to generate unwind info for the dynamicly generated
code in the code_gen_buffer. Only i386 is converted at this point.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Use stack based calling convention (GCC default) for interfacing with
generated code instead of register based convention (regparm(3)).
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
next_tb is the numeric value of a tcg target (= QEMU host) address.
Using tcg_target_ulong instead of unsigned long shows this and makes
the code portable for hosts with an unusual size of long (w64).
The type cast '(long)(next_tb & ~3)' was not needed (casting
unsigned long to long does not change the bits, and nor does
casting long to pointer for most (= all non w64) hosts.
It is removed here.
Macro or function tcg_qemu_tb_exec is used to set next_tb.
The function also returns next_tb. Therefore tcg_qemu_tb_exec
must return a tcg_target_ulong.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
An attempt to allocate a large memory chunk after a small one resulted in
circular links in list of pools. It caused the same memory being
allocated twice for different arrays.
Now pools for large memory chunks are kept in separate list and are
freed during pool reset because current allocator can not reuse them.
Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This change makes tcg_target_ulong available in tcg-target.h.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Make tcg_const_ptr() include a cast so that you can pass it a
pointer. This allows us to drop the casts we had in all the places
that use this macro.
Acked-by: Andreas Färber <andreas.faerber@web.de>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
tcg_op_defs was already a global array.
The tci disassembler also needs ARRAY_SIZE(tcg_op_defs),
so add a new global constant with this value.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Targets may use a non standard definition of tcg_tb_exec
by defining this macro in their tcg_target.h.
This is used here by ppc. It will be used by the TCG interpreter, too.
Cc: malc <av1474@comtv.ru>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
x86 cannot provide an optimized generic deposit implementation. But at
least for a few special cases, namely for writing bits 0..7, 8..15, and
0..15, versions using only a single instruction are feasible.
Introducing such limited support improves emulating 16-bit x86 code on
x86, but also rarer cases where 32-bit or 64-bit code accesses bytes or
words.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
TCG_TARGET_REG_BITS can be determined by the compiler,
so there is no need to declare it for each individual tcg target.
This is especially important for new tcg targets
which will be supported by the tcg interpreter.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
By always defining these symbols, we can eliminate a lot of ifdefs.
To allow this to be checked reliably, the semantics of the
TCG_TARGET_HAS_* macros must be changed from def/undef to true/false.
This allows even more ifdefs to be removed, converting them into
C if statements.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This allows the simplification of the op_bits function from
tcg/optimize.c.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Copy propagation introduced in 22613af4a6
considered only global registers. However, register temps and stack
allocated locals must be handled differently because register temps
don't survive across brcond.
Fix by propagating only within same class of temps.
Tested-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Added file tcg/optimize.c to hold TCG optimizations. Function tcg_optimize
is called from tcg_gen_code_common. It calls other functions performing
specific optimizations. Stub for constant folding was added.
Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Make functions take a parameter for CPUState instead of relying
on global env. Pass CPUState pointer to TCG prologue, which moves
it to AREG0.
Thanks to Peter Maydell and Laurent Desnogues for the ARM prologue
change.
Revert the hacks to avoid AREG0 use on Sparc hosts.
Move cpu_has_work() and cpu_pc_from_tb() from exec.h to cpu.h.
Compile the file without HELPER_CFLAGS.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
When compiling with DEBUG_TCGV enabled, make the TCGv_ptr type distinct
from TCGv_i32/TCGv_i64. This means that using an i32 or i64 TCG op to
manipulate a TCGv_ptr will always be detected at compile time, rather
than only if compiling on a host system with the other word size.
NB: the tcg_add_ptr and tcg_sub_ptr macros have been removed as they
were not used anywhere.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Allow all args to be dead by replacing the input specific op_dead_iargs
variable by op_dead_args. Note this is a purely mechanical change.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
