Now that we have a do_illegal label, use goto in order
to self-document the forcing of the exception.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-22-rth@twiddle.net>
[aurel32: fix whitespace issues]
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We do not need to emit N copies of raising an exception.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-21-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We do not need to emit N copies of raising an exception.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-20-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We do not need to emit N copies of raising an exception.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-19-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We do not need to form full 64-bit quantities in order to perform
the move. This reduces code expansion on 64-bit hosts.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-18-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This enforces proper alignment and makes the register update
more natural. Note that there is a more serious bug fix for
fmov {DX}Rn,@(R0,Rn) to use a store instead of a load.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-17-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Also add a debugging assert that we did signal illegal opc
for odd double-precision registers.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-16-rth@twiddle.net>
[aurel32: fix whitespace issues]
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Compute which register bank to use once at the start of translation.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-14-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We were treating FREG as an index and REG as a TCGv.
Making FREG return a TCGv is both less confusing and
a step toward cleaner banking of cpu_fregs.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-12-rth@twiddle.net>
[aurel32: fix whitespace issues]
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Compute which register bank to use once at the start of translation.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-11-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
For many of the sequences produced by gcc or glibc,
we can translate these as host atomic operations.
Which saves the need to acquire the exclusive lock.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-8-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
For uniprocessors, SH4 uses optimistic restartable atomic sequences.
Upon an interrupt, a real kernel would simply notice magic values in
the registers and reset the PC to the start of the sequence.
For QEMU, we cannot do this in quite the same way. Instead, we notice
the normal start of such a sequence (mov #-x,r15), and start a new TB
that can be executed under cpu_exec_step_atomic.
Reported-by: Bruno Haible <bruno@clisp.org>
LP: https://bugs.launchpad.net/bugs/1701971
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-7-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Don't leave an unused bit after DELAY_SLOT_MASK.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-6-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
If we mask off any out-of-band bits before we assign to the
variable, then we don't need to clean it up when reading.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-5-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We'll be putting more things into this bitmask soon.
Let's have a name that covers all possible uses.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-4-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We can fold 3 different tests within the decode loop
into a more accurate computation of max_insns to start.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-3-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Since that the T bit of the SR register is mapped using a TGC global,
it's better to return the value through TCG than writing it directly. It
allows to declare the helpers with the flag TCG_CALL_NO_WG.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170702202814.27793-5-aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
There is no need to use a helper to flip one bit, just use a TCG xor
instruction instead.
Message-Id: <20170702202814.27793-5-aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The floating-point status/control register contains cause and flag
bits. The cause bits are set to 0 before executing the instruction,
while the flag bits hold the status of the exception generated after
the field was last cleared.
Message-Id: <20170702202814.27793-4-aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
In case of unordered compare, the fcmp instructions should either
trigger and invalid exception (if enabled) or set T=0. The existing code
left it unchanged.
LP: https://bugs.launchpad.net/qemu/+bug/1701821
Reported-by: Bruno Haible <bruno@clisp.org>
Message-Id: <20170702202814.27793-3-aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The SH4 manual is not fully clear about that, but real hardware do not
check for the PR bit, which allows to select between single or double
precision, for the fabs instruction. This is probably what is meant by
"Same operation is performed regardless of precision."
Remove the check, and at the same time use a TCG instruction instead of
a helper to clear one bit.
LP: https://bugs.launchpad.net/qemu/+bug/1701821
Reported-by: Bruno Haible <bruno@clisp.org>
Message-Id: <20170702202814.27793-2-aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The ReTurn from Exception (RTE) instruction loads the system register
(SR) with the saved system register (SSR). It has a delay slot, and
behaves specially according to the SH4 manual:
The SR value accessed by the instruction in the RTE delay slot is the
value restored from SSR by the RTE instruction. The SR and MD values
defined prior to RTE execution are used to fetch the instruction in
the RTE delay slot.
The instruction in the delay slot being often a NOP, it doesn't cause
any issue most of the time except in some rare cases where the NOP is
being splitted in a different TB (for example when the TCG op buffer
is full). In that case the NOP is fetched with the user permissions
and causes an instruction TLB protection violation exception.
This patches fixes that by introducing a new delay slot flag for the
RTE instruction. Given it's a privileged instruction, the RTE delay
slot instruction is always fetched in privileged mode. It is therefore
enough to to check for this flag in cpu_mmu_index.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Delay slots are indivisible, therefore avoid scheduling an interrupt in
the delay slot. However exceptions are possible.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This will make easier the introduction of a new flag in the next
patches.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
When a masked exception happens, the SH4 CPU generates a non-masked
reset exception, which then jumps to the reset vector at address
0xA0000000. While this is emulated correctly in QEMU, this does not
work when using a kernel and initrd as this address then contain an
illegal instruction (and there is no guarantee the kernel and initrd
haven't been overwritten).
Therefore call qemu_system_reset_request to reload the kernel and initrd
and load the program counter to the kernel entry point.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
qemu_log_mask() is preferred over fprintf() for logging errors.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Use cpu_loop_exit_restore when using cpu_restore_state and cpu_loop_exit
together.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
SH4 requires that memory accesses are naturally aligned, except for the
SH4-A movua.l instructions which can do unaligned loads.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
At the same time change the comment describing the instruction the same
way than other instruction, so that the code is easier to read and search.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We only emulate UP SH4, however as the tas.b instruction is used in the GNU
libc, this improve linux-user emulation.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
synco is a SH4-A only instruction.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This doesn't change the generated code on x86, but optimizes it on most
RISC architectures and makes the code simpler to read.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Using extr and avoiding intermediate temps.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
There is no need to save flags when entering and exiting the delay slot.
They can be saved only when reaching the end of the TB. If the TB is
interrupted before by an exception, they will be restored using
restore_state_to_opc.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
In case of exception, there is no need to call tcg_gen_exit_tb as the
exception helper won't return.
Also fix a few cases where BS_BRANCH is called instead of BS_EXCP.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
When stopping the translation because the state has changed, goto_tb
should not be used as it might link TB with different flags.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Instead of using one bit of the env flags to store the condition of the
next delay slot, use a separate global. It simplifies reading and
writing the flags variable and also removes some confusion between
ctx->envflags and env->flags.
Note that the global is first transfered to a temp in order to be
able to discard the global before the brcond.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
DELAY_SLOT_TRUE is used as a dynamic condition for the branch after the
delay slot instruction. It is not used in code generation, so there is
no need to including in the TB state.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Now that ctx->flags has been split, it becomes clear that
DELAY_SLOT_CLEARME has not impact on the code generation: in both case
ctx->envflags is cleared, either by clearing all the flags, or by
setting it to 0. This is left-over from pre-TCG era.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
There is a confusion (and not only in the SH4 target) between tb->flags,
env->flags and ctx->flags. To avoid it, split ctx->flags into
ctx->tbflags and ctx->envflags. ctx->tbflags stays unchanged during the
whole TB translation, while ctx->envflags evolves and is kept in sync
with env->flags using TCG instructions. ctx->envflags now only contains
the part that of env->flags that is contained in the TB state, i.e. the
DELAY_SLOT* flags.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
When running certain HMP commands ("info registers", "info cpustats",
"info tlb", "nmi", "memsave" or dumping virtual memory) with the "none"
machine, QEMU crashes with a segmentation fault. This happens because the
"none" machine does not have any CPUs by default, but these HMP commands
did not check for a valid CPU pointer yet. Add such checks now, so we get
an error message about the missing CPU instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1484309555-1935-1-git-send-email-thuth@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
