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>
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>
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>
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
