Don't invalidate TB with the end of zero overhead loop when LBEG or LEND
change. Instead encode the distance from the start of the page where the
TB starts to the LEND in the TB cs_base and generate loopback code when
the next PC matches encoded LEND. Distance to a destination within the
same page and up to a maximum instruction length into the next page is
encoded literally, otherwise it's zero. The distance from LEND to LBEG
is also encoded in the cs_base: it's encoded literally when less than
256 or as 0 otherwise. This allows for TB chaining for the loopback
branch at the end of a loop for the most common loop sizes.
With this change the resulting emulation speed is about 10% higher in
softmmu mode on uClibc-ng and LTP tests. Emulation speed in linux
user mode is a few percent lower because there's no direct TB chaining
between different memory pages. Testing with lower limit on direct TB
chaining range shows gradual slowdown to ~15% for the block size of 64
bytes and ~50% for the block size of 32 bytes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
ISA book documents that the first instruction of zero overhead loop
must fit completely into naturally aligned region of an instruction
fetch unit size. Check that condition and log a message if it's
violated.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
System emulation should provide access to all registers, userspace
emulation should only provide access to unprivileged registers.
Record register flags from GDB register map definition, calculate both
num_regs and num_core_regs if either is zero. Use num_regs in system
emulation, num_core_regs in userspace emulation gdbstub.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Xtensa core may have a number of RAM and ROM areas configured. Record
their size and location from the core configuration overlay and
instantiate them as RAM regions in the SIM machine.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
RER and WER are privileged instructions for accessing external
registers. External register address space is local to processor core.
There's no alignment requirements, addressable units are 32-bit wide
registers.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Configuration overlay does not explicitly say whether there are ICACHE
and DCACHE in the core. Current code uses XCHAL_[ID]CACHE_WAYS to detect
if corresponding cache option is enabled, but that's not correct: on
cores without cache these macros are defined as 1, not as 0.
Check XCHAL_[ID]CACHE_SIZE instead.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Xtensa cores may have two distinct addresses for the static vectors
group. Provide a function to select one of them.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
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>
Max Filippov
Thomas Huth