* The stack pointer (SP) register points to the lowest-used address of
a downward-growing stack, so memory address [sp] is used, we can't
modify it.
* In firq_no_switch case, we need to pop sp, which pushed before
_isr_demux function in firq_nest function.
Signed-off-by: Watson Zeng <zhiwei@synopsys.com>
overhaul the thread switch code in epilogue of irq and
exception handling:
* add z_arch_get_next_switch_handle to call z_get_next_switch_handle,
let the scheduler to decide the switch thread. This will also cover
the case of SMP.
* put lots of common codes in macros for thread switch to improve
the maintainablity, readability.
* clean up of some lables to make codes easier to understand
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* for COOP_SCHED case, i.e., PREEMPT_ENABLED is not enabled, the
idle thread will block other threads which is not correct.
* remove the check of PREEMPT_ENABLED in the epilogue of irq and
exception handling. Let the scheduler (should_preempt()) decide
whether the thread should be preempted.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
These are not part of the generic kernel to
architecture interface, rename appropriately to
reflect they are ARC-specific.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit refactors kernel and arch headers to establish a boundary
between private and public interface headers.
The refactoring strategy used in this commit is detailed in the issue
This commit introduces the following major changes:
1. Establish a clear boundary between private and public headers by
removing "kernel/include" and "arch/*/include" from the global
include paths. Ideally, only kernel/ and arch/*/ source files should
reference the headers in these directories. If these headers must be
used by a component, these include paths shall be manually added to
the CMakeLists.txt file of the component. This is intended to
discourage applications from including private kernel and arch
headers either knowingly and unknowingly.
- kernel/include/ (PRIVATE)
This directory contains the private headers that provide private
kernel definitions which should not be visible outside the kernel
and arch source code. All public kernel definitions must be added
to an appropriate header located under include/.
- arch/*/include/ (PRIVATE)
This directory contains the private headers that provide private
architecture-specific definitions which should not be visible
outside the arch and kernel source code. All public architecture-
specific definitions must be added to an appropriate header located
under include/arch/*/.
- include/ AND include/sys/ (PUBLIC)
This directory contains the public headers that provide public
kernel definitions which can be referenced by both kernel and
application code.
- include/arch/*/ (PUBLIC)
This directory contains the public headers that provide public
architecture-specific definitions which can be referenced by both
kernel and application code.
2. Split arch_interface.h into "kernel-to-arch interface" and "public
arch interface" divisions.
- kernel/include/kernel_arch_interface.h
* provides private "kernel-to-arch interface" definition.
* includes arch/*/include/kernel_arch_func.h to ensure that the
interface function implementations are always available.
* includes sys/arch_interface.h so that public arch interface
definitions are automatically included when including this file.
- arch/*/include/kernel_arch_func.h
* provides architecture-specific "kernel-to-arch interface"
implementation.
* only the functions that will be used in kernel and arch source
files are defined here.
- include/sys/arch_interface.h
* provides "public arch interface" definition.
* includes include/arch/arch_inlines.h to ensure that the
architecture-specific public inline interface function
implementations are always available.
- include/arch/arch_inlines.h
* includes architecture-specific arch_inlines.h in
include/arch/*/arch_inline.h.
- include/arch/*/arch_inline.h
* provides architecture-specific "public arch interface" inline
function implementation.
* supersedes include/sys/arch_inline.h.
3. Refactor kernel and the existing architecture implementations.
- Remove circular dependency of kernel and arch headers. The
following general rules should be observed:
* Never include any private headers from public headers
* Never include kernel_internal.h in kernel_arch_data.h
* Always include kernel_arch_data.h from kernel_arch_func.h
* Never include kernel.h from kernel_struct.h either directly or
indirectly. Only add the kernel structures that must be referenced
from public arch headers in this file.
- Relocate syscall_handler.h to include/ so it can be used in the
public code. This is necessary because many user-mode public codes
reference the functions defined in this header.
- Relocate kernel_arch_thread.h to include/arch/*/thread.h. This is
necessary to provide architecture-specific thread definition for
'struct k_thread' in kernel.h.
- Remove any private header dependencies from public headers using
the following methods:
* If dependency is not required, simply omit
* If dependency is required,
- Relocate a portion of the required dependencies from the
private header to an appropriate public header OR
- Relocate the required private header to make it public.
This commit supersedes #20047, addresses #19666, and fixes#3056.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
* In ARC, pop reg ==> sp=sp-4; *sp= b; The original codes have bug that
the save of ilink (st ilink [sp]) will crash the interruptted stack's
content. This commit fixes this bug and makes the codes easier to
understand
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
we should not rely on that eret has a copy of ilink in fast
irq handling. This will cause crash for hs cores.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
For the old codes, if nest interrupts come out after _isr_wrapper
and before _check_nest_int_by_irq_act, then multi-bits in irq_act
will be set, this will result irq stack will not be switched in
correctly
As a fix, it's still need to use nest interrupt counter to do
interrupt stack switch as before
The difference is in the past exc_nest_count is used, but here
_kernel.nested/_kernel.cpus[cpu_id].nested is used.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* it's based on ARC SecureShield
* add basic secure service in arch/arc/core/secureshield
* necesssary changes in arch level
* thread switch
* irq/exception handling
* initialization
* add secure time support
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* modify the reset flow for SMP
* add smp related initialization
* implement ipi related functions
* implement thread switch in isr/exception
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* use IRQ_ACT to check nest interrupt
* implement an asm macro for nest interrupt check
* no need to use exc_nest_count, remove it
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* do not use a specific variable (saved_r0/saved_sp) to free r0
/exchange sp, but use stack to do that.
* it will make code scalable, e.g. for SMP, no need to define
variables for each core
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* if thread switchs in interrupt, the target sp must be in
thread's kernel stack, no need to do hardware sp switch
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
If the offset within the thread struct to the
ARC arch-specific 'relinquish_cause' member is too
large, ld_s instructions referencing it will not
compile. This happens easily if CONFIG_THREAD_NAME
reserves a name buffer within the thread struct, since
all the arch-specific members come last.
Use the regular 'ld' instruction instead.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
* here use new style z_arch_switch,i.e. CONFIG_USE_SWITCH
to replace old swap mechnism.
* it's also required by SMP support
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* it's not reliable to use exc_nest_count to decide nest interrupt.
A better option is to use IRQ_ACT
* ext_nest_count is just used to switch interrupt stack
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Update reserved function names starting with one underscore, replacing
them as follows:
'_k_' with 'z_'
'_K_' with 'Z_'
'_handler_' with 'z_handl_'
'_Cstart' with 'z_cstart'
'_Swap' with 'z_swap'
This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.
Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.
Various generator scripts have also been updated as well as perf,
linker and usb files. These are
drivers/serial/uart_handlers.c
include/linker/kobject-text.ld
kernel/include/syscall_handler.h
scripts/gen_kobject_list.py
scripts/gen_syscall_header.py
Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
* the original stack check codes have no consideration
for userspace case. This will wrong cause possible stack
check exception.
* this commit refactors the arc stack check support to
support the usperspace.
* this commit fixes#7885. All the failed tests in #7885
are run again to verify this commit. The test results are ok
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
The metairq feature exposed the fact that all of our arch code (and a
few mistaken spots in the scheduler too) was trying to interpret
"preemptible" threads independently.
As of the scheduler rewrite, that logic is entirely within sched.c and
doing it externally is redundant. And now that "cooperative" threads
can be preempted, it's wrong and produces test failures when used with
metairq threads.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
* call the _check_stack_sentinel in unnested isr
return.
* for firq, _check_stack_sentinel is called in kernel
isr stack because the limitation of banked register
* for normal irq, _check_stak_sentinel is called in
the interruptted thread stack
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* add the implementation of syscall
* based on 'trap_s' intruction, id = 3
* add the privilege stack
* the privilege stack is allocted with thread stack
* for the kernel thread, the privilege stack is also a
part of thread stack, the start of stack can be configured
as stack guard
* for the user thread, no stack guard, when the user stack is
overflow, it will fall into kernel memory area which requires
kernel privilege, privilege violation will be raised
* modify the linker template and add MPU_ADDR_ALIGN
* add user space corresponding codes in mpu
* the user sp aux reg will be part of thread context
* When user thread is interruptted for the 1st time, the context is
saved in user stack (U bit of IRQ_CTLR is set to 1). When nest
interrupt comes, the context is saved in thread's privilege stack
* the arc_mpu_regions.c is moved to board folder, as it's board
specific
* the above codes have been tested through tests/kernel/mem_protect/
userspace for MPU version 2
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Refering the ARM's implementation, the initial support of memory
domain in ARC is added:
* changes in MPU drivers
* changes in Kconfig
* codes to configure memory domain during thread swap
* changes in linker script template
* memory domain related macro definitions
the commited codes are simply tested through
samples/mpu/mem_domain_apis_test.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* add arc mpu driver
* modify the corresponding kconfig and kbuild
* currently only em_starterkit 2.2's em7d configuration
has mpu feature (mpu version 2)
* as the minimum region size of arc mpu version 2 is 2048 bytes and
region size should be power of 2, the stack size of threads
(including main thread and idle thread) should be at least
2048 bytes and power of 2
* for mpu stack guard feature, a stack guard region of 2048 bytes
is generated. This brings more memory footprint
* For arc mpu version 3, the minimum region size is 32 bytes.
* the codes are tested by the mpu_stack_guard_test and stackprot
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* add nested interrupt support for interrupts
+ use a varibale exc_nest_count to trace nest interrupt and exception
+ regular interrupts can be nested by regular interrupts and fast
interrupts
+ fast interrupt's priority is the highest, cannot be nested
* remove the firq stack and exception stack
+ remove the coressponding kconfig option
+ all interrupts (normal and fast) and exceptions will be handled
in the same stack (_interrupt stack)
+ the pros are, smaller memory footprint (no firq stack), simpler
stack management, simpler codes, etc.. The cons are, possible
10-15 instructions overhead for the case where fast irq nests
regular irq
* add the case of ARC in test/kernel/gen_isr_table
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Here are the main changes:
* board: Update EMSK onboard resources such as Button, Switch and LEDs
+ update soc.h for em7d, em9d, em11d
+ update board.h for em_starterkit board
* arc: Add floating point support and code density support
+ add kconfig configuration
+ add compiler options
+ add register definitions, marcos, assembly codes
+ fixes in existing codes and configurations.
* arc: Update detailed board configurations for cores of emsk 2.3
* script: Provide arc_debugger.sh for debugging em_starterkit board
+ make BOARD=em_starterkit debug
This will start openocd server for emsk, and arc gdb will connect
to this debug server, user can run `continue` command if user just
want to run the application, or other commands if debugging needed.
+ make BOARD=em_starterkit debugserver
This will start an openocd debugger server for emsk, and user can
connect to this debugserver using arc gdb and do what they want to.
+ make BOARD=em_starterkit flash
This will download the zephyr application elf file to emsk,
and run it.
Signed-off-by: Huaqi Fang <huaqi.fang@synopsys.com>
- There's no clear need to disable frame pointers if this feature is
used, remove this directive.
- The 'top' and 'base' terms are reversed. The 'base' is the high
address of the stack. The top is the lowest address, where we cannot
push further down. Fixup member and offset names to correspond to how
these terms are used in hardware documentation.
- Use correct pointers for stack top location
- Fatal exceptions now go through _NanoFatalErrorHandler to report the
faulting ip and thread.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This avoids asm files from having to explicitly define the _ASMLANGUAGE
symbol themselves.
Change-Id: I71f5a169f75d7443a58a0365a41c55b20dae3029
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
These two fields in the thread structure control the preemptibility of a
thread.
sched_locked is decremented when the scheduler gets locked, which means
that the scheduler is locked for values 0xff to 0x01, since it can be
locked recursively. A thread is coop if its priority is negative, thus
if the prio field value is 0x80 to 0xff when looked at as an unsigned
value.
By putting them end-to-end, this means that a thread is non-preemptible
if the bundled value is greater than or equal to 0x0080. This is the
only thing the interrupt exit code has to check to decide to try a
reschedule or not.
Change-Id: I902d36c14859d0d7a951a6aa1bea164613821aca
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Some thread fields were 32-bit wide, when they are not even close to
using that full range of values. They are instead changed to 8-bit fields.
- prio can fit in one byte, limiting the priorities range to -128 to 127
- recursive scheduler locking can be limited to 255; a rollover results
most probably from a logic error
- flags are split into execution flags and thread states; 8 bits is
enough for each of them currently, with at worst two states and four
flags to spare (on x86, on other archs, there are six flags to spare)
Doing this saves 8 bytes per stack. It also sets up an incoming
enhancement when checking if the current thread is preemptible on
interrupt exit.
Change-Id: Ieb5321a5b99f99173b0605dd4a193c3bc7ddabf4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
This will allow for an enhancement when checking if the thread is
preemptible when exiting an interrupt.
Change-Id: If93ccd1916eacb5e02a4d15b259fb74f9800d6f4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Some kernel operations, like scheduler locking can be optmized out,
since coop threads lock the scheduler by their very nature. Also, the
interrupt exit path for all architecture does not have to do any
rescheduling, again by the nature of non-preemptible threads.
Change-Id: I270e926df3ce46e11d77270330f2f4b463971763
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
The way the ready thread cache was implemented caused it to not always
be "hot", i.e. there could be some misses, which happened when the
cached thread was taken out of the ready queue. When that happened, it
was not replaced immediately, since doing so could mean that the
replacement might not run because the flow could be interrupted and
another thread could take its place. This was the more conservative
approach that insured that moving a thread to the cache would never be
wasted.
However, this caused two problems:
1. The cache could not be refilled until another thread context-switched
in, since there was no thread in the cache to compare priorities
against.
2. Interrupt exit code would always have to call into C to find what
thread to run when the current thread was not coop and did not have the
scheduler locked. Furthermore, it was possible for this code path to
encounter a cold cache and then it had to find out what thread to run
the long way.
To fix this, filling the cache is now more aggressive, i.e. the next
thread to put in the cache is found even in the case the current cached
thread is context-switched out. This ensures the interrupt exit code is
much faster on the slow path. In addition, since finding the next thread
to run is now always "get it from the cache", which is a simple fetch
from memory (_kernel.ready_q.cache), there is no need to call the more
complex C code.
On the ARM FRDM K64F board, this improvement is seen:
Before:
1- Measure time to switch from ISR back to interrupted task
switching time is 215 tcs = 1791 nsec
2- Measure time from ISR to executing a different task (rescheduled)
switch time is 315 tcs = 2625 nsec
After:
1- Measure time to switch from ISR back to interrupted task
switching time is 130 tcs = 1083 nsec
2- Measure time from ISR to executing a different task (rescheduled)
switch time is 225 tcs = 1875 nsec
These are the most dramatic improvements, but most of the numbers
generated by the latency_measure test are improved.
Fixes ZEP-1401.
Change-Id: I2eaac147048b1ec71a93bd0a285e743a39533973
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
When going into DEEP_SLEEP mode, the ARC core now saves
its context. This includes:
- All core registers
- Stack pointer
- Program counter (restored by jumping to the restore code)
The arc reset code now checks if the GPS0 bit 2 is set.
This is similar to the behavior of the x86 core done by
the QMSI bootloader which is setting GPS0 bit 1 in order
to call the restore path instead of cold boot path.
The sample has been adapted in order to support the ARC.
Jira: ZEP-1222
Change-Id: I375f03b16b8a5fd1f07ead55cf7e4947d6290c9f
Signed-off-by: Julien Delayen <julien.delayen@intel.com>
In order to resume the ARC from deep sleep,
the interrupts need to be restored.
The FIRQ stack needs to be saved and restored
when performing sleep operations.
During early initialization, the sp in the 2nd register bank
is made to refer to _firq_stack.
This allows for the FIRQ handler to use its own stack.
Fast Interrupts cannot be used after sleep if this information
is not restored.
This patch adds the suspend and resume functions.
Jira: ZEP-1223
Change-Id: Ic81980f05aee6c1f7b8c46c743f2648c65b29486
Signed-off-by: Julien Delayen <julien.delayen@intel.com>
There was a lot of duplication between architectures for the definition
of threads and the "nanokernel" guts. These have been consolidated.
Now, a common file kernel/unified/include/kernel_structs.h holds the
common definitions. Architectures provide two files to complement it:
kernel_arch_data.h and kernel_arch_func.h. The first one contains at
least the struct _thread_arch and struct _kernel_arch data structures,
as well as the struct _callee_saved and struct _caller_saved register
layouts. The second file contains anything that needs what is provided
by the common stuff in kernel_structs.h. Those two files are only meant
to be included in kernel_structs.h in very specific locations.
The thread data structure has been separated into three major parts:
common struct _thread_base and struct k_thread, and arch-specific struct
_thread_arch. The first and third ones are included in the second.
The struct s_NANO data structure has been split into two: common struct
_kernel and arch-specific struct _kernel_arch. The latter is included in
the former.
Offsets files have also changed: nano_offsets.h has been renamed
kernel_offsets.h and is still included by the arch-specific offsets.c.
Also, since the thread and kernel data structures are now made of
sub-structures, offsets have to be added to make up the full offset.
Some of these additions have been consolidated in shorter symbols,
available from kernel/unified/include/offsets_short.h, which includes an
arch-specific offsets_arch_short.h. Most of the code include
offsets_short.h now instead of offsets.h.
Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Fix the error in thread rescheduling:
Fix Fast IRQ exit routine error when it reschedules threads if
(prio >= 0) || (sched_locked == 0) || (next_thread == _current),
while the correct condition for thread rescheduling is:
(prio >= 0) && (sched_locked == 0) && (next_thread != _current),
Fix regular IRQ error when the regular IRQ exit routine rescheduled
threads when (next_thread == _current) instead of
(next_thread != current).
Increased IDLE_STACK_SIZE for ARC architecture, to hold saved
registers.
Change-Id: I1d87a968e231e13822844b7564567e6ca310cde2
Signed-off-by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
- the interrupt (both regular and fast) now does not do rescheduling
if the current thread is a coop thread or if the scheduler is not locked
- the _nanokernel.flags cache of _current.flags is not used anymore
(could be a source of bugs) and is not needed in the scheduling algo
- there is no 'task' field in the _nanokernel anymore: scheduling routines
call _get_next_ready_thread instead
- the _nanokernel.fiber field is replaced by a more sophisticated
ready_q, based on the microkernel's priority-bitmap-based one
- thread initialization initializes new fields in the tcs, and does not
initialize obsolete ones
- nano_private includes nano_internal.h from the unified directory
- The FIBER, TASK and PREEMPTIBLE flags do not exist anymore: the thread
priority drives the behaviour
- the tcs uses a dlist for queuing in both ready and wait queues instead
of a custom singly-linked list
- other new fields in the tcs include a schedule-lock count, a
back-pointer to init data (when the task is static) and a pointer to
swap data, needed when a thread pending on _Swap() must be passed more
then just one value (e.g. k_stack_pop() needs an error code and data)
- the 'fiber' and 'task' fields of _nanokernel are replaced with an O(1)
ready queue (taken from the microkernel)
- fiberRtnValueSet() is aliased to _set_thread_return_value since it
also operates on preempt threads now
- _set_thread_return_value_with_data() sets the swap_data field in
addition to a return value from _Swap()
- convenience aliases are created for shorter names:
- _current is defined as _nanokernel.current
- _ready_q is defined as _nanokernel.ready_q
- _Swap() sets the threads's return code to -EAGAIN before swapping out
to prevent timeouts to have to set it (solves hard issues in some
kernel objects).
Change-Id: Ib9690173cbc36c36a9ec67e65590b40d758673de
Signed-off-by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
For the EM Starterkit, one SOC I will soon be adding is EM7D.
This SOC has FIRQ, but only has one register bank.
Thus the interrupt handling for FIRQ needs to be different
when CONFIG_RGF_NUM_BANKS==1. The handler must instead push
registers onto the stack in the same stack frame layout that RIRQ uses.
This allows for context switch to be easily done since its compatible.
The common interrupt entry point _isr_enter must save r0 before using
it, because in the FIRQ 1-bank case, it would be destroyed otherwise.
So a global variable named saved_r0 has been added for this reason.
The stack cannot be used to save r0, because it first has to determine
whether its FIRQ or RIRQ here. This change has been tested on the
EM Starterkit with EM7D SOC changes -- coming soon. To make the review
easier, these 3 files are submitted first.
Also, exceptions will no longer use the _firq_stack.
This stack is not needed in the 1-bank case, but an exception stack
is needed. I've added a new stack called _exception_stack,
and made it be 512B, which should be enough for one exception.
See ZEP-966
Change-Id: I6f228b840da7c4db440dd1cfef4ae25336c87f0d
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
Since firq utilizes a 2nd register bank, and since all of those
many GPRs can be used, the strategy here is to save extra registers,
such as lp_count, lp_start, lp_end into callee saved registers.
These registers are safe to use because the C-ABI followed by the
compiler will cause these to be spilled to the stack if a C function
wants to use them. By selecting upper GPRs, r23-r25, it is very unlikely
the compiler will spill them. This improvement, therefore, can avoid a
d-cache miss since we are avoding memory altogether when saving these.
The struct firq_regs is no longer needed.
Change-Id: I7c0d061908a90376da7a0101b62e804647a20443
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
The .nd on a branch is WRONG if its an unconditional branch. Not needed.
On conditional branches its a compiler feature that is not yet functional
with ARC targets. Typical code for this compiler can use .d to put
something in the delay slot of an instruction, but using .nd is probably
never wanted.
Change-Id: If1017c468e6e7af269ea73daeb4bc223dcc0059f
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
Code size can be reduced by replacing ld and st
with ld_s and st_s (if target registers are r0-r3).
Change-Id: Ia70f0aff07fe41a0cfeff2d59dcdadf7c88e1ae8
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
