Previous to this patch, the "**b" in "a**b" had its own parse node with
just one item (the "b"). Now, the "b" is just the last element of the
power parse-node. This saves (a tiny bit of) RAM when compiling.
Passing an mp_uint_t to a %d printf format is incorrect for builds where
mp_uint_t is larger than word size (eg a nanboxing build). This patch
adds some simple casting to int in these cases.
If the heap is locked, or memory allocation fails, then calling a bound
method will still succeed by allocating the argument state on the stack.
The new code also allocates less stack than before if less than 4
arguments are passed. It's also a tiny bit smaller in code size.
This was done as part of the ESA project.
This new compile-time option allows to make the bytecode compiler
configurable at runtime by setting the fields in the mp_dynamic_compiler
structure. By using this feature, the compiler can generate bytecode
that targets any MicroPython runtime/VM, regardless of the host and
target compile-time settings.
Options so far that fall under this dynamic setting are:
- maximum number of bits that a small int can hold;
- whether caching of lookups is used in the bytecode;
- whether to use unicode strings or not (lexer behaviour differs, and
therefore generated string constants differ).
Reduces code size by 112 bytes on Thumb2 arch, and makes assembler faster
because comparison can be a simple equals instead of a string compare.
Not all ops have been converted, only those that were simple to convert
and reduced code size.
The chunks of memory that the parser allocates contain parse nodes and
are pointed to from many places, so these chunks cannot be relocated
by the memory manager. This patch makes it so that when a chunk is
shrunk to fit, it is not relocated.
These can be used to insert arbitrary checks, polling, etc into the VM.
They are left general because the VM is a highly tuned loop and it should
be up to a given port how that port wants to modify the VM internals.
One common use would be to insert a polling check, but only done after
a certain number of opcodes were executed, so as not to slow down the VM
too much. For example:
#define MICROPY_VM_HOOK_COUNT (30)
#define MICROPY_VM_HOOK_INIT static uint vm_hook_divisor = MICROPY_VM_HOOK_COUNT
#define MICROPY_VM_HOOK_POLL if (--vm_hook_divisor == 0) { \
vm_hook_divisor = MICROPY_VM_HOOK_COUNT;
extern void vm_hook_function(void);
vm_hook_function();
}
#define MICROPY_VM_HOOK_LOOP MICROPY_VM_HOOK_POLL
#define MICROPY_VM_HOOK_RETURN MICROPY_VM_HOOK_POLL
The new block protocol is:
- readblocks(self, n, buf)
- writeblocks(self, n, buf)
- ioctl(self, cmd, arg)
The new ioctl method handles the old sync and count methods, as well as
a new "get sector size" method.
The old protocol is still supported, and used if the device doesn't have
the ioctl method.
Paul Sokolovsky