Assuming proper C99 language support, we can select "the int type as big as
a pointer" (most of the time) or "the 64-bit int type" (nanboxing with
REPR_D), and then define everything else automatically.
This simplifies port configuration files. And the types can still be
overridden if needed.
Signed-off-by: Jeff Epler <jepler@unpythonic.net>
Most MCUs apart from Cortex-M0 with Thumb 1 have an instruction
for computing the "high part" of a multiplication (e.g., the upper
32 bits of a 32x32 multiply).
When they do, gcc uses this to implement a small and fast
overflow check using the __builtin_mul_overflow intrinsic, which
is preferable to the guard division method previously used in smallint.c.
However, in contrast to the previous mp_small_int_mul_overflow
routine, which checks that the result fits not only within mp_int_t
but is SMALL_INT_FITS(), __builtin_mul_overflow only checks for
overflow of the C type. As a result, a slight change in the code
flow is needed for MP_BINARY_OP_MULTIPLY.
Other sites using mp_small_int_mul_overflow already had the
result value flow through to a SMALL_INT_FITS check so they didn't
need any additional changes.
Do similarly for the _ll and _ull multiply overflows checks.
Signed-off-by: Jeff Epler <jepler@gmail.com>
Return the result of called function. If exception happened, return
MP_OBJ_NULL. Allows to use mp_call_function_*_protected() with callbacks
returning values, etc.
Header files that are considered internal to the py core and should not
normally be included directly are:
py/nlr.h - internal nlr configuration and declarations
py/bc0.h - contains bytecode macro definitions
py/runtime0.h - contains basic runtime enums
Instead, the top-level header files to include are one of:
py/obj.h - includes runtime0.h and defines everything to use the
mp_obj_t type
py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
and defines everything to use the general runtime support functions
Additional, specific headers (eg py/objlist.h) can be included if needed.
