This version of signal (which does not rely on a notion of userland
processes and is thus excluded from Vhex) follows C99 semantics but does
not generate any signals by default.
Basically, the signal function sets up function pointers and the signal
function calls them. Termination signals call exit() while other signals
call _Exit(), which is a quicker program termination similar to abort().
C99 allows programs to long jump out of signal handlers (!) which is
unbelievably scary because it would bypass stack switching code in Vhex
as well as normal interrupt handler termination in gint.
This is implemented for gint only currently; on Vhex, _Exit() is likely
just going to be a syscall. For CASIOWIN, this is slightly more
difficult, as there is no native exit syscall.
SR.BL=1 could cause problems if setjmp or longjmp is loader over a page
boundary and the second page is not loaded when interrupts are masked.
SR.IMASK=15 is another option, but it seems unnecessary per #1.
Blocking interrupts in longjmp did not make too much sense because the
blocked SR was immediately replaced by the restored one.
* Name the private function __strto_{int,fp} (with leading double
underscores) to avoid name conflicts
* Fix comments of the wrong style
* Fix missing leading double underscores in stdlib_p.h
This change provides an optimized hand-written strlen function for
SuperH targets. The original plan was to declare the C-based naive
version weak and just let the linker figure out the proper one to use,
but unfortunately static libraries don't work like that; ld
intentionally stops at the first version even if it's weak. Instead,
some #ifdef's are used in the C-based strlen to not compile it when
unneeded.
The optimized strlen uses 4-byte accesses and cmp/str.
On sh-generic targets, the headers <bits/cpucap.h> (in C) and
<bits/asm/cpucap.h> (in assembler) provide definitions to acces the
__cpucap symbol which provides information on the CPU.
Currently, a single capability __CPUCAP_SH4ALDSP is defined; it
represents the SH4 extended instructions together with the integrated
DSP instructions. The main uses of this capability are [movua.l]
(unaligned reads) and [ldrc] (built-in tight loops).
Capabilities are initialized to 0 (their safest default) and the runtime
can enable them based on what hardware is running.
