Intel MCU System V ABI are incompartible with i386 System V ABI:
o Minimum instruction set is Intel Pentium ISA minus x87 instructions
o No x87 or vector registers
o First three args are passed in %eax, %edx and %ecx
o Full specification available here:
https://github.com/hjl-tools/x86-psABI/wiki/iamcu-psABI-0.7.pdf
newlib/
* configure.host: Add new ix86-*-elfiamcu target
newlib/libc/include/
* setjmp.h: Change _JBLEN for Intel MCU target
newlib/libc/machine/i386/
* memchr.S: (memchr) Target-specific size-optimized version
* memcmp.S: (memcmp) Likewise
* memcpy.S: (memcpy) Likewise
* memmove.S: (memmove) Likewise
* memset.S: (memset) Likewise
* setjmp.S: (setjmp) Likewise
* strchr.S: (strchr) Likewise
* strlen.S: (strlen) Likewise
newlib/libc/stdlib/
* srtold.c: (__flt_rounds) Disable for Intel MCU
* libc/machine/i386/i386mach.h: added SOTYPE_FUNCTION to set type
of global entry points if _I386MACH_NEED_SOTYPE_FUNCTION is defined;
Added __CLI and __STI macros (controlled via
_I386MACH_ALLOW_HW_INTERRUPTS macro).
* libc/machine/i386/f_atan2.S libc/machine/i386/f_atan2f.S
libc/machine/i386/f_frexp.S libc/machine/i386/f_frexpf.S
libc/machine/i386/f_ldexp.S libc/machine/i386/f_ldexpf.S
libc/machine/i386/f_log.S libc/machine/i386/f_log10.S
libc/machine/i386/f_log10f.S libc/machine/i386/f_logf.S
libc/machine/i386/f_tan.S libc/machine/i386/f_tanf.S
libc/machine/i386/memchr.S libc/machine/i386/memcmp.S
libc/machine/i386/memcpy.S libc/machine/i386/memmove.S
libc/machine/i386/memset.S libc/machine/i386/setjmp.S
libc/machine/i386/strchr.S libc/machine/i386/strlen.S:
(that's libc/machine/i386/*.S) added SOTYPE_FUNCTION(symbol)
for all global entry points.
* libc/machine/i386/setjmp.S: removed code replicated in
libc/machine/i386/i386mach.h and included i386mach.h instead;
Use __CLI and __STI instead of cli and sti.
