Armv8-M Baseline, ie thumbv8m.base-none-eabi, is a superset of the
Armv6-M architecture profile. As it shares almost the same instruction
set, this commit copies the configuration for thumbv6m-none-eabi to
enable it.
1. Avoid undefined references as:
undefined reference to `__modsi3'
undefined reference to `__umodsi3'
2. We can't remove assembly implementations that are not in the list
Although compiler-rt presumably has a more optimized implementation written in
assembly, it appears buggy for whatever reason, causing #173.
For now let's see if integration into rust-lang/rust will work with the
Rust-defined implementation!
This is an attempt to tidy up the definition of intrinsics by making them more
rust-like at the definition site and using traits instead of macros for the
definition. Additionally the helper macro, `intrinsics!`, now fills in a
definition for #[cfg]'d off intrinsics when compiling with C code
on ARMv7-M processors, divmoddi4 was calling mulodi4 and mulodi4 was calling
divmoddi4 leading to infinite recursion. This commit breaks the cycle by using
wrapping multiplication in divmoddi4.
fixes#145
- multi3: there's no aeabi equivalent
- divmod{s,d}i4: these are directly called by __aeabi_{l,i}divmod
- add{s,d}f3: required by the C sub{s,d}f3 implementation
but make sure they also use the AAPCS calling convention
also, on ARM, inline(always) the actual implementation of the intrinsics so we
end with code like this:
```
00000000 <__aeabi_dadd>:
(implementation here)
```
instead of "trampolines" like this:
```
00000000 <__aeabi_dadd>:
(shuffle registers)
(call __adddf3)
00000000 <__adddf3>:
(implementation here)
```
closes#116
Two reasons:
* the C versions __divti3 and __modti3 are apparently broken,
at least when used in quickcheck. They change their own arguments.
* compiler_rt's support for mips is disabled already on clang [1].
Its desireable to support working "cargo test" on that compiler
as well, and not greet the tester with linker errors.
[1]: http://llvm.org/viewvc/llvm-project?view=revision&revision=224488