rust-lang/rust integration metabug

[japaric]

• Build missing intrinsics from compiler-rt (C) source code Build missing intrinsics from compiler-rt (C) source code #63
• Put weak memcpy et al symbols behind an opt-in Cargo feature Put weak memcpy et al symbols behind an opt-in Cargo feature #64
• Test our implementations against libgcc Test our implementations against libgcc #65
• Rename this repo to compiler-builtins
• Transfer to rust-lang-nursery
• compile functions with hidden visibility
• i128 support - i128 intrinsics #133
• "C" ABI -> "aapcs" on ARM - __aeabi_ functions should use the AAPCS calling convention, at least with LLVM 4.0+ #116 use AAPCS calling convention on all aeabi intrinsics #141

cc @alexcrichton

[est31]

Note, now that rust-lang/rust#38482 is merged, i128 support is required as well.

Just using the C implementation is not enough as the C implementation only is enabled and works on non windows 64 bit platforms (that was the reason the PR had to implement the intrinsics in Rust in the first place).

See #133 that attempts to add support.

Also note that during the making of that PR I not just had linker issues with calls to panic, it also complained about calls to eh_personality, which in some cases survives while panic does not.

[japaric]

Added i128 support to the list. After #133 lands, we would still need the famility of floatundif intrinsics, I believe.

Also added changing the ABI of (some?) intrinsics from C to aapcs on ARM. cc #116

compile functions with hidden visibility

And I believe this issue was fixed in rust-lang/rust proper? cc @alexcrichton

[est31]

With #133 merged, the following float functions are required to be ported:

• __fixsfti
• __fixdfti
• __fixunsdfti
• __fixunssfti
• __floattidf
• __floattisf
• __floatuntidf
• __floatuntisf

They all need extern "unadjusted" instead of extern "C" on windows.