[LLVMdev] The status of MC-COFF(aka integrated-as)/cygming

[NAKAMURA Takumi]

Good midnight, everyone!

Now clang/llvm on cygming can be built selfhost with a few patch ;)
I am trying to build stage2 clang/llvm with -integrated-as.
I met some issues below;

* MC-COFF emits .comm as individual "linkonce" section.

  Thus, the order in .bss must be differ against one assembled by GNU as.
  It might have bugs and I am investigating now.

* Trail alignment shim of each section

  GNU as emits alignment to trail of .text. MC-COFF does not.

* MC-COFF does relaxation more strongly

  I saw a few cases, MC-COFF emits disp8 for branch (although GNU as
emits disp32).
  At a glance, It might be correct.
  I have not met regression yet.

* (Investigating)

  I saw a few cases; MC-COFF emits quite different instruction sequences.
  It might be my mistake, still in investigating.

I will file one for serious issues.


have a nice hacking! ...Takumi