the WinCE device emulator has a bug with 'blx lr', and a blx_lr_bug bool was introduced to avoid that bug and use some other construct when it occurs. I seems more sensible to just avoid using 'blx lr' at all, avoiding additional runtime tests.

+1 blx_lr_bug is a gross hack (i'm to blame) The only hazard I can think of in this patch is that IP is not a managed register, and is used implicitly as scratch in various instructions. I reviewed underrunProtect(), and it's not used there, I'm pretty sure. The code path in asm_regarg that calls findSpecificRegFor(p, r), will be a problem if r == IP, since IP is not a managed register.

(In reply to comment #2) > The code path in asm_regarg that calls findSpecificRegFor(p, r), will be a > problem if r == IP, since IP is not a managed register. Actually, that could be a problem as that code path looks like it'll be hit in some cases. There are two obvious solutions that I can see: • Change the p->isExtant() check to "(p->isExtant()) || (r == IP)". This is perhaps a little fragile, but it looks sane at a glance. • Use the register allocation API to get a register for the value, then BLX to that register. This is more complicated perhaps, but safer.

Edwin was right in comment 2. It crashed in the findSpecificRegFor path. Using Jacob's first suggestion, it seems to work properly.

In then end, I haven't managed to get a better solution to work, and I don't care enough about this codepath (unused in tracemonkey) to spend more time on it, however interesting it can be. I'm therefore going this road: <edwsmith> hey, guys, here's another proposition for you why dont we rip out blr_lr_broken() and blr_lr_bug, and just put #ifdef WINCE around the "bug" case in asm_call() <jbramley> Works for me. I used UNDER_CE instead of WINCE, though.

The armv4t patch I'm working on doesn't depend on that anymore.

With this patch we no longer have to detect the broken emulator, so don't need this weird armasm file that didn't belong under MMgc anyway.

Landed the nanojit part. http://hg.mozilla.org/projects/nanojit-central/rev/9e1146b15442

nanojit part in TR: http://hg.mozilla.org/tamarin-redux/rev/211232d5bd76 TR part in TR: http://hg.mozilla.org/tamarin-redux/rev/9804879bc296