<@pcwalton> strcat: it would be nice to have if foo == true just compile
            into mov eax,foo; test eax,eax; jne ... instead of mov
            eax,whatever; cmp eax,1; jne ...
<@pcwalton> err
<@pcwalton> mov eax,whatever; cmp al,1; jne ...
< strcat> yeah
< strcat> pcwalton: once the range asserts are there, LLVM will compile
          trunc to i1 and then a br to that
< strcat> that's what clang does
< strcat> if you don't put range asserts, it uses an AND for the trunc
<@pcwalton> eww
<@pcwalton> and al,feh I guess?
<@pcwalton> err
<@pcwalton> what am I on
<@pcwalton> and al,1
< strcat> pcwalton: yeah
< strcat> that's one of the things the range asserts will be good for
<@pcwalton> does and set the condition codes?
< strcat> pcwalton: not sure
< strcat> pcwalton: I'm just trying to copy clang as closely as possible
          and not worry about the details :P
< strcat> pcwalton: the LLVM optimizations seem to be very specialized
          for what clang outputs
<@pcwalton> not surprising
< strcat> pcwalton: because even with the range assert, I don't think it
          will avoid the cmp unless you do the trunc and br yourself
< strcat> they do a specific optimization for trunc when ranges are known
          (for clang)