> You're misunderstanding how this code works. In cfglayout mode, > there is no "order" in the basic blocks such that > BLOCK_FOR_INSN(NEXT_INSN(BB_END(BB)) ) == BB->next_bb. This means > that you can fall through to other blocks than next_bb.
Thanks for the tip, I figured out what was really happening. Which leads to the next question: What's the right way to keep an asm() from being loop invariant? I've got a case where an inline asm() is passed a pointer (the pointer is invariant) but internally dereferences it (the pointed-at memory is *not* invariant). However, loop-invariant.c is pulling it out of the loop anyway. Making the whole asm() volatile works, but that seems like overkill to me.
