On 10/20/2015 05:22 PM, Jeff Law wrote: > On 10/20/2015 10:15 AM, Andrew Haley wrote: >>> But in that case, what do we guarantee. >>> >>> We certainly don't guarantee that those objects will be in their >>> requested register at any point other than at the asm statements. >> >> OK, but this usage did work in the past: that it now doesn't is a >> regression. GCC was quite useful (unique, really) in that it provided >> a way to write a decent bytecode interpreter in a HLL. The world has >> lost something significant if this no longer works. > > It still works, but again, it's not a guarantee, never has been.
I hear you, but what always mattered most was what happened in practice, and in practice it worked rather nicely. The question, then, isn't what we can guarantee but what usually works. And as we know, the behaviour of GCC isn't driven by the whim of the maintainers but by the needs of our users, especially kernel programmers! Authors of interpreters don't have quite so much influence. Andrew.
