This probably/obviously isn't the best place for this discussion, but... At Mon, 25 May 2026 00:02:17 +0000, David Holland <dholland-tech%netbsd.org@localhost> wrote: Subject: Re: netbsd-11 gcc bug > > The places where > certain bits of undefined and unspecified behavior line up exactly > with things that mattered in a compiler written forty years ago are no > longer obvious, and so what's left is a vague general belief that the > UB in the C standard is meant to be room for optimizers. The reason for the "belief" that UB is (often) related to optimizers is squarely resting on the fact that when the optimizer is turned off then the UB goes away. So it's not really a belief -- it's a demonstrable fact! That and the fact some of the compiler maintainers influencing the standard have basically said that they explicitly rely on some UB conditions to allow their optimization tricks to work. So it's very difficult to separate many of the current cases of UB from some aspect of optimization. > You can try pushing back, but you aren't going to get anywhere. As I said, efforts to eliminate UB from C are actually happening at the standards committee level, so.... -- Greg A. Woods <gwoods%acm.org@localhost> Kelowna, BC +1 250 762-7675 RoboHack <woods%robohack.ca@localhost> Planix, Inc. <woods%planix.com@localhost> Avoncote Farms <woods%avoncote.ca@localhost>
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