Re: armv7 lang/gcc12 "no bootstrap" build via system clang 15.0.7 based poudriere build ends up stuck in a small loop

On 7 Mar 2023, at 11:26, Mark Millard <marklmi@yahoo.com> wrote:
> 
> Below is a small example C source showing the clang 15+ armv7
> problem that leads to the unbounded looping in later code in
> the lang/gcc12+ builds: a data structure is mis-initialized,
> breaking its invariant properties used by the later code
> structure.
...
> In the output below, note the blocks of 4 "next"
> values that do not change. Each should match the
> earlier hexadecimal value on the same line: point
> back to same element of the array. 3 of 4 do not.
> 
> # cc -g -O2 partition.c
> # ./a.out
> 0: 0x40a84 : next?: 0x40a84
> 1: 0x40a90 : next?: 0x40a84
> 2: 0x40a9c : next?: 0x40a84
> 3: 0x40aa8 : next?: 0x40a84

Very strange, I don't see this at all here. All the values are always
correct, at every optimization level. I tried clang 13, clang 14, clang
15 from base and clang 15 from ports. However, my architecture is amd64,
so maybe you are running into a armv7 specific issue?

-Dimitry