[llvm-dev] How to find the root causes of compiler bugs in practice?

[Richard Kenner via llvm-dev]

> Recently, I read two papers [1], [2] about finding the root causes
> of compiler bugs. However, I do not find any information in these
> paper about how compiler developers find the root causes of compiler
> bugs in practice. So I am curious whether these techniques are
> useful in practice. For my experience, the outputs of compilers are
> always used to isolate the causes of compiler bugs, such as the IR
> after each pass or the backtrace.

I'm not sure I understand what you're asking.  Once you know what a
compiler is doing wrong, you find the "root cause" of that going wrong
in the same way as you'd debug any other program.  Or are you asking
how compiler developers determine what's causing a compiler issue?