define_split

[Joern Rennecke]

Quoting Paolo Bonzini <bonzini@gnu.org>:

> On 11/09/2010 05:38 PM, Joern Rennecke wrote:
>> A define_insn will be recognized in all contexts.
>> Having an insn pattern for an insn that does not actually exist can cause
>> all kinds of unintended consequences as the optimizers try to generate
>> and recognize 'optimized' patterns, or when reload does its stuff.
>
> Before reload that is not a problem at all, I think, actually it can be
> an advantage.

No, it is a code quality problem.  And yes, I have seen actual
SH patterns being recognized that were not wanted, and lead to worse
code overall.