Re: Issue in combine pass.

[Paolo Bonzini <bonzini at gnu dot org>]

On 03/25/2010 12:31 PM, Eric Botcazou wrote:
> The combine pass had been written at least a decade before vector modes were
> introduced so it essentially doesn't expect them, i.e. some transformations
> simply don't make sense for vector modes.  You need to analyze the one you're
> seeing (e.g. where does the subreg come from?) and determine whether it makes
> sense; it it doesn't, then it should be disabled for vector modes.

The whole of simplify_shift_const probably doesn't make sense.  Other 
likely candidates are simplify_and_const_int and force_to_mode, though 
there may be something to salvage there.

Paolo