Re: PR 19893 & array_ref bug

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Mark Mitchell <mark@codesourcery.com> writes:

| Steve Ellcey wrote:
| > What do people think about this idea for changing the vect tests using
| > gcc.dg/vect/vect-56.c as an example.  The arguments (pa, pb, pc) would
| > remain afloat type (vs. float) but the arrays would be changed from
| > 'array of aligned floats' to an array of floats where the actual array
| > itself is aligned.
| 
| That makes sense to me.

Seconded.

|  (Independently of whether or not we continue
| to allow the brokenness currently in GCC, there is no reason to
| actively make use of it.)

I believe we should consider correcting that bug.

| > It seems like we are lying about the alignment of the pa, pb, pc
| > arguments but I don't see a way around this.
| 
| Make them array arguments, instead of pointer arguments.  I'm not sure
| if GCC is smart enough to still vectorize them in that case, but
| that's the right way to express it.  An aligned array-of-floats decays
| to an aligned pointer-to-float, i.e., the pointer is known to be
| aligned, but the object pointed to is just a float not an aligned
| float.

Agreed.

-- Gaby