On 10/28/22 03:17, Richard Biener wrote:
On Wed, Oct 26, 2022 at 4:24 PM Andrew MacLeod <amacl...@redhat.com> wrote:
Figured I would ask what you guys think of making ranger the default for
the VRP1 pass now.
With partial equivalences and the other bits I checked in the past few
weeks I'm not aware of much that the legacy VRP pass gets that ranger
doesn't. The only exception to that which I am aware of is the trick
played with the unreachable edges to set global ranges, but that is done
in the DOM passes now anyway... so it just happens slightly later in the
optimization cycle.
Note DOM should go away at some point. Why can this not happen during
ranger driven VRP?
I have been working on that for the last 2 days. Turns out VRP1 can
remove builtin_unreachable from the
if (X)
__builtin_unreachable ()
idiom and set the appropriate global ranges, but it has to leave those
with 2 ssa-names:
if (a_1 != b_2)
__builtin_unreachable()
until the second pass of VRP or we lose the relationship between a_1 and
b_2. That triggers some failures. Specifically a vectorizor fail
because it cant be sure that the start and end point are not the same
without the condition in the IL. Trying to store global relations over
multiple passes would be problematic at this stage of development, so I
don't see a problem with leaving it that way.
bultin_unreachables() from switches get removed during the second pass
of switch-conversion... which I presume remains OK.
Anyway, thats pretty much under control. Patch probably coming later today.
There is one test case that needs adjustment for
that which was just checking for a mask in DOM2
(gcc.dg/tree-ssa/pr107009.c). At this point I have not aware of
anything that Id be concerned about, and the testsuite seems to run
cleanly.
Did you enable Ada? The only feature I don't see implemented is
symbolic range handling which boils down to general base + constant offset
range endpoints (that's what symbolic ranges allow). That area was
specifically improved to optimize range checks emitted by the Ada frontend
but IIRC also applies to fortran -frange-check (not sure about test coverage
of that).
I get a clean testsuite run configured and bootstrapped with
--enable-languages=c,c++,go,fortran,ada,obj-c++,jit --enable-host-shared
Is there a PR or specific tests in either fortran or ada for those
improvements? ie, something specific I should check for? Part of rangers
point is to be able to do symbolic relationships without storing the
symbolic in the range, just picking it up from the IL as needed.
Andrew
