On Tue, 29 Mar 2011 11:45:58 +0100 Richard Sandiford <richard.sandif...@linaro.org> wrote:
> Julian Brown <jul...@codesourcery.com> writes: > > On Thu, 24 Mar 2011 10:57:06 +0000 > > Richard Sandiford <richard.sandif...@linaro.org> wrote: > > > >> Chung-Lin Tang <clt...@codesourcery.com> writes: > >> > PR48183 is a case where ARM NEON instrinsics, under -O -g, > >> > produce debug insns that tries to expand OImode (32-byte > >> > integer) zero constants, much too large to represent as two > >> > HOST_WIDE_INTs; as the internals manual indicates, such large > >> > constants are not supported in general, and ICEs on the > >> > GET_MODE_BITSIZE(mode) == 2*HOST_BITS_PER_WIDE_INT assertion. > >> > > >> > This patch allows the cases where the large integer constant is > >> > still representable using a single CONST_INT, such as zero(0). > >> > Bootstrapped and tested on i686 and x86_64, cross-tested on ARM, > >> > all without regressions. Okay for trunk? > >> > > >> > Thanks, > >> > Chung-Lin > >> > > >> > 2011-03-20 Chung-Lin Tang <clt...@codesourcery.com> > >> > > >> > * emit-rtl.c (immed_double_const): Allow wider than > >> > 2*HOST_BITS_PER_WIDE_INT mode constants when they are > >> > representable as a single const_int RTX. > >> > >> I realise this might be seen as a good expedient fix, but it makes > >> me a bit uneasy. Not a very constructive rationale, sorry. > > > > FWIW I also had a "fix" for this issue, which is equivalent to > > Chung-Lin's patch apart from only allowing constant-zero (attached). > > That's not really a vote from me for this approach, but maybe > > limiting the extent to which we pretend to support wide-integer > > constants like this is sensible, if we do go that way. > > So that each suggestion has a patch, here's mine. I've snipped the > regenerated file from the testcase, but to get a flavour, the changes > are like this: The O'Caml changes look fine, FWIW (I can't officially approve them, of course) -- and I certainly don't have a problem with avoiding my or Chung-Lin's hacks, though of course it'd be nice to get rid of the wide-integer constant "problem" properly at some point. Cheers, Julian
