On Mon, Nov 06, 2017 at 09:10:23AM +0000, Richard Sandiford wrote: > The recent gen_vec_duplicate patches used CONST_VECTOR for all > constants, but the documentation says: > > @findex const_vector > @item (const_vector:@var{m} [@var{x0} @var{x1} @dots{}]) > Represents a vector constant. The square brackets stand for the vector > containing the constant elements. @var{x0}, @var{x1} and so on are > the @code{const_int}, @code{const_double} or @code{const_fixed} elements. > > Both the AArch32 and AArch64 ports relied on the elements having > this form and would ICE if the element was something like a CONST > instead. This showed up as a failure in vect-102.c for both arm-eabi > and aarch64-elf (but not aarch64-linux-gnu, which is what the series > was tested on). > > The two obvious options were to redefine CONST_VECTOR to accept all > constants or make gen_vec_duplicate honour the existing documentation. > It looks like other code also assumes that integer CONST_VECTORs contain > CONST_INTs, so the patch does the latter. > > I deliberately didn't add an assert to gen_const_vec_duplicate > because it looks like the SPU port *does* expect to be able to create > CONST_VECTORs of symbolic constants. > > Also, I think the list above should include const_wide_int for vectors > of TImode and wider. > > The new routine takes a mode for consistency with the generators, > and because I think it does make sense to accept all constants for > variable-length: > > (const (vec_duplicate ...)) > > rather than have some rtxes for which we instead use: > > (vec_duplicate (const ...)) > > Tested on aarch64-elf, aarch64-linux-gnu, x86_64-linux-gnu and > powerpc64-linux-gnu. OK to install?
For what it is worth, I can see why this would fix the bug in the AArch64 port, and the patch looks good to me (though I can't approve it). > (but not aarch64-linux-gnu, which is what the series was tested on). Presumably it would fail there for -mcmodel=tiny too, we just don't run that variant by default. Thanks, James > 2017-11-06 Richard Sandiford <richard.sandif...@linaro.org> > > gcc/ > * doc/rtl.texi (const_vector): Say that elements can be > const_wide_ints too. > * emit-rtl.h (valid_for_const_vec_duplicate_p): Declare. > * emit-rtl.c (valid_for_const_vec_duplicate_p): New function. > (gen_vec_duplicate): Use it instead of CONSTANT_P. > * optabs.c (expand_vector_broadcast): Likewise.