Ilya Leoshkevich <i...@linux.ibm.com> writes: > On S/390 there is a need to support more than 32 instruction > alternatives per define_insn. Currently this is not explicitly > prohibited or unsupported: MAX_RECOG_ALTERNATIVES is equal 35, and, > futhermore, the related code uses uint64_t for bitmaps in most places. > > However, genattrtab contains the logic to convert (eq_attr "attribute" > "value") RTXs to (eq_attr_alt bitmap) RTXs, where bitmap contains > alternatives, whose "attribute" has the corresponding "value". > Unfortunately, bitmap is only 32 bits. > > When adding the 33rd alternative, this led to (eq_attr "type" "larl") > becoming (eq_attr_alt -1050625 1), where -1050625 == 0xffeff7ff. The > cleared bits 12, 21 and 32 correspond to two existing and one newly > added insn of type "larl". compute_alternative_mask sign extended this > to 0xffffffffffeff7ff, which contained non-existent alternatives, and > this made simplify_test_exp fail with "invalid alternative specified". > > I'm not sure why it didn't fail the same way before, since the top bit, > which led to sign extension, should have been set even with 32 > alternatives. Maybe simplify_test_exp was not called for "type" > attribute for some reason? > > This patch widens EQ_ATTR_ALT bitmap to 64 bits, making it possible to > gracefully handle up to 64 alternatives. It eliminates the problem with > the 33rd alternative on S/390.
Could you test this with --enable-checking=yes,rtl , if you haven't already, to check that there are no mossing XINT->XWINT changes? OK if that passes, thanks. Richard
