It's been a month. Ping! I disabled late-combine for CRIS, so to expose the bug for current master, you'll need to enable that pass explicitly when testing, e.g like "make -k check-gcc-c RUNTESTFLAGS=--target_board=cris-sim/-flate-combine-instructions\ cris.exp=rld-legit2.c"
I verified that the patch still works around the issue at r15-2881-g4bcb480d103b. brgds, H-P > From: Hans-Peter Nilsson <h...@axis.com> > Date: Fri, 12 Jul 2024 03:17:39 +0200 > > CC to both the combine maintainer and the RA maintainer for > verdict on whether this is the true correction or just a > "fix"; whether REG_POINTER must be present or is just an > optimization hint. And I almost forgot, the late-combine > author! At least I hope to clarify the commit log based on > your replies. Please also see PR115883. > > Tested cris-elf, where the ICEs are gone. Test-results need another > patch to be restored ante late-combine, though. Also regtested native > x86_64-pc-linux-gnu. > > Ok to commit? > > -- >8 -- > The first of the late-combine passes, propagates some of the copies > made during the (in-time-)combine pass in make_more_copies into the > users of the "original" pseudo registers and removes the "old" > pseudos. That effectively removes attributes such as REG_POINTER, > which matter to LRA. I *think* the actual bug causing the ICEs in the > PR is in LRA. Either that, or this is the actual bug and REG_POINTER > *must* be present for registers used to form base addresses going into > IRA and LRA. But the documentation doesn't support that claim, > AFAICS. > > Anyway, this patch corrects state for those propagated uses to ante > late-combine. > > PR middle-end/115883 > * combine.cc (make_more_copies): Copy attributes from the original > pseudo to the new copy. > --- > gcc/combine.cc | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/gcc/combine.cc b/gcc/combine.cc > index 3b50bc3529c4..6e6e710aae08 100644 > --- a/gcc/combine.cc > +++ b/gcc/combine.cc > @@ -15102,6 +15102,12 @@ make_more_copies (void) > continue; > > rtx new_reg = gen_reg_rtx (GET_MODE (dest)); > + > + // The "original" pseudo copies have important attributes > + // attached, like pointerness. We want that for these copies > + // too, for use by insn recognition and later passes. > + set_reg_attrs_from_value (new_reg, dest); > + > rtx_insn *new_insn = gen_move_insn (new_reg, src); > SET_SRC (set) = new_reg; > emit_insn_before (new_insn, insn); > -- > 2.30.2 >
