Re: [PATCH] lra: Tighten check for reloading paradoxical subregs [PR94052]

2020-03-20 Thread Vladimir Makarov via Gcc-patches
On 2020-03-20 1:19 p.m., Richard Sandiford wrote: Ping Richard, sorry.  I missed your original message. Richard Sandiford writes: [See: https://gcc.gnu.org/pipermail/gcc-patches/2020-March/541694.html https://gcc.gnu.org/pipermail/gcc-patches/2020-March/541759.html for a walkthrough

Re: [PATCH] lra: Tighten check for reloading paradoxical subregs [PR94052]

2020-03-20 Thread Richard Sandiford
Ping Richard Sandiford writes: > [See: > > https://gcc.gnu.org/pipermail/gcc-patches/2020-March/541694.html > https://gcc.gnu.org/pipermail/gcc-patches/2020-March/541759.html > > for a walkthrough of what goes wrong in the testcase, but hopefully > the change makes sense on first principles.]

Re: [PATCH] lra: Tighten check for reloading paradoxical subregs [PR94052]

2020-03-13 Thread Richard Sandiford
Eric Botcazou writes: >> I think there are two problems with this: >> >> (1) It never actually checks whether the hard register is valid for the >> outer mode (in the hard_regno_mode_ok sense). If it isn't, any attempt >> to reload in the outer mode is likely to cycle, because the implie

Re: [PATCH] lra: Tighten check for reloading paradoxical subregs [PR94052]

2020-03-13 Thread Eric Botcazou
> I think there are two problems with this: > > (1) It never actually checks whether the hard register is valid for the > outer mode (in the hard_regno_mode_ok sense). If it isn't, any attempt > to reload in the outer mode is likely to cycle, because the implied > regno/mode combinati