[Bug rtl-optimization/69447] [5/6 Regression] wrong code with -O2 -fno-schedule-insns and mixed 8/16/32/64bit arithmetics @ armv7a

[rth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69447

--- Comment #13 from Richard Henderson <rth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #11)
> Without knowing the lra-remat code at all, I just wonder if subreg_regs
> needs to be one per the whole function, rather than say per extended basic
> block or basic block, with the patch any uses in multi-reg subregs anywhere
> in the function will affect remat of all other spots where it is used.

I started with subreg_regs being per-block.  But since IRA has
some global component, I was concerned that there would be some
edge case that would be missed, and switched to a global bitmap.

Perhaps someone who knows the allocator better can comment.