On Thu, Nov 24, 2016 at 10:14:24AM -0600, Segher Boessenkool wrote: > On Thu, Nov 24, 2016 at 08:48:04AM -0700, Jeff Law wrote: > > On 11/24/2016 07:53 AM, Segher Boessenkool wrote: > > > > > >That we compare different kinds of costs (which really has no meaning at > > >all, it's a heuristic at best) in various places is a known problem, not > > >a regression. > > But the problems with the costing system exhibit themselves as a code > > quality regression. In the end that's what the end-users see -- a > > regression in the quality of the code GCC generates. > > Yes, exactly -- and I fear this all-encompassing change will cause just > such a regression for many users. Tests are running, will know more > later today (or tomorrow). > > The PR is about a very specific problem; the patch is not. The patch > is not a bug fix. If we allow anything that "makes things better" in > stage 3, what make it different from stage 1 then?
Here are results of testing with trunk right before the three patches, compared with with the three patches. This lists the sizes of the vmlinux of a Linux kernel build for that arch. better: blackfin 1973931 1973867 frv 3638192 3637792 h8300 1060172 1059976 i386 9742984 9742463 ia64 15402035 15396171 mips 4286748 4286692 mn10300 2360025 2358201 nios2 3185625 3176693 x86_64 10360418 10359588 worse: alpha 5439003 5455979 c6x 2107939 2108931 cris 2189380 2193836 m32r 3427409 3427453 m68k 3228408 3230978 mips64 5564819 5565291 parisc 8278881 8289573 parisc64 7234619 7249139 powerpc 8438949 8440005 powerpc64 14499969 14508689 s390 12778748 12779220 shnommu 1369868 1371020 sparc64 5921556 5922172 tilegx 12297581 12307461 tilepro 11215603 11227339 xtensa 1776196 1779152 does not build: arc 0 0 arm 0 0 arm64 0 0 microblaze 0 0 sh 0 0 sparc 0 0 Segher