On Fri, Feb 19, 2016 at 10:24 PM, Jeff Law <l...@redhat.com> wrote: > On 02/16/2016 11:43 AM, Bin Cheng wrote: >> >> ________________________________________ >> From: Jeff Law <l...@redhat.com> >> Sent: 11 February 2016 23:26 >> To: Bin.Cheng >> Cc: Bin Cheng; gcc-patches@gcc.gnu.org; nd >> Subject: Re: [PATCH PR69052]Check if loop inv can be propagated into mem >> ref with additional addr expr canonicalization >> >>>> On 02/11/2016 10:59 AM, Bin.Cheng wrote: >> >> >>>> Hi Jeff, >>>> Thanks for detailed review. I also think a generic canonical >>>> interface for RTL is much better. I will give it a try. But with >>>> high chance it's a next stage1 stuff. >>> >>> That is, of course, fine. However, if you do get something ready, I'd >>> support using it within LICM for gcc-6, then using it in other places >>> for gcc-7. >> >> Hi, >> This is the updated version patch. It fixes the problem by introducing a >> generic address canonicalization interface. This new interface >> canonicalizes address expression in following steps: >> 1) Rewrite ASHIFT into MULT recursively. >> 2) Divide address into sub expressions with PLUS as the separator. >> 3) Sort sub expressions according to precedence defined for >> communative operations. >> 4) Simplify CONST_INT_P sub expressions. >> 5) Create new canonicalized address and return. >> >> According to review comments, this interface is now restricted in LCIM, >> and will probably be expanded to other passes like fwprop and combine after >> entering GCC7. >> Bootstrap and test on x86_64 and AArch64. Is it OK? >> >> Thanks, >> bin >> >> 2016-02-15 Bin Cheng <bin.ch...@arm.com> >> >> PR tree-optimization/69052 >> * loop-invariant.c (canonicalize_address_mult): New function. >> (MAX_CANON_ADDR_PARTS): New macro. >> (collect_address_parts): New function. >> (compare_address_parts, canonicalize_address): New functions. >> (inv_can_prop_to_addr_use): Check validity of address expression >> which is canonicalized by above canonicalize_address. >> >> gcc/testsuite/ChangeLog >> 2016-02-15 Bin Cheng <bin.ch...@arm.com> >> >> PR tree-optimization/69052 >> * gcc.target/i386/pr69052.c: New test. > > This is exactly what I was looking for from a design standpoint. > > My only question is why didn't you use FOR_EACH_SUBRTX_VRA from rtl-iter.h > to walk the RTX expressions in collect_address_parts and > canonicalize_address_mult? Hi Jeff, Nothing special, just I haven't used this before, also canonicalize_address_mult is alphabetically copied from fwprop.c. One question is when rewriting SHIFT to MULT, we need to modify rtl expression in place, does FOR_EACH_SUBRTX iterator support this? If yes, what is the behavior for modified sub-expression?
Thanks, bin > > Jeff > > >> >>> >>> Jeff >> >> >
