On Thu, Jan 19, 2012 at 3:13 AM, Richard Guenther <richard.guent...@gmail.com> wrote: > On Thu, Jan 19, 2012 at 10:00 AM, Andrew Pinski > <andrew.pin...@caviumnetworks.com> wrote: >> On Tue, Jan 17, 2012 at 1:38 AM, Richard Guenther >> <richard.guent...@gmail.com> wrote: >>> On Tue, Jan 17, 2012 at 8:06 AM, Andrew Pinski >>> <andrew.pin...@caviumnetworks.com> wrote: >>>> Hi, >>>> This adds the folding of x & ((~x) | y)) into x & y on the tree >>>> level via fold-const.c >>>> There is already partly done on the RTL level but it would be a good >>>> thing for the tree level also. >>>> >>>> >>>> OK for 4.8 (yes I know we have not branched yet but I thought I would >>>> send it out so I don't forget about it)? >>>> Bootstrapped and tested on x86_64-linux-gnu with no regressions. >>> >>> Can you instead patch tree-ssa-forwprop.c:simplify_bitwise_binary? >> >> Yes and here is a new patch which also adds optimizing x | ((~x) & y)) to x >> | y. >> Also it adds the optimizing x & (x | y) to x and x | (x & y) to x to >> tree-ssa-forwprop.c:simplify_bitwise_binary >> since it was an easy extension on top of the ~x case (well I >> implemented the one without the ~ first). I did not remove those >> folding from fold-const.c though. >> >> Also I was thinking maybe this belongs in reassociate though I don't >> see how to do it. > > I still have plans to create that piecewise gimple_fold (see my proposal > from early last year) that would be the container for this kind of pattern > matching. It would then be usable from reassoc as well (but reassoc > has the issue of only collecting one kind of op, so its simplification > wouldn't trigger reliably on these). > > http://gcc.gnu.org/ml/gcc-patches/2011-03/msg01099.html > >> OK for 4.8, once in stage 1? Again bootstrapped and tested on >> x86_64-linux-gnu with no regressions. > > Ok.
Here is an updated patch which fixes a bug which I found while doing the treecombine branch. I rewrote defcodefor_name so more than SSA_NAMEs can be passed to it. OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. Thanks, Andrew Pinski ChangeLog: ChangeLog: * tree-ssa-forwprop.c (defcodefor_name): New function. (simplify_bitwise_binary): Use defcodefor_name instead of manually Simplify "( X | Y) & X" to X and "( X & Y) | X" to X. Simplify "(~X | Y) & X" to "X & Y" and "(~X & Y) | X" to "X | Y". testsuite/ChangeLog: * gcc.dg/tree-ssa/andor-3.c: New testcase. * gcc.dg/tree-ssa/andor-4.c: New testcase. * gcc.dg/tree-ssa/andor-5.c: New testcase. > > Thanks, > Richard. > >> Thanks, >> Andrew Pinski >> >> ChangeLog: >> * tree-ssa-forwprop.c (defcodefor_name): New function. >> (simplify_bitwise_binary): Use defcodefor_name. >> Simplify "( X | Y) & X" to X and "( X & Y) | X" to X. >> Simplify "(~X | Y) & X" to "X & Y" and >> "(~X & Y) | X" to "X | Y". >> >> testsuite/ChangeLog: >> * gcc.dg/tree-ssa/andor-3.c: New testcase. >> * gcc.dg/tree-ssa/andor-4.c: New testcase. >> * gcc.dg/tree-ssa/andor-5.c: New testcase. >> >> >>> >>> Thanks, >>> Richard. >>> >>>> Thanks, >>>> Andrew Pinski >>>> >>>> ChangeLog: >>>> * fold-const.c (fold_binary_loc <case BIT_AND_EXPR>): Add folding of x >>>> & (~x | y) into x & y. >>>> >>>> testsuite/ChangeLog: >>>> * gcc.dg/tree-ssa/andor-3.c: New testcase.
