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*From*: Richard Guenther <richard dot guenther at gmail dot com>*To*: Andrew Pinski <andrew dot pinski at caviumnetworks dot com>*Cc*: GCC Patches <gcc-patches at gcc dot gnu dot org>*Date*: Mon, 23 Apr 2012 11:41:55 +0200*Subject*: Re: [PATCH] Fix PR 33512 Folding of x & ((~x) | y) into x & y on the tree level*References*: <CA+=Sn1kFkikJcCvjCk7W2e=ne06vM9yoBwfmr5u2oFesUBT7-A@mail.gmail.com> <CAFiYyc39Jo1a-M_CQJZx--hE6BU_A2g+sx_6KVs-XjgroOq7wA@mail.gmail.com> <CA+=Sn1kB41c2bh5LxvmQUn0TTH6aSXTaK9KoTormoAX+HKXYrg@mail.gmail.com> <CAFiYyc1WQumUjg8MFvzLkNYhXOKZydERPo6vwmMnHSy7S_gG8Q@mail.gmail.com> <CA+=Sn1kDcF+Mau9ftau0f5P70Gff0FE3LGv7maigHPvdjAvDYA@mail.gmail.com> <CA+=Sn1n_KTBX9CPF2eR_GCovpuZYPHxtC7kgmCwcdBMGQmW1MQ@mail.gmail.com>

On Sat, Apr 21, 2012 at 6:06 AM, Andrew Pinski <andrew.pinski@caviumnetworks.com> wrote: > This time with the patch and describing what the bug was. ?The problem > was defcodefor_name does not always set arg1 and arg2. ?This fixes it > so it is always set to NULL if they don't exist. Ok with ... + if (code1 == SSA_NAME) + { + def = SSA_NAME_DEF_STMT (name); + + if (def && is_gimple_assign (def) + && can_propagate_from (def)) + { + code1 = gimple_assign_rhs_code (def); + arg11 = gimple_assign_rhs1 (def); + arg21 = gimple_assign_rhs2 (def); + arg31 = gimple_assign_rhs2 (def); + } + } ... recursing here instead. Thanks, Richard. > Thanks, > Andrew > > On Fri, Apr 20, 2012 at 9:05 PM, Andrew Pinski > <andrew.pinski@caviumnetworks.com> wrote: >> On Thu, Jan 19, 2012 at 3:13 AM, Richard Guenther >> <richard.guenther@gmail.com> wrote: >>> On Thu, Jan 19, 2012 at 10:00 AM, Andrew Pinski >>> <andrew.pinski@caviumnetworks.com> wrote: >>>> On Tue, Jan 17, 2012 at 1:38 AM, Richard Guenther >>>> <richard.guenther@gmail.com> wrote: >>>>> On Tue, Jan 17, 2012 at 8:06 AM, Andrew Pinski >>>>> <andrew.pinski@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.

**Follow-Ups**:**Re: [PATCH] Fix PR 33512 Folding of x & ((~x) | y) into x & y on the tree level***From:*Andrew Pinski

**References**:**Re: [PATCH] Fix PR 33512 Folding of x & ((~x) | y) into x & y on the tree level***From:*Andrew Pinski

**Re: [PATCH] Fix PR 33512 Folding of x & ((~x) | y) into x & y on the tree level***From:*Andrew Pinski

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