On Thu, Oct 17, 2013 at 6:39 PM, Andrew Pinski <pins...@gmail.com> wrote: > On Thu, Oct 17, 2013 at 4:03 AM, Richard Biener > <richard.guent...@gmail.com> wrote: >> On Thu, Oct 17, 2013 at 4:14 AM, Andrew Pinski <pins...@gmail.com> wrote: >>> On Wed, Oct 16, 2013 at 2:12 AM, Zhenqiang Chen >>> <zhenqiang.c...@linaro.org> wrote: >>>> Hi, >>>> >>>> The patch enhances ifcombine pass to recover some non short circuit >>>> branches. Basically, it will do the following transformation: >>>> >>>> Case 1: >>>> if (cond1) >>>> if (cond2) >>>> ==> >>>> if (cond1 && cond2) >>>> >>>> Case 2: >>>> if (cond1) >>>> goto L1 >>>> if (cond2) >>>> goto L1 >>>> ==> >>>> if (cond1 || cond2) >>>> goto L1 >>>> >>>> Case 3: >>>> if (cond1) >>>> goto L1 >>>> else >>>> goto L2 >>>> L1: >>>> if (cond2) >>>> goto L2 >>>> ==> >>>> if (invert (cond1) || cond2) >>>> goto L2 >>>> >>>> Case 4: >>>> if (cond1) >>>> goto L1 >>>> if (cond2) >>>> goto L2 >>>> L1: >>>> ==> >>>> if (invert (cond1) && cond2) >>>> goto L2 >>>> >>>> Bootstrap on X86-64 and ARM. >>>> >>>> Two new FAILs in regression tests: >>>> gcc.dg/uninit-pred-8_b.c >>>> gcc.dg/uninit-pred-9_b.c >>>> uninit pass should be enhanced to handle more complex conditions. Will >>>> submit a bug to track it and fix it later. >>>> >>>> Is it OK for trunk? >>> >>> I had a much simpler change which did basically the same from 4.7 (I >>> can update it if people think this is a better approach). >> >> I like that more (note you can now use is_gimple_condexpr as predicate >> for force_gimple_operand). > > > Ok, with both this email and Jakub's email, I decided to port the > patch to the trunk but I ran into a bug in reassoc which I submitted > as PR 58775 (with a testcase which shows the issue without this > patch).
I forgot to say that the tree-ssa-ifcombine.c hunk of the 4.7 patch applies correctly. Once PR 58775 is fixed, I will be testing and submitting the full patch including with the testcases from Zhenqiang. Thanks, Andrew > > >> >> With that we should be able to kill the fold-const.c transform? > > > I think so but I have never tested removing it. > > Thanks, > Andrew Pinski > > >> >> Thanks, >> Richard. >> >>> Thanks, >>> Andrew Pinski >>> >>> >>> 2012-09-29 Andrew Pinski <apin...@cavium.com> >>> >>> * tree-ssa-ifcombine.c: Include rtl.h and tm_p.h. >>> (ifcombine_ifandif): Handle cases where >>> maybe_fold_and_comparisons fails, combining the branches >>> anyways. >>> (tree_ssa_ifcombine): Inverse the order of >>> the basic block walk, increases the number of combinings. >>> * Makefile.in (tree-ssa-ifcombine.o): Update dependencies. >>> >>> * testsuite/gcc.dg/tree-ssa/phi-opt-2.c: Expect zero ifs as the >>> compiler >>> produces a & b now. >>> * testsuite/gcc.dg/tree-ssa/phi-opt-9.c: Use a function call >>> to prevent conditional move to be used. >>> * testsuite/gcc.dg/tree-ssa/ssa-dom-thread-3.c: Remove check for >>> "one or more intermediate". >>> >>> >>>> >>>> Thanks! >>>> -Zhenqiang >>>> >>>> ChangeLog: >>>> 2013-10-16 Zhenqiang Chen <zhenqiang.c...@linaro.org> >>>> >>>> * fold-const.c (simple_operand_p_2): Make it global. >>>> * tree.h (simple_operand_p_2): Declare it. >>>> * tree-ssa-ifcombine.c: Include rtl.h and tm_p.h. >>>> (bb_has_overhead_p, generate_condition_node, >>>> ifcombine_ccmp): New functions. >>>> (ifcombine_fold_ifandif): New function, extracted from >>>> ifcombine_ifandif. >>>> (ifcombine_ifandif): Call ifcombine_ccmp. >>>> (tree_ssa_ifcombine_bb): Skip optimized bb. >>>> >>>> testsuite/ChangeLog >>>> 2013-10-16 Zhenqiang Chen <zhenqiang.c...@linaro.org> >>>> >>>> * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-1.c: New test case. >>>> * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-2.c: New test case. >>>> * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-3.c: New test case. >>>> * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-4.c: New test case. >>>> * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-5.c: New test case. >>>> * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-6.c: New test case. >>>> * gcc.dg/tree-ssa/ssa-dom-thread-3.c: Updated.
