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). > > 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.
