On Tue, Sep 15, 2015 at 7:57 AM, Bin.Cheng <amker.ch...@gmail.com> wrote: > Ping.
Ok. Thanks, Richard. > On Thu, Aug 27, 2015 at 5:41 PM, Bin Cheng <bin.ch...@arm.com> wrote: >> Hi, >> This is a rework for >> https://gcc.gnu.org/ml/gcc-patches/2015-07/msg02335.html, with review >> comments addressed. For now, SCEV may compute iv base in the form of >> "(signed T)((unsigned T)base + step))". This complicates other >> optimizations/analysis depending on SCEV because it's hard to dive into type >> conversions. This kind of type conversions can be simplified with >> additional range information implied by loop initial conditions. This patch >> does such simplification. >> With simplified iv base, loop niter analysis can compute more accurate bound >> information since sensible value range can be derived for "base+step". For >> example, accurate loop bound&may_be_zero information is computed for cases >> added by this patch. >> >> The code is actually moved from loop_exits_before_overflow. After this >> patch, the corresponding code in loop_exits_before_overflow will be never >> executed, so I removed that part code. The patch also includes some code >> format changes. >> >> Bootstrap and test on x86_64. Is it OK? >> >> Thanks, >> bin >> >> 2015-08-27 Bin Cheng <bin.ch...@arm.com> >> >> * tree-ssa-loop-niter.c (tree_simplify_using_condition_1): Support >> new parameter. >> (tree_simplify_using_condition): Ditto. >> (simplify_using_initial_conditions): Ditto. >> (loop_exits_before_overflow): Pass new argument to function >> simplify_using_initial_conditions. Remove case for type conversions >> simplification. >> * tree-ssa-loop-niter.h (simplify_using_initial_conditions): New >> parameter. >> * tree-scalar-evolution.c (simple_iv): Simplify type conversions >> in iv base using loop initial conditions. >> >> gcc/testsuite/ChangeLog >> 2015-08-27 Bin Cheng <bin.ch...@arm.com> >> >> * gcc.dg/tree-ssa/loop-bound-2.c: New test. >> * gcc.dg/tree-ssa/loop-bound-4.c: New test. >> * gcc.dg/tree-ssa/loop-bound-6.c: New test.
