On Mon, Dec 29, 2014 at 5:30 AM, Yuri Rumyantsev <ysrum...@gmail.com> wrote: > Hi All, > > Here is a patch which fixed several performance degradation after > operand canonicalization (r216728). Very simple approach is used - if > operation is commutative and its second operand required more > operations (statements) for computation, swap operands. > Currently this is done under special option which is set-up to true > only for x86 32-bit targets ( we have not seen any performance > improvements on 64-bit).
Can you open a regression bug? Do you know how it improves performance in 32-bit? > Is it OK for trunk? > > 2014-12-26 Yuri Rumyantsev <ysrum...@gmail.com> > > * cfgexpand.c (count_num_stmt): New function. > (reorder_operands): Likewise. > (expand_gimple_basic_block): Insert call of reorder_operands. > * common.opt(flag_reorder_operands): Add new flag. > * config/i386/i386.c (ix86_option_override_internal): Add setup of > flag_reorder_operands for 32-bit target only. > * (doc/invoke.texi: Add new optimization option -freorder-operands. > > gcc/testsuite/ChangeLog > * gcc.target/i386/swap_opnd.c: New test. -- H.J.
