Jiufu Guo <guoji...@linux.ibm.com> writes: Hi!
I'd like to ping following patch. just in case it may make sense to include in GCC 10. Thanks! https://gcc.gnu.org/ml/gcc-patches/2020-02/msg00927.html Jiufu > Hi Honza and all, > > I updated the patch a little as below. Bootstrap and regtest are ok > on powerpc64le. > > Is OK for trunk? > > Thanks for comments. > Jiufu > > diff --git a/gcc/cfgloopmanip.c b/gcc/cfgloopmanip.c > index 727e951..ded0046 100644 > --- a/gcc/cfgloopmanip.c > +++ b/gcc/cfgloopmanip.c > @@ -31,6 +31,7 @@ along with GCC; see the file COPYING3. If not see > #include "gimplify-me.h" > #include "tree-ssa-loop-manip.h" > #include "dumpfile.h" > +#include "cfgrtl.h" > > static void copy_loops_to (class loop **, int, > class loop *); > @@ -1258,14 +1259,30 @@ duplicate_loop_to_header_edge (class loop *loop, edge > e, > /* If original loop is executed COUNT_IN times, the unrolled > loop will account SCALE_MAIN_DEN times. */ > scale_main = count_in.probability_in (scale_main_den); > + > + /* If we are guessing at the number of iterations and count_in > + becomes unrealistically small, reset probability. */ > + if (!(count_in.reliable_p () || loop->any_estimate)) > + { > + profile_count new_count_in = count_in.apply_probability > (scale_main); > + profile_count preheader_count = loop_preheader_edge (loop)->count > (); > + if (new_count_in.apply_scale (1, 10) < preheader_count) > + scale_main = profile_probability::likely (); > + } > + > scale_act = scale_main * prob_pass_main; > } > else > { > + profile_count new_loop_count; > profile_count preheader_count = e->count (); > - for (i = 0; i < ndupl; i++) > - scale_main = scale_main * scale_step[i]; > scale_act = preheader_count.probability_in (count_in); > + /* Compute final preheader count after peeling NDUPL copies. */ > + for (i = 0; i < ndupl; i++) > + preheader_count = preheader_count.apply_probability (scale_step[i]); > + /* Subtract out exit(s) from peeled copies. */ > + new_loop_count = count_in - (e->count () - preheader_count); > + scale_main = new_loop_count.probability_in (count_in); > } > } > > @@ -1381,6 +1398,38 @@ duplicate_loop_to_header_edge (class loop *loop, edge > e, > scale_bbs_frequencies (new_bbs, n, scale_act); > scale_act = scale_act * scale_step[j]; > } > + > + /* Need to update PROB of exit edge and corresponding COUNT. */ > + if (orig && is_latch && (!bitmap_bit_p (wont_exit, j + 1)) > + && bbs_to_scale) > + { > + edge new_exit = new_spec_edges[SE_ORIG]; > + profile_count new_count_in = new_exit->src->count; > + profile_count preheader_count = loop_preheader_edge (loop)->count (); > + edge e; > + edge_iterator ei; > + > + FOR_EACH_EDGE (e, ei, new_exit->src->succs) > + if (e != new_exit) > + break; > + > + gcc_assert (e && e != new_exit); > + > + new_exit->probability = preheader_count.probability_in (new_count_in); > + e->probability = new_exit->probability.invert (); > + > + profile_count new_latch_count > + = new_exit->src->count.apply_probability (e->probability); > + profile_count old_latch_count = e->dest->count; > + > + EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) > + scale_bbs_frequencies_profile_count (new_bbs + i, 1, > + new_latch_count, > + old_latch_count); > + > + if (current_ir_type () != IR_GIMPLE) > + update_br_prob_note (e->src); > + } > } > free (new_bbs); > free (orig_loops); > diff --git a/gcc/testsuite/gcc.dg/pr68212.c b/gcc/testsuite/gcc.dg/pr68212.c > new file mode 100644 > index 0000000..f3b7c22 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr68212.c > @@ -0,0 +1,13 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fno-tree-vectorize -funroll-loops --param > max-unroll-times=4 -fdump-rtl-alignments" } */ > + > +void foo(long int *a, long int *b, long int n) > +{ > + long int i; > + > + for (i = 0; i < n; i++) > + a[i] = *b; > +} > + > +/* { dg-final { scan-rtl-dump-times "internal loop alignment added" 1 > "alignments"} } */ > +
