Richard Biener <rguent...@suse.de> writes:
> This should be 4/4 but I have the main patch on top, so...
>
> This uses the region-based VN from GIMPLE unrolling which means
> we better approximate the effects optimizations on unrolled inner
> loops when evaluating whether to unroll outer ones.
Great! Sounds like it should also fix cases where missed value-numbering
opportunities after unrolling prevented SLP vectorisation. (Hit a few of
those, but don't have the testcases to hand unfortunately.)
Thanks,
Richard
>
> * tree-ssa-loop-ivcanon.c: Include tree-ssa-sccvn.h.
> (propagate_constants_for_unrolling): Remove.
> (tree_unroll_loops_completely): Perform value-numbering
> on the unrolled bodies loop parent.
>
> * gfortran.dg/reassoc_4.f: Change max-completely-peeled-insns
> param to current default.
> ---
> gcc/testsuite/gfortran.dg/reassoc_4.f | 2 +-
> gcc/tree-ssa-loop-ivcanon.c | 57
> ++++++-----------------------------
> 2 files changed, 10 insertions(+), 49 deletions(-)
>
> diff --git a/gcc/testsuite/gfortran.dg/reassoc_4.f
> b/gcc/testsuite/gfortran.dg/reassoc_4.f
> index b155cba768c..07b4affb2a4 100644
> --- a/gcc/testsuite/gfortran.dg/reassoc_4.f
> +++ b/gcc/testsuite/gfortran.dg/reassoc_4.f
> @@ -1,5 +1,5 @@
> ! { dg-do compile }
> -! { dg-options "-O3 -ffast-math -fdump-tree-reassoc1 --param
> max-completely-peeled-insns=400" }
> +! { dg-options "-O3 -ffast-math -fdump-tree-reassoc1 --param
> max-completely-peeled-insns=200" }
> ! { dg-additional-options "--param max-completely-peel-times=16" { target
> spu-*-* } }
> subroutine anisonl(w,vo,anisox,s,ii1,jj1,weight)
> integer ii1,jj1,i1,iii1,j1,jjj1,k1,l1,m1,n1
> diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
> index 326589f63c3..97c2ad94985 100644
> --- a/gcc/tree-ssa-loop-ivcanon.c
> +++ b/gcc/tree-ssa-loop-ivcanon.c
> @@ -63,6 +63,7 @@ along with GCC; see the file COPYING3. If not see
> #include "tree-inline.h"
> #include "tree-cfgcleanup.h"
> #include "builtins.h"
> +#include "tree-ssa-sccvn.h"
>
> /* Specifies types of loops that may be unrolled. */
>
> @@ -1318,50 +1319,6 @@ canonicalize_induction_variables (void)
> return 0;
> }
>
> -/* Propagate constant SSA_NAMEs defined in basic block BB. */
> -
> -static void
> -propagate_constants_for_unrolling (basic_block bb)
> -{
> - /* Look for degenerate PHI nodes with constant argument. */
> - for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
> - {
> - gphi *phi = gsi.phi ();
> - tree result = gimple_phi_result (phi);
> - tree arg = gimple_phi_arg_def (phi, 0);
> -
> - if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (result)
> - && gimple_phi_num_args (phi) == 1
> - && CONSTANT_CLASS_P (arg))
> - {
> - replace_uses_by (result, arg);
> - gsi_remove (&gsi, true);
> - release_ssa_name (result);
> - }
> - else
> - gsi_next (&gsi);
> - }
> -
> - /* Look for assignments to SSA names with constant RHS. */
> - for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
> - {
> - gimple *stmt = gsi_stmt (gsi);
> - tree lhs;
> -
> - if (is_gimple_assign (stmt)
> - && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_constant
> - && (lhs = gimple_assign_lhs (stmt), TREE_CODE (lhs) == SSA_NAME)
> - && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> - {
> - replace_uses_by (lhs, gimple_assign_rhs1 (stmt));
> - gsi_remove (&gsi, true);
> - release_ssa_name (lhs);
> - }
> - else
> - gsi_next (&gsi);
> - }
> -}
> -
> /* Process loops from innermost to outer, stopping at the innermost
> loop we unrolled. */
>
> @@ -1512,10 +1469,14 @@ tree_unroll_loops_completely (bool may_increase_size,
> bool unroll_outer)
> EXECUTE_IF_SET_IN_BITMAP (fathers, 0, i, bi)
> {
> loop_p father = get_loop (cfun, i);
> - basic_block *body = get_loop_body_in_dom_order (father);
> - for (unsigned j = 0; j < father->num_nodes; j++)
> - propagate_constants_for_unrolling (body[j]);
> - free (body);
> + bitmap exit_bbs = BITMAP_ALLOC (NULL);
> + loop_exit *exit = father->exits->next;
> + while (exit->e)
> + {
> + bitmap_set_bit (exit_bbs, exit->e->dest->index);
> + exit = exit->next;
> + }
> + do_rpo_vn (cfun, loop_preheader_edge (father), exit_bbs);
> }
> BITMAP_FREE (fathers);
