| Message ID | CAELXzTNzN5nWz_ng548x13DEfXDCouD5gb7CW16c=G51CuruMg@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3,POPCOUNT] Handle COND_EXPR in expression_expensive_p | expand |
On Fri, Jun 22, 2018 at 11:14 AM Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org> wrote: > > gcc/ChangeLog: The canonical way is calling simplify_using_initial_conditions on the may_be_zero condition. Richard. > 2018-06-22 Kugan Vivekanandarajah <kuganv@linaro.org> > > * tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount > argument is checked for zero before entering loop, avoid checking again.
Hi Richard, Thanks for the review. On 25 June 2018 at 20:02, Richard Biener <richard.guenther@gmail.com> wrote: > On Fri, Jun 22, 2018 at 11:14 AM Kugan Vivekanandarajah > <kugan.vivekanandarajah@linaro.org> wrote: >> >> gcc/ChangeLog: > > The canonical way is calling simplify_using_initial_conditions on the > may_be_zero condition. > > Richard. > >> 2018-06-22 Kugan Vivekanandarajah <kuganv@linaro.org> >> >> * tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount >> argument is checked for zero before entering loop, avoid checking again. Do you like the attached patch which does this. Thanks, Kugan From 78cb0ea3d058f1d1db73f259825b8bb07eb1ca30 Mon Sep 17 00:00:00 2001 From: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org> Date: Fri, 22 Jun 2018 14:11:28 +1000 Subject: [PATCH 2/3] in niter dont check for zero when it is alrealy checked Change-Id: Ie94a35a1a3c2d8bdffd3dc54a94684c032efc7e0 --- gcc/tree-ssa-loop-niter.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index f5ffc0f..be0cff5 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -2596,10 +2596,15 @@ number_of_iterations_popcount (loop_p loop, edge exit, niter->niter = iter; niter->assumptions = boolean_true_node; + if (adjust) - niter->may_be_zero = fold_build2 (EQ_EXPR, boolean_type_node, src, + { + tree may_be_zero = fold_build2 (EQ_EXPR, boolean_type_node, src, build_zero_cst (TREE_TYPE (src))); + niter->may_be_zero = + simplify_using_initial_conditions (loop, may_be_zero); + } else niter->may_be_zero = boolean_false_node;
On Wed, Jun 27, 2018 at 7:01 AM Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org> wrote: > > Hi Richard, > > Thanks for the review. > > On 25 June 2018 at 20:02, Richard Biener <richard.guenther@gmail.com> wrote: > > On Fri, Jun 22, 2018 at 11:14 AM Kugan Vivekanandarajah > > <kugan.vivekanandarajah@linaro.org> wrote: > >> > >> gcc/ChangeLog: > > > > The canonical way is calling simplify_using_initial_conditions on the > > may_be_zero condition. > > > > Richard. > > > >> 2018-06-22 Kugan Vivekanandarajah <kuganv@linaro.org> > >> > >> * tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount > >> argument is checked for zero before entering loop, avoid checking again. > Do you like the attached patch which does this. Yes. OK if bootstrapped/tested. Richard. > Thanks, > Kugan
From 4f2a6ad5a49eec0a1cae15e033329f889f9137b9 Mon Sep 17 00:00:00 2001 From: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org> Date: Fri, 22 Jun 2018 14:11:28 +1000 Subject: [PATCH 2/3] in niter dont check for zero when it is alrealy checked Change-Id: I98982537bca14cb99a85d0da70d33a6c044385fd --- gcc/tree-ssa-loop-niter.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index 9365915..2299aca 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -2503,6 +2503,7 @@ number_of_iterations_popcount (loop_p loop, edge exit, HOST_WIDE_INT max; adjust = true; tree fn = NULL_TREE; + bool check_zero = true; /* Check loop terminating branch is like if (b != 0). */ @@ -2590,7 +2591,37 @@ number_of_iterations_popcount (loop_p loop, edge exit, niter->niter = iter; niter->assumptions = boolean_true_node; - if (adjust) + if (adjust + && EDGE_COUNT (loop->header->preds) == 2) + { + /* Sometimes, src of the popcount is checked for + zero before entering the loop. In this case we + dont need to check for zero again. */ + edge pred_edge = EDGE_PRED (loop->header, 0); + gimple *stmt = last_stmt (pred_edge->src); + + /* If there is an empty pre-header, go one block + above. */ + if (!stmt + && EDGE_COUNT (pred_edge->src->preds) == 1) + { + pred_edge = EDGE_PRED (pred_edge->src, 0); + stmt = last_stmt (pred_edge->src); + } + + /* If we have the src != 0 check and if we are entering + the loop when the condition is true, we can skip zero + check. */ + if (stmt + && gimple_code (stmt) == GIMPLE_COND + && gimple_cond_code (stmt) == NE_EXPR + && pred_edge->flags & EDGE_TRUE_VALUE + && TREE_CODE (gimple_cond_lhs (stmt)) == SSA_NAME + && (gimple_phi_arg_def (phi, loop_preheader_edge (loop)->dest_idx) + == gimple_cond_lhs (stmt))) + check_zero = false; + } + if (adjust && check_zero) niter->may_be_zero = fold_build2 (EQ_EXPR, boolean_type_node, src, build_zero_cst (TREE_TYPE (src))); -- 2.7.4
gcc/ChangeLog: 2018-06-22 Kugan Vivekanandarajah <kuganv@linaro.org> * tree-ssa-loop-niter.c (number_of_iterations_popcount): If popcount argument is checked for zero before entering loop, avoid checking again.