On Wed, Mar 29, 2023 at 01:22:27PM -0400, Andrew MacLeod wrote:
> however, as seems to be the case often, better ranges result in, I now get:
>
> FAIL: 23_containers/vector/bool/allocator/copy.cc (test for excess errors)
Our middle-end warnings are just badly designed :(, the better value ranges
are, the more false positives they have.
> commit 358d0ca44faf2e20fbacd0f74386308b5ca52cd4
> Author: Andrew MacLeod <amacl...@redhat.com>
> Date: Tue Mar 28 12:16:34 2023 -0400
>
> Add recursive GORI recompuations with a depth limit.
LGTM for trunk, let's do with the regression incrementally.
Or as Richard mentioned on IRC, one possibility would be to force this
param temporarily to 1 (or whatever matches previous behavior) for the
diagnostic range queries).
You need a ChangeLog entry though...
> diff --git a/gcc/gimple-range-gori.cc b/gcc/gimple-range-gori.cc
> index 6e8dfa85ca8..5f4313b27dd 100644
> --- a/gcc/gimple-range-gori.cc
> +++ b/gcc/gimple-range-gori.cc
> @@ -1308,7 +1308,7 @@ gori_compute::compute_operand1_and_operand2_range
> (vrange &r,
> // direct dependent is exported, it may also change the computed value of
> NAME.
>
> bool
> -gori_compute::may_recompute_p (tree name, basic_block bb)
> +gori_compute::may_recompute_p (tree name, basic_block bb, int depth)
> {
> tree dep1 = depend1 (name);
> tree dep2 = depend2 (name);
> @@ -1322,22 +1322,36 @@ gori_compute::may_recompute_p (tree name, basic_block
> bb)
> if (is_a<gphi *> (s) || gimple_has_side_effects (s))
> return false;
>
> - // If edge is specified, check if NAME can be recalculated on that edge.
> - if (bb)
> - return ((is_export_p (dep1, bb))
> - || (dep2 && is_export_p (dep2, bb)));
> + if (!dep2)
> + {
> + // -1 indicates a default param, convert it to the real default.
> + if (depth == -1)
> + {
> + depth = (int)param_ranger_recompute_depth;
> + gcc_checking_assert (depth >= 1);
> + }
>
> - return (is_export_p (dep1)) || (dep2 && is_export_p (dep2));
> + bool res = (bb ? is_export_p (dep1, bb) : is_export_p (dep1));
> + if (res || depth <= 1)
> + return res;
> + // Check another level of recomputation.
> + return may_recompute_p (dep1, bb, --depth);
> + }
> + // Two dependencies terminate the depth of the search.
> + if (bb)
> + return is_export_p (dep1, bb) || is_export_p (dep2, bb);
> + else
> + return is_export_p (dep1) || is_export_p (dep2);
> }
>
> // Return TRUE if NAME can be recomputed on edge E. If any direct dependent
> // is exported on edge E, it may change the computed value of NAME.
>
> bool
> -gori_compute::may_recompute_p (tree name, edge e)
> +gori_compute::may_recompute_p (tree name, edge e, int depth)
> {
> gcc_checking_assert (e);
> - return may_recompute_p (name, e->src);
> + return may_recompute_p (name, e->src, depth);
> }
>
>
> diff --git a/gcc/gimple-range-gori.h b/gcc/gimple-range-gori.h
> index 0fc90ec8a18..3ea4b45595b 100644
> --- a/gcc/gimple-range-gori.h
> +++ b/gcc/gimple-range-gori.h
> @@ -172,8 +172,8 @@ private:
> bool refine_using_relation (tree op1, vrange &op1_range,
> tree op2, vrange &op2_range,
> fur_source &src, relation_kind k);
> - bool may_recompute_p (tree name, edge e);
> - bool may_recompute_p (tree name, basic_block bb = NULL);
> + bool may_recompute_p (tree name, edge e, int depth = -1);
> + bool may_recompute_p (tree name, basic_block bb = NULL, int depth = -1);
> bool compute_operand_range_switch (vrange &r, gswitch *s, const vrange
> &lhs,
> tree name, fur_source &src);
> bool compute_operand1_range (vrange &r, gimple_range_op_handler &handler,
> diff --git a/gcc/params.opt b/gcc/params.opt
> index 2329d150ef0..b2ec436546c 100644
> --- a/gcc/params.opt
> +++ b/gcc/params.opt
> @@ -900,6 +900,11 @@ Common Joined UInteger Var(param_ranger_logical_depth)
> Init(6) IntegerRange(1, 9
> Maximum depth of logical expression evaluation ranger will look through when
> evaluating outgoing edge ranges.
>
> +-param=ranger-recompute-depth=
> +Common Joined UInteger Var(param_ranger_recompute_depth) Init(5)
> IntegerRange(1, 100) Param Optimization
> +Maximum depth of instruction chains to consider for recomputation in the
> +outgoing range calculator.
> +
> -param=relation-block-limit=
> Common Joined UInteger Var(param_relation_block_limit) Init(200)
> IntegerRange(0, 9999) Param Optimization
> Maximum number of relations the oracle will register in a basic block.
Jakub
