> This one is split from original patch.
This patch is also OK (modulo the changelog entry and testing). Please
wait with comitting this for bit over a day after commiting the first so
the periodic benchmarks picks each change differently.
Thanks,
Honza
>
> Feng
> ---
> diff --git a/gcc/ipa-fnsummary.c b/gcc/ipa-fnsummary.c
> index 1bf1806eaf8..5423756d275 100644
> --- a/gcc/ipa-fnsummary.c
> +++ b/gcc/ipa-fnsummary.c
> @@ -1197,8 +1197,14 @@ set_cond_stmt_execution_predicate (struct
> ipa_func_body_info *fbi,
> ? code : inverted_code);
> /* invert_tree_comparison will return ERROR_MARK on FP
> comparsions that are not EQ/NE instead of returning proper
> - unordered one. Be sure it is not confused with NON_CONSTANT. */
> - if (this_code != ERROR_MARK)
> + unordered one. Be sure it is not confused with NON_CONSTANT.
> +
> + And if the edge's target is the final block of diamond CFG graph
> + of this conditional statement, we do not need to compute
> + predicate for the edge because the final block's predicate must
> + be at least as that of the first block of the statement. */
> + if (this_code != ERROR_MARK
> + && !dominated_by_p (CDI_POST_DOMINATORS, bb, e->dest))
> {
> predicate p
> = add_condition (summary, index, size, &aggpos, this_code,
> @@ -1282,6 +1288,14 @@ set_switch_stmt_execution_predicate (struct
> ipa_func_body_info *fbi,
> *(predicate *) e->aux = false;
> }
>
> + e = gimple_switch_edge (cfun, last, 0);
> + /* Set BOUND_COUNT to maximum count to bypass computing predicate for
> + default case if its target basic block is in convergence point of all
> + switch cases, which can be determined by checking whether it
> + post-dominates the switch statement. */
> + if (dominated_by_p (CDI_POST_DOMINATORS, bb, e->dest))
> + bound_count = INT_MAX;
> +
> n = gimple_switch_num_labels (last);
> for (case_idx = 1; case_idx < n; ++case_idx)
> {
> @@ -1293,7 +1307,12 @@ set_switch_stmt_execution_predicate (struct
> ipa_func_body_info *fbi,
> min = CASE_LOW (cl);
> max = CASE_HIGH (cl);
>
> - if (!max)
> + /* The case's target basic block is in convergence point of all switch
> + cases, its predicate should be at least as that of the switch
> + statement. */
> + if (dominated_by_p (CDI_POST_DOMINATORS, bb, e->dest))
> + p = true;
> + else if (!max)
> p = add_condition (summary, index, size, &aggpos, EQ_EXPR,
> unshare_expr_without_location (min));
> else
> @@ -1463,10 +1482,10 @@ compute_bb_predicates (struct ipa_func_body_info *fbi,
> break;
> }
> }
> - if (p == false)
> - gcc_checking_assert (!bb->aux);
> - else
> + if (p != false)
> {
> + basic_block pdom_bb;
> +
> if (!bb->aux)
> {
> done = false;
> @@ -1485,6 +1504,34 @@ compute_bb_predicates (struct ipa_func_body_info *fbi,
> *((predicate *) bb->aux) = p;
> }
> }
> +
> + /* For switch/if statement, we can OR-combine predicates of all
> + its cases/branches to get predicate for basic block in their
> + convergence point, but sometimes this will generate very
> + complicated predicate. Actually, we can get simplified
> + predicate in another way by using the fact that predicate
> + for a basic block must also hold true for its post dominators.
> + To be specific, basic block in convergence point of
> + conditional statement should include predicate of the
> + statement. */
> + pdom_bb = get_immediate_dominator (CDI_POST_DOMINATORS, bb);
> + if (pdom_bb == EXIT_BLOCK_PTR_FOR_FN (my_function) || !pdom_bb)
> + ;
> + else if (!pdom_bb->aux)
> + {
> + done = false;
> + pdom_bb->aux = edge_predicate_pool.allocate ();
> + *((predicate *) pdom_bb->aux) = p;
> + }
> + else if (p != *(predicate *) pdom_bb->aux)
> + {
> + p = p.or_with (summary->conds, *(predicate *)pdom_bb->aux);
> + if (p != *(predicate *) pdom_bb->aux)
> + {
> + done = false;
> + *((predicate *) pdom_bb->aux) = p;
> + }
> + }
> }
> }
> }
> @@ -2089,6 +2136,7 @@ analyze_function_body (struct cgraph_node *node, bool
> early)
> if (opt_for_fn (node->decl, optimize))
> {
> calculate_dominance_info (CDI_DOMINATORS);
> + calculate_dominance_info (CDI_POST_DOMINATORS);
> if (!early)
> loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
> else
> @@ -2469,6 +2517,7 @@ analyze_function_body (struct cgraph_node *node, bool
> early)
> else if (!ipa_edge_args_sum)
> ipa_free_all_node_params ();
> free_dominance_info (CDI_DOMINATORS);
> + free_dominance_info (CDI_POST_DOMINATORS);
> }
> if (dump_file)
> {
> diff --git a/gcc/testsuite/gcc.dg/ipa/pr91089.c
> b/gcc/testsuite/gcc.dg/ipa/pr91089.c
> index e9e206fc24d..92b5550aa76 100644
> --- a/gcc/testsuite/gcc.dg/ipa/pr91089.c
> +++ b/gcc/testsuite/gcc.dg/ipa/pr91089.c
> @@ -41,6 +41,52 @@ int callee (int i)
> return data += i;
> }
>
> +int fn2 ();
> +
> +int callee_complex_predicate (int i)
> +{
> + switch (i )
> + {
> + case 0:
> + fn ();
> + fn ();
> + fn ();
> + case 1:
> + fn ();
> + fn ();
> + case -1:
> + fn ();
> + case -2:
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + fn ();
> + data += i;
> + break;
> + }
> +
> + if (i == 1000)
> + {
> + int j;
> +
> + for (j = 0; j < 100; j++)
> + fn2 ();
> + }
> + return i + 3;
> +}
> +
> int caller ()
> {
> return callee (-127) +
> @@ -60,3 +106,4 @@ int caller ()
> /* { dg-final { scan-ipa-dump "op0 != 0" "fnsummary" } } */
> /* { dg-final { scan-ipa-dump "op0 < 5" "fnsummary" } } */
> /* { dg-final { scan-ipa-dump "op0 > 7" "fnsummary" } } */
> +/* { dg-final { scan-ipa-dump "loop depth: 1 .+ time:\[ \]*\[0-9\]+
> predicate: \\(op0 == 1000\\)" "fnsummary" } } */
> --
> 2.17.1
