v2 Changes:
1. Enable proportion orig_sum to the new nodes for self recursive node:
new_sum = (orig_sum + new_sum) \
* self_recursive_probability * (1 / param_ipa_cp_max_recursive_depth).
2. Add value range for param_ipa_cp_max_recursive_depth.
The performance of exchange2 built with PGO will decrease ~28% by r278808
due to profile count set incorrectly. The cloned nodes are updated to a
very small count caused later pass cunroll fail to unroll the recursive
function in exchange2.
digits_2 ->
digits_2.constprop.0, digits_2.constprop.1, etc.
gcc/ChangeLog:
2019-12-26 Luo Xiong Hu <luo...@linux.ibm.com>
* ipa-cp.c (update_profiling_info): Check self_scc node.
* params.opt (ipa-cp-max-recursive-depth): Set param range.
---
gcc/ipa-cp.c | 25 +++++++++++++++++++++++++
gcc/params.opt | 2 +-
2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index 14064ae0034..947bf7c7199 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -4272,6 +4272,31 @@ update_profiling_info (struct cgraph_node *orig_node,
false);
new_sum = stats.count_sum;
+ class ipa_node_params *info = IPA_NODE_REF (orig_node);
+ if (info && info->node_is_self_scc)
+ {
+ profile_count self_recursive_count;
+
+ /* The self recursive edge is on the orig_node. */
+ for (cs = orig_node->callees; cs; cs = cs->next_callee)
+ if (ipa_edge_within_scc (cs))
+ {
+ cgraph_node *callee = cs->callee->function_symbol ();
+ if (callee && cs->caller == cs->callee)
+ {
+ self_recursive_count = cs->count;
+ break;
+ }
+ }
+
+ /* Proportion count for self recursive node from all callers. */
+ new_sum
+ = (orig_sum + new_sum).apply_scale (self_recursive_count, orig_sum);
+
+ /* Proportion count for specialized cloned node. */
+ new_sum = new_sum.apply_scale (1, param_ipa_cp_max_recursive_depth);
+ }
+
if (orig_node_count < orig_sum + new_sum)
{
if (dump_file)
diff --git a/gcc/params.opt b/gcc/params.opt
index d88ae0c468b..40a03b04580 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -199,7 +199,7 @@ Common Joined UInteger Var(param_ipa_cp_loop_hint_bonus)
Init(64) Param
Compile-time bonus IPA-CP assigns to candidates which make loop bounds or
strides known.
-param=ipa-cp-max-recursive-depth=
-Common Joined UInteger Var(param_ipa_cp_max_recursive_depth) Init(8) Param
+Common Joined UInteger Var(param_ipa_cp_max_recursive_depth) Init(8)
IntegerRange(1, 10) Param
Maximum depth of recursive cloning for self-recursive function.
-param=ipa-cp-min-recursive-probability=
--
2.21.0.777.g83232e3864
