From: Xiong Hu Luo <luo...@linux.ibm.com>
For SPEC2017 exchange2, there is a large recursive functiondigits_2(function
size 1300) generates specialized node from digits_2.1 to digits_2.8 with added
build option:
--param ipa-cp-eval-threshold=1 --param ipa-cp-unit-growth=80
ipa-inline pass will consider inline these nodes called only once, but these
large functions inlined too deeply will cause serious register spill and
performance down as followed.
inlineA: brute (inline digits_2.1, 2.2, 2.3, 2.4) -> digits_2.5 (inline 2.6,
2.7, 2.8)
inlineB: digits_2.1 (inline digits_2.2, 2.3) -> call digits_2.4 (inline
digits_2.5, 2.6) -> call digits_2.7 (inline 2.8)
inlineC: brute (inline digits_2) -> call 2.1 -> 2.2 (inline 2.3) -> 2.4 -> 2.5
-> 2.6 (inline 2.7 ) -> 2.8
inlineD: brute -> call digits_2 -> call 2.1 -> call 2.2 -> 2.3 -> 2.4 -> 2.5 ->
2.6 -> 2.7 -> 2.8
Performance diff:
inlineB is ~25% faster than inlineA;
inlineC is ~20% faster than inlineB;
inlineD is ~30% faster than inlineC.
The master GCC code now generates inline sequence like inlineB, this patch
makes the ipa-inline pass behavior like inlineD by:
1) The growth acumulation for recursive calls by adding the growth data
to the edge when edge's caller is inlined into another function to avoid
inline too deeply;
2) And if caller and callee are both specialized from same node, the edge
should also be considered as recursive edge.
SPEC2017 test shows GEOMEAN improve +2.75% in total(+0.56% without exchange2).
Any comments? Thanks.
523.xalancbmk_r +1.32%
541.leela_r +1.51%
548.exchange2_r +31.87%
507.cactuBSSN_r +0.80%
526.blender_r +1.25%
538.imagick_r +1.82%
gcc/ChangeLog:
2020-08-12 Xionghu Luo <luo...@linux.ibm.com>
* cgraph.h (cgraph_edge::recursive_p): Return true if caller and
callee and specialized from same node.
* ipa-inline-analysis.c (do_estimate_growth_1): Add caller's
inlined_to growth to edge whose caller is inlined.
---
gcc/cgraph.h | 2 ++
gcc/ipa-inline-analysis.c | 3 +++
2 files changed, 5 insertions(+)
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index 0211f08964f..11903ac1960 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -3314,6 +3314,8 @@ cgraph_edge::recursive_p (void)
cgraph_node *c = callee->ultimate_alias_target ();
if (caller->inlined_to)
return caller->inlined_to->decl == c->decl;
+ else if (caller->clone_of && c->clone_of)
+ return caller->clone_of->decl == c->clone_of->decl;
else
return caller->decl == c->decl;
}
diff --git a/gcc/ipa-inline-analysis.c b/gcc/ipa-inline-analysis.c
index 148efbc09ef..ba0cf836364 100644
--- a/gcc/ipa-inline-analysis.c
+++ b/gcc/ipa-inline-analysis.c
@@ -434,6 +434,9 @@ do_estimate_growth_1 (struct cgraph_node *node, void *data)
continue;
}
d->growth += estimate_edge_growth (e);
+ if (e->caller->inlined_to)
+ d->growth += ipa_fn_summaries->get (e->caller->inlined_to)->growth;
+
if (d->growth > d->cap)
return true;
}
--
2.25.1
