cmd/compile: share dominator tree among many passes

These passes do not modify the dominator tree too much.

% benchstat old.txt new.txt
name       old time/op     new time/op     delta
Template       335ms ± 3%      325ms ± 8%    ~             (p=0.074 n=8+9)
GoTypes        1.05s ± 1%      1.05s ± 3%    ~            (p=0.095 n=9+10)
Compiler       5.37s ± 4%      5.29s ± 1%  -1.42%         (p=0.022 n=9+10)
MakeBash       34.9s ± 3%      34.4s ± 2%    ~            (p=0.095 n=9+10)

name       old alloc/op    new alloc/op    delta
Template      55.4MB ± 0%     54.9MB ± 0%  -0.81%        (p=0.000 n=10+10)
GoTypes        179MB ± 0%      178MB ± 0%  -0.89%        (p=0.000 n=10+10)
Compiler       807MB ± 0%      798MB ± 0%  -1.10%        (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        498k ± 0%       496k ± 0%  -0.29%          (p=0.000 n=9+9)
GoTypes        1.42M ± 0%      1.41M ± 0%  -0.24%        (p=0.000 n=10+10)
Compiler       5.61M ± 0%      5.60M ± 0%  -0.12%        (p=0.000 n=10+10)

Change-Id: I4cd20cfba3f132ebf371e16046ab14d7e42799ec
Reviewed-on: https://go-review.googlesource.com/21806
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This commit is contained in:
Alexandru Moșoi 2016-04-11 21:51:29 +02:00 committed by Alexandru Moșoi
parent a223ccae38
commit 9743e4b031
7 changed files with 36 additions and 17 deletions

View file

@ -234,6 +234,7 @@ var passes = [...]pass{
{name: "zero arg cse", fn: zcse, required: true}, // required to merge OpSB values
{name: "opt deadcode", fn: deadcode, required: true}, // remove any blocks orphaned during opt
{name: "generic cse", fn: cse},
{name: "generic domtree", fn: domTree},
{name: "phiopt", fn: phiopt},
{name: "nilcheckelim", fn: nilcheckelim},
{name: "prove", fn: prove},
@ -288,6 +289,10 @@ var passOrder = [...]constraint{
{"opt", "nilcheckelim"},
// tighten should happen before lowering to avoid splitting naturally paired instructions such as CMP/SET
{"tighten", "lower"},
// nilcheckelim, prove and loopbce share idom.
{"generic domtree", "nilcheckelim"},
{"generic domtree", "prove"},
{"generic domtree", "loopbce"},
// tighten will be most effective when as many values have been removed as possible
{"generic deadcode", "tighten"},
{"generic cse", "tighten"},