From 0ce7569ee76fda7e5a68b0fe14c93a3e8eb7d108 Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Sat, 25 Apr 2020 10:06:37 +0200
Subject: pkg/compiler: deduplicate Types in descriptions

Add prog.Ref Type that serves as a proxy for real types
and allows to deduplicate Types in generated descriptions.
The Ref type is effectively an index in an array of types.
Just before serialization pkg/compiler replaces real types
with the Ref types and prepares corresponding array of real types.
When a Target is registered in prog package, we do the opposite
operation and replace Ref's with the corresponding real types.

This brings improvements across the board:
compiler memory consumption is reduced by 15%,
test building time by 25%, descriptions size by 33%.

Before:
$ du -h sys/linux/gen
54M	sys/linux/gen

$ time GOMAXPROCS=1 go test -p=1 -c ./prog
real	0m54.200s
real	0m53.883s

$ time GOMAXPROCS=1 go install -p=1 ./tools/syz-execprog
real	0m27.911s
real	0m27.767s

$ TIME="%e %P %M" GOMAXPROCS=1 time go tool compile ./sys/linux/gen
20.59 100% 3200016
20.97 100% 3445976
20.25 100% 3209684

After:
$ du -h sys/linux/gen
36M	sys/linux/gen

$ time GOMAXPROCS=1 go test -p=1 -c ./prog
real	0m42.290s
real	0m43.230s

$ time GOMAXPROCS=1 go install -p=1 ./tools/syz-execprog
real	0m24.337s
real	0m24.727s

$ TIME="%e %P %M" GOMAXPROCS=1 time go tool compile ./sys/linux/gen
19.11 100% 2764952
19.66 100% 2787624
19.35 100% 2749376

Update #1580
---
 pkg/compiler/compiler.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

(limited to 'pkg/compiler/compiler.go')

diff --git a/pkg/compiler/compiler.go b/pkg/compiler/compiler.go
index a9146305b..7316b4d4c 100644
--- a/pkg/compiler/compiler.go
+++ b/pkg/compiler/compiler.go
@@ -37,6 +37,7 @@ type Prog struct {
 	Resources   []*prog.ResourceDesc
 	Syscalls    []*prog.Syscall
 	StructDescs []*prog.KeyedStruct
+	Types       []prog.Type
 	// Set of unsupported syscalls/flags.
 	Unsupported map[string]bool
 	// Returned if consts was nil.
@@ -103,10 +104,13 @@ func Compile(desc *ast.Description, consts map[string]uint64, target *targets.Ta
 		return nil
 	}
 	syscalls := comp.genSyscalls()
+	structs := comp.genStructDescs(syscalls)
+	types := comp.generateTypes(syscalls, structs)
 	prg := &Prog{
 		Resources:   comp.genResources(),
 		Syscalls:    syscalls,
-		StructDescs: comp.genStructDescs(syscalls),
+		StructDescs: structs,
+		Types:       types,
 		Unsupported: comp.unsupported,
 	}
 	if comp.errors != 0 {
-- 
cgit mrf-deployment