cmd/internal/obj: Use bitfield for LSym attributes

Reduces the size of LSym struct.

On 32bit: before 84  after 76
On 64bit: before 136 after 128

name       old time/op     new time/op     delta
Template       182ms ± 3%      182ms ± 3%    ~           (p=0.607 n=19+20)
Unicode       93.5ms ± 4%     94.2ms ± 3%    ~           (p=0.141 n=20+19)
GoTypes        608ms ± 1%      605ms ± 2%    ~           (p=0.056 n=20+20)

name       old user-ns/op  new user-ns/op  delta
Template        249M ± 7%       249M ± 4%    ~           (p=0.605 n=18+19)
Unicode         149M ±14%       151M ± 5%    ~           (p=0.724 n=20+17)
GoTypes         855M ± 4%       853M ± 3%    ~           (p=0.537 n=19+19)

name       old alloc/op    new alloc/op    delta
Template      40.3MB ± 0%     40.3MB ± 0%  -0.11%        (p=0.000 n=19+20)
Unicode       33.8MB ± 0%     33.8MB ± 0%  -0.08%        (p=0.000 n=20+20)
GoTypes        119MB ± 0%      119MB ± 0%  -0.10%        (p=0.000 n=19+20)

name       old allocs/op   new allocs/op   delta
Template        383k ± 0%       383k ± 0%    ~           (p=0.703 n=20+20)
Unicode         317k ± 0%       317k ± 0%    ~           (p=0.982 n=19+18)
GoTypes        1.14M ± 0%      1.14M ± 0%    ~           (p=0.086 n=20+20)

Change-Id: Id6ba0db3ecc4503a4e9af3ed0d5884d4366e8bf9
Reviewed-on: https://go-review.googlesource.com/31870
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Shahar Kohanim <skohanim@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
shaharko 2016-10-24 23:15:41 +03:00 committed by Shahar Kohanim
parent 2ee82edfc2
commit d391dc260a
16 changed files with 134 additions and 109 deletions

View file

@ -320,34 +320,10 @@ const (
// An LSym is the sort of symbol that is written to an object file.
type LSym struct {
Name string
Type SymKind
Version int16
Dupok bool
Cfunc bool
Nosplit bool
Leaf bool
Seenglobl bool
Onlist bool
// MakeTypelink means that the type should have an entry in the typelink table.
MakeTypelink bool
// ReflectMethod means the function may call reflect.Type.Method or
// reflect.Type.MethodByName. Matching is imprecise (as reflect.Type
// can be used through a custom interface), so ReflectMethod may be
// set in some cases when the reflect package is not called.
//
// Used by the linker to determine what methods can be pruned.
ReflectMethod bool
// Local means make the symbol local even when compiling Go code to reference Go
// symbols in other shared libraries, as in this mode symbols are global by
// default. "local" here means in the sense of the dynamic linker, i.e. not
// visible outside of the module (shared library or executable) that contains its
// definition. (When not compiling to support Go shared libraries, all symbols are
// local in this sense unless there is a cgo_export_* directive).
Local bool
Name string
Type SymKind
Version int16
Attribute
RefIdx int // Index of this symbol in the symbol reference list.
Args int32
@ -361,6 +337,55 @@ type LSym struct {
R []Reloc
}
// Attribute is a set of symbol attributes.
type Attribute int16
const (
AttrDuplicateOK Attribute = 1 << iota
AttrCFunc
AttrNoSplit
AttrLeaf
AttrSeenGlobl
AttrOnList
// MakeTypelink means that the type should have an entry in the typelink table.
AttrMakeTypelink
// ReflectMethod means the function may call reflect.Type.Method or
// reflect.Type.MethodByName. Matching is imprecise (as reflect.Type
// can be used through a custom interface), so ReflectMethod may be
// set in some cases when the reflect package is not called.
//
// Used by the linker to determine what methods can be pruned.
AttrReflectMethod
// Local means make the symbol local even when compiling Go code to reference Go
// symbols in other shared libraries, as in this mode symbols are global by
// default. "local" here means in the sense of the dynamic linker, i.e. not
// visible outside of the module (shared library or executable) that contains its
// definition. (When not compiling to support Go shared libraries, all symbols are
// local in this sense unless there is a cgo_export_* directive).
AttrLocal
)
func (a Attribute) DuplicateOK() bool { return a&AttrDuplicateOK != 0 }
func (a Attribute) MakeTypelink() bool { return a&AttrMakeTypelink != 0 }
func (a Attribute) CFunc() bool { return a&AttrCFunc != 0 }
func (a Attribute) NoSplit() bool { return a&AttrNoSplit != 0 }
func (a Attribute) Leaf() bool { return a&AttrLeaf != 0 }
func (a Attribute) SeenGlobl() bool { return a&AttrSeenGlobl != 0 }
func (a Attribute) OnList() bool { return a&AttrOnList != 0 }
func (a Attribute) ReflectMethod() bool { return a&AttrReflectMethod != 0 }
func (a Attribute) Local() bool { return a&AttrLocal != 0 }
func (a *Attribute) Set(flag Attribute, value bool) {
if value {
*a |= flag
} else {
*a &^= flag
}
}
// The compiler needs LSym to satisfy fmt.Stringer, because it stores
// an LSym in ssa.ExternSymbol.
func (s *LSym) String() string {