Currently liveness information is kept in a map keyed by *ssa.Value.
This made sense when liveness information was sparse, but now we have
liveness for nearly every ssa.Value. There's a fair amount of memory
and CPU overhead to this map now.
This CL replaces this map with a slice indexed by value ID.
Passes toolstash -cmp.
name old time/op new time/op delta
Template 197ms ± 1% 194ms ± 1% -1.60% (p=0.000 n=9+10)
Unicode 100ms ± 2% 99ms ± 1% -1.31% (p=0.012 n=8+10)
GoTypes 695ms ± 1% 689ms ± 0% -0.94% (p=0.000 n=10+10)
Compiler 3.34s ± 2% 3.29s ± 1% -1.26% (p=0.000 n=10+9)
SSA 8.08s ± 0% 8.02s ± 2% -0.70% (p=0.034 n=8+10)
Flate 133ms ± 1% 131ms ± 1% -1.04% (p=0.006 n=10+9)
GoParser 163ms ± 1% 162ms ± 1% -0.79% (p=0.034 n=8+10)
Reflect 459ms ± 1% 454ms ± 0% -1.06% (p=0.000 n=10+8)
Tar 186ms ± 1% 185ms ± 1% -0.87% (p=0.003 n=9+9)
XML 238ms ± 1% 235ms ± 1% -1.01% (p=0.004 n=8+9)
[Geo mean] 418ms 414ms -1.06%
name old alloc/op new alloc/op delta
Template 36.4MB ± 0% 35.6MB ± 0% -2.29% (p=0.000 n=9+10)
Unicode 29.7MB ± 0% 29.5MB ± 0% -0.68% (p=0.000 n=10+10)
GoTypes 119MB ± 0% 117MB ± 0% -2.30% (p=0.000 n=9+9)
Compiler 546MB ± 0% 532MB ± 0% -2.47% (p=0.000 n=10+10)
SSA 1.59GB ± 0% 1.55GB ± 0% -2.41% (p=0.000 n=10+10)
Flate 24.9MB ± 0% 24.5MB ± 0% -1.77% (p=0.000 n=8+10)
GoParser 29.5MB ± 0% 28.7MB ± 0% -2.60% (p=0.000 n=9+10)
Reflect 81.7MB ± 0% 80.5MB ± 0% -1.49% (p=0.000 n=10+10)
Tar 35.7MB ± 0% 35.1MB ± 0% -1.64% (p=0.000 n=10+10)
XML 45.0MB ± 0% 43.7MB ± 0% -2.76% (p=0.000 n=9+10)
[Geo mean] 80.1MB 78.4MB -2.04%
name old allocs/op new allocs/op delta
Template 336k ± 0% 335k ± 0% -0.31% (p=0.000 n=9+10)
Unicode 339k ± 0% 339k ± 0% -0.05% (p=0.000 n=10+10)
GoTypes 1.18M ± 0% 1.18M ± 0% -0.26% (p=0.000 n=10+10)
Compiler 4.96M ± 0% 4.94M ± 0% -0.24% (p=0.000 n=10+10)
SSA 12.6M ± 0% 12.5M ± 0% -0.30% (p=0.000 n=10+10)
Flate 224k ± 0% 223k ± 0% -0.30% (p=0.000 n=10+10)
GoParser 282k ± 0% 281k ± 0% -0.32% (p=0.000 n=10+10)
Reflect 965k ± 0% 963k ± 0% -0.27% (p=0.000 n=9+10)
Tar 331k ± 0% 330k ± 0% -0.27% (p=0.000 n=10+10)
XML 393k ± 0% 392k ± 0% -0.26% (p=0.000 n=10+10)
[Geo mean] 763k 761k -0.26%
Updates #24543.
Change-Id: I4cfd2461510d3c026a262760bca225dc37482341
Reviewed-on: https://go-review.googlesource.com/110178
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
// livenessMap maps from safe points (i.e., CALLs) to their
// liveness map indexes.
- //
- // TODO(austin): Now that we have liveness at almost every PC,
- // should this be a dense structure?
livenessMap LivenessMap
stackMapSet bvecSet
stackMaps []bvec
// LivenessMap maps from *ssa.Value to LivenessIndex.
type LivenessMap struct {
- m map[*ssa.Value]LivenessIndex
+ m []LivenessIndex
+}
+
+func (m *LivenessMap) reset(ids int) {
+ m2 := m.m
+ if ids > cap(m2) {
+ m2 = make([]LivenessIndex, ids)
+ } else {
+ m2 = m2[:ids]
+ }
+ none := LivenessInvalid
+ for i := range m2 {
+ m2[i] = none
+ }
+ m.m = m2
+}
+
+func (m *LivenessMap) set(v *ssa.Value, i LivenessIndex) {
+ m.m[v.ID] = i
}
func (m LivenessMap) Get(v *ssa.Value) LivenessIndex {
- if i, ok := m.m[v]; ok {
- return i
+ if int(v.ID) < len(m.m) {
+ return m.m[int(v.ID)]
}
// Not a safe point.
return LivenessInvalid
stkptrsize: stkptrsize,
be: make([]BlockEffects, f.NumBlocks()),
- livenessMap: LivenessMap{make(map[*ssa.Value]LivenessIndex)},
- regMapSet: make(map[liveRegMask]int),
+ regMapSet: make(map[liveRegMask]int),
}
nblocks := int32(len(f.Blocks))
be.avarinitany = bulk.next()
be.avarinitall = bulk.next()
}
+ lv.livenessMap.reset(lv.f.NumValues())
lv.markUnsafePoints()
return lv
}
for _, v := range b.Values {
if lv.issafepoint(v) {
- lv.livenessMap.m[v] = add(lv.livevars[pos])
+ lv.livenessMap.set(v, add(lv.livevars[pos]))
pos++
}
}
lv.clobber()
if debuglive > 0 {
lv.showlive(nil, lv.stackMaps[0])
- for val, idx := range lv.livenessMap.m {
- lv.showlive(val, lv.stackMaps[idx.stackMapIndex])
+ for _, b := range f.Blocks {
+ for _, val := range b.Values {
+ if idx := lv.livenessMap.Get(val); idx.Valid() {
+ lv.showlive(val, lv.stackMaps[idx.stackMapIndex])
+ }
+ }
}
}
if debuglive >= 2 {