Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

cmd/internal/obj: change Prog.From3 to RestArgs ([]Addr)

Browse source 
This change makes it easier to express instructions
with arbitrary number of operands.

Rationale: previous approach with operand "hiding" does
not scale well, AVX and especially AVX512 have many
instructions with 3+ operands.

x86 asm backend is updated to handle up to 6 explicit operands.
It also fixes issue with 4-th immediate operand type checks.
All `ytab` tables are updated accordingly.

Changes to non-x86 backends only include these patterns:
`p.From3 = X` => `p.SetFrom3(X)`
`p.From3.X = Y` => `p.GetFrom3().X = Y`

Over time, other backends can adapt Prog.RestArgs
and reduce the amount of workarounds.

-- Performance --

x/benchmark/build:

$ benchstat upstream.bench patched.bench
name      old time/op                 new time/op                 delta
Build-48                  21.7s ± 2%                  21.8s ± 2%   ~     (p=0.218 n=10+10)

name      old binary-size             new binary-size             delta
Build-48                  10.3M ± 0%                  10.3M ± 0%   ~     (all equal)

name      old build-time/op           new build-time/op           delta
Build-48                  21.7s ± 2%                  21.8s ± 2%   ~     (p=0.218 n=10+10)

name      old build-peak-RSS-bytes    new build-peak-RSS-bytes    delta
Build-48                  145MB ± 5%                  148MB ± 5%   ~     (p=0.218 n=10+10)

name      old build-user+sys-time/op  new build-user+sys-time/op  delta
Build-48                  21.0s ± 2%                  21.2s ± 2%   ~     (p=0.075 n=10+10)

Microbenchmark shows a slight slowdown.

name        old time/op  new time/op  delta
AMD64asm-4  49.5ms ± 1%  49.9ms ± 1%  +0.67%  (p=0.001 n=23+15)

func BenchmarkAMD64asm(b *testing.B) {
  for i := 0; i < b.N; i++ {
    TestAMD64EndToEnd(nil)
    TestAMD64Encoder(nil)
  }
}

Change-Id: I4f1d37b5c2c966da3f2127705ccac9bff0038183
Reviewed-on: https://go-review.googlesource.com/63490
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This commit is contained in:
isharipo 2017-09-13 14:32:08 +03:00 • committed by Matthew Dempsky
parent e1cf2be7a8
commit 8c67f210a1
21 changed files with 513 additions and 481 deletions
Download patch file Download diff file Expand all files Collapse all files

17
src/cmd/internal/obj/util.go
View file

@ -83,11 +83,7 @@ func (p *Prog) String() string {
fmt.Fprintf(&buf, "%.5d (%v)\t%v%s", p.Pc, p.Line(), p.As, sc)
sep := "\t"
quadOpAmd64 := p.RegTo2 == -1
if quadOpAmd64 {
fmt.Fprintf(&buf, "%s$%d", sep, p.From3.Offset)
sep = ", "
}
if p.From.Type != TYPE_NONE {
fmt.Fprintf(&buf, "%s%v", sep, Dconv(p, &p.From))
sep = ", "
@ -97,14 +93,11 @@ func (p *Prog) String() string {
fmt.Fprintf(&buf, "%s%v", sep, Rconv(int(p.Reg)))
sep = ", "
}
if p.From3Type() != TYPE_NONE {
if quadOpAmd64 {
fmt.Fprintf(&buf, "%s%v", sep, Rconv(int(p.From3.Reg)))
} else {
fmt.Fprintf(&buf, "%s%v", sep, Dconv(p, p.From3))
}
for i := range p.RestArgs {
fmt.Fprintf(&buf, "%s%v", sep, Dconv(p, &p.RestArgs[i]))
sep = ", "
}
if p.As == ATEXT {
// If there are attributes, print them. Otherwise, skip the comma.
// In short, print one of these two:
@ -119,7 +112,7 @@ func (p *Prog) String() string {
if p.To.Type != TYPE_NONE {
fmt.Fprintf(&buf, "%s%v", sep, Dconv(p, &p.To))
}
if p.RegTo2 != REG_NONE && !quadOpAmd64 {
if p.RegTo2 != REG_NONE {
fmt.Fprintf(&buf, "%s%v", sep, Rconv(int(p.RegTo2)))
}
return buf.String()