Commit b87fcc6e authored by Josh Bleecher Snyder's avatar Josh Bleecher Snyder

cmd/compile: number autotmps per-func, not per-package

Prior to this CL, autotmps were global to a package.
They also shared numbering with static variables.
Switch autotmp numbering to be per-function instead,
and do implicit numbering based on len(Func.Dcl).
This eliminates a dependency on a global variable
from the backend without adding to the Func struct.
While we're here, move statuniqgen closer to its
sole remaining user.

This actually improves compiler performance,
because the autotmp_* names can now be
reused across functions.

name       old alloc/op    new alloc/op    delta
Template      40.6MB ± 0%     40.1MB ± 0%  -1.38%  (p=0.000 n=10+10)
Unicode       29.9MB ± 0%     29.9MB ± 0%    ~     (p=0.912 n=10+10)
GoTypes        116MB ± 0%      114MB ± 0%  -1.53%  (p=0.000 n=10+10)
SSA            865MB ± 0%      856MB ± 0%  -1.04%  (p=0.000 n=10+10)
Flate         25.8MB ± 0%     25.4MB ± 0%  -1.36%  (p=0.000 n=10+10)
GoParser      32.2MB ± 0%     32.0MB ± 0%  -0.72%  (p=0.000 n=10+10)
Reflect       80.3MB ± 0%     79.0MB ± 0%  -1.65%  (p=0.000 n=9+10)
Tar           27.0MB ± 0%     26.7MB ± 0%  -0.86%  (p=0.000 n=10+9)
XML           42.8MB ± 0%     42.4MB ± 0%  -0.95%  (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        398k ± 1%       396k ± 1%  -0.59%  (p=0.002 n=10+10)
Unicode         321k ± 1%       321k ± 0%    ~     (p=0.912 n=10+10)
GoTypes        1.17M ± 0%      1.16M ± 0%  -0.77%  (p=0.000 n=10+10)
SSA            7.65M ± 0%      7.62M ± 0%  -0.40%  (p=0.000 n=10+10)
Flate           240k ± 1%       238k ± 1%  -0.56%  (p=0.001 n=10+10)
GoParser        323k ± 1%       320k ± 1%  -0.65%  (p=0.002 n=10+10)
Reflect        1.01M ± 0%      1.00M ± 0%  -0.37%  (p=0.001 n=9+10)
Tar             256k ± 1%       255k ± 0%    ~     (p=0.101 n=10+8)
XML             400k ± 1%       398k ± 1%    ~     (p=0.063 n=10+10)


Change-Id: I3c23ca98129137d373106990b1a3e1507bbe0cc3
Reviewed-on: https://go-review.googlesource.com/38729
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarMatthew Dempsky <mdempsky@google.com>
parent 8ee2d5bc
......@@ -10,6 +10,7 @@ import (
"cmd/internal/obj"
"cmd/internal/src"
"fmt"
"strconv"
)
func Sysfunc(name string) *obj.LSym {
......@@ -182,6 +183,17 @@ func moveToHeap(n *Node) {
}
}
// autotmpname returns the name for an autotmp variable numbered n.
func autotmpname(n int) string {
// Give each tmp a different name so that they can be registerized.
// Add a preceding . to avoid clashing with legal names.
const prefix = ".autotmp_"
// Start with a buffer big enough to hold a large n.
b := []byte(prefix + " ")[:len(prefix)]
b = strconv.AppendInt(b, int64(n), 10)
return internString(b)
}
// make a new Node off the books
func tempname(nn *Node, t *Type) {
if Curfn == nil {
......@@ -191,16 +203,14 @@ func tempname(nn *Node, t *Type) {
Dump("tempname", Curfn)
Fatalf("adding tempname to wrong closure function")
}
if t == nil {
Fatalf("tempname called with nil type")
}
// give each tmp a different name so that there
// a chance to registerizer them.
// Add a preceding . to avoid clash with legal names.
s := lookupN(".autotmp_", statuniqgen)
statuniqgen++
s := &Sym{
Name: autotmpname(len(Curfn.Func.Dcl)),
Pkg: localpkg,
}
n := newname(s)
s.Def = n
n.Type = t
......
......@@ -242,8 +242,6 @@ var funcsyms []*Sym
var dclcontext Class // PEXTERN/PAUTO
var statuniqgen int // name generator for static temps
var Curfn *Node
var Widthptr int
......
......@@ -569,6 +569,8 @@ const (
// data statements for the constant
// part of the composite literal.
var statuniqgen int // name generator for static temps
// staticname returns a name backed by a static data symbol.
// Callers should call n.Name.SetReadonly(true) on the
// returned node for readonly nodes.
......
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