cmd/compile: fuse escape analysis parameter tagging loops

Simplifies the code somewhat and allows removing Param.Field. Passes toolstash-check. Change-Id: Id854416aea8afd27ce4830ff0f5ff940f7353792 Reviewed-on: https://go-review.googlesource.com/99336 Run-TryBot: Matthew Dempsky <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Cherry Zhang <[email protected]>
cloudflare · Mar 8, 2018 · e3127f0 · e3127f0
1 parent 7d654af
commit e3127f0
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Showing 4 changed files with 12 additions and 35 deletions.
diff --git a/src/cmd/compile/internal/gc/dcl.go b/src/cmd/compile/internal/gc/dcl.go
@@ -668,11 +668,6 @@ func tofunargs(l []*Node, funarg types.Funarg) *types.Type {
  for i, n := range l {
  f := structfield(n)
  f.Funarg = funarg
-
- // esc.go needs to find f given a PPARAM to add the tag.
- if n.Left != nil && n.Left.Class() == PPARAM {
- n.Left.Name.Param.Field = f
- }
  if f.Broke() {
  t.SetBroke(true)
  }
@@ -688,11 +683,6 @@ func tofunargsfield(fields []*types.Field, funarg types.Funarg) *types.Type {
 
  for _, f := range fields {
  f.Funarg = funarg
-
- // esc.go needs to find f given a PPARAM to add the tag.
- if asNode(f.Nname) != nil && asNode(f.Nname).Class() == PPARAM {
- asNode(f.Nname).Name.Param.Field = f
- }
  }
  t.SetFields(fields)
  return t

diff --git a/src/cmd/compile/internal/gc/esc.go b/src/cmd/compile/internal/gc/esc.go
@@ -2238,27 +2238,6 @@ func (e *EscState) esctag(fn *Node) {
  }
  }
 
- for _, ln := range fn.Func.Dcl {
- if ln.Op != ONAME {
- continue
- }
-
- switch ln.Esc & EscMask {
- case EscNone, // not touched by escflood
- EscReturn:
- if types.Haspointers(ln.Type) { // don't bother tagging for scalars
- if ln.Name.Param.Field.Note != uintptrEscapesTag {
- ln.Name.Param.Field.Note = mktag(int(ln.Esc))
- }
- }
-
- case EscHeap: // touched by escflood, moved to heap
- }
- }
-
- // Unnamed parameters are unused and therefore do not escape.
- // (Unnamed parameters are not in the Dcl list in the loop above
- // so we need to mark them separately.)
  for _, fs := range types.RecvsParams {
  for _, f := range fs(fn.Type).Fields().Slice() {
  if !types.Haspointers(f.Type) { // don't bother tagging for scalars
@@ -2268,8 +2247,19 @@ func (e *EscState) esctag(fn *Node) {
  // Note is already set in the loop above.
  continue
  }
+
+ // Unnamed parameters are unused and therefore do not escape.
  if f.Sym == nil || f.Sym.IsBlank() {
  f.Note = mktag(EscNone)
+ continue
+ }
+
+ switch esc := asNode(f.Nname).Esc; esc & EscMask {
+ case EscNone, // not touched by escflood
+ EscReturn:
+ f.Note = mktag(int(esc))
+
+ case EscHeap: // touched by escflood, moved to heap
  }
  }
  }

diff --git a/src/cmd/compile/internal/gc/sizeof_test.go b/src/cmd/compile/internal/gc/sizeof_test.go
@@ -24,7 +24,7 @@ func TestSizeof(t *testing.T) {
  }{
  {Func{}, 128, 232},
  {Name{}, 32, 56},
- {Param{}, 28, 56},
+ {Param{}, 24, 48},
  {Node{}, 76, 128},
  }
 

diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
@@ -279,9 +279,6 @@ type Param struct {
  // ONAME PAUTOHEAP
  Stackcopy *Node // the PPARAM/PPARAMOUT on-stack slot (moved func params only)
 
- // ONAME PPARAM
- Field *types.Field // TFIELD in arg struct
-
  // ONAME closure linkage
  // Consider:
  //