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[dev.regabi] cmd/compile: remove walkReturn "common case" path

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After the previous two optimization CLs, this code path now generates
the same code as ascompatee does anyway. So just use that and remove
some redundant code.

Passes toolstash -cmp.

Change-Id: I5e2e5c6dbea64d8e91abe0f2cf51aa5bb86576d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/281154
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
This commit is contained in:
Matthew Dempsky 2021-01-03 00:03:28 -08:00
parent d36a6bf44d
commit f2e6dab048
1 changed files with 8 additions and 16 deletions
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24
src/cmd/compile/internal/walk/assign.go
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@ -143,7 +143,7 @@ func walkAssignFunc(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
// walkAssignList walks an OAS2 node.
func walkAssignList(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
init.Append(ir.TakeInit(n)...)
return ir.NewBlockStmt(src.NoXPos, ascompatee(ir.OAS, n.Lhs, n.Rhs, init))
return ir.NewBlockStmt(src.NoXPos, ascompatee(ir.OAS, n.Lhs, n.Rhs))
}
// walkAssignMapRead walks an OAS2MAPR node.
@ -244,20 +244,7 @@ func walkReturn(n *ir.ReturnStmt) ir.Node {
dsts[i] = typecheck.AssignExpr(v.Nname.(*ir.Name))
}
if (ir.HasNamedResults(fn) && len(n.Results) > 1) || paramoutheap(fn) {
// General case: For anything tricky, let ascompatee handle
// ordering the assignments correctly.
n.Results = ascompatee(n.Op(), dsts, n.Results, n.PtrInit())
return n
}
// Common case: Assignment order doesn't matter. Simply assign to
// each result parameter in order.
var res ir.Nodes
for i, v := range n.Results {
appendWalkStmt(&res, convas(ir.NewAssignStmt(base.Pos, dsts[i], v), &res))
}
n.Results = res
n.Results = ascompatee(n.Op(), dsts, n.Results)
return n
}
@ -318,7 +305,7 @@ func ascompatet(nl ir.Nodes, nr *types.Type) []ir.Node {
// check assign expression list to
// an expression list. called in
// expr-list = expr-list
func ascompatee(op ir.Op, nl, nr []ir.Node, init *ir.Nodes) []ir.Node {
func ascompatee(op ir.Op, nl, nr []ir.Node) []ir.Node {
// cannot happen: should have been rejected during type checking
if len(nl) != len(nr) {
base.Fatalf("assignment operands mismatch: %+v / %+v", ir.Nodes(nl), ir.Nodes(nr))
@ -413,6 +400,11 @@ func ascompatee(op ir.Op, nl, nr []ir.Node, init *ir.Nodes) []ir.Node {
// We can ignore assignments to blank.
continue
}
if op == ir.ORETURN && types.OrigSym(name.Sym()) == nil {
// We can also ignore assignments to anonymous result
// parameters. These can't appear in expressions anyway.
continue
}
assigned.Add(name)
}