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author | Matthew Dempsky <mdempsky@google.com> | 2021-06-23 00:49:03 -0700 |
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committer | Matthew Dempsky <mdempsky@google.com> | 2021-06-23 16:48:35 +0000 |
commit | a72a499c24cfcfce2a16ac7c228c2c914c4f36c4 (patch) | |
tree | 19042a1078728d438c7c3970ea63e5b209577b99 /src/cmd/compile/internal/escape | |
parent | eb691fdd62c9f1dc36c9c9a974ac2ddad677fd99 (diff) | |
download | go-a72a499c24cfcfce2a16ac7c228c2c914c4f36c4.tar.gz go-a72a499c24cfcfce2a16ac7c228c2c914c4f36c4.zip |
[dev.typeparams] cmd/compile: optimize wrapping of constant arguments
When wrapping a go/defer statement like:
go f(g(), "x", 42)
we were wrapping it like:
_0, _1, _2, _3 := f, g(), "x", 42
go func() { _0(_1, _2, _3) }()
This is simple and general (and often necessary), but suboptimal in
some cases, such as this. Instead of evaluating the constant arguments
at the go/defer statement, and storing them into the closure context,
we can just keep them in the wrapped call expression.
This CL changes the code to instead generate (assuming f is a declared
function, not a function-typed variable):
_0 := g()
go func() { f(_0, "x", 42) }()
Change-Id: I2bdd4951e7ee93363e1656ecf9b5bd69a121c38a
Reviewed-on: https://go-review.googlesource.com/c/go/+/330332
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Diffstat (limited to 'src/cmd/compile/internal/escape')
-rw-r--r-- | src/cmd/compile/internal/escape/call.go | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/escape/call.go b/src/cmd/compile/internal/escape/call.go index 850b9cbde2..b8e28cd46a 100644 --- a/src/cmd/compile/internal/escape/call.go +++ b/src/cmd/compile/internal/escape/call.go @@ -293,6 +293,18 @@ func (e *escape) rewriteArgument(argp *ir.Node, init *ir.Nodes, call ir.Node, fn } visit := func(pos src.XPos, argp *ir.Node) { + // Optimize a few common constant expressions. By leaving these + // untouched in the call expression, we let the wrapper handle + // evaluating them, rather than taking up closure context space. + switch arg := *argp; arg.Op() { + case ir.OLITERAL, ir.ONIL, ir.OMETHEXPR: + return + case ir.ONAME: + if arg.(*ir.Name).Class == ir.PFUNC { + return + } + } + if unsafeUintptr(*argp) { return } |