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cbcf8efa5f
That way we don't need to call into the runtime for every type assertion (to an interface type). name old time/op new time/op delta TypeAssert-24 3.78ns ± 3% 1.00ns ± 1% -73.53% (p=0.000 n=10+8) Change-Id: I0ba308aaf0f24a5495b4e13c814d35af0c58bfde Reviewed-on: https://go-review.googlesource.com/c/go/+/529316 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
61 lines
1.6 KiB
Go
61 lines
1.6 KiB
Go
// Copyright 2023 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package abi
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type InterfaceSwitch struct {
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Cache *InterfaceSwitchCache
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NCases int
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// Array of NCases elements.
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// Each case must be a non-empty interface type.
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Cases [1]*InterfaceType
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}
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type InterfaceSwitchCache struct {
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Mask uintptr // mask for index. Must be a power of 2 minus 1
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Entries [1]InterfaceSwitchCacheEntry // Mask+1 entries total
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}
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type InterfaceSwitchCacheEntry struct {
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// type of source value (a *Type)
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Typ uintptr
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// case # to dispatch to
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Case int
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// itab to use for resulting case variable (a *runtime.itab)
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Itab uintptr
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}
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const go122InterfaceSwitchCache = true
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func UseInterfaceSwitchCache(goarch string) bool {
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if !go122InterfaceSwitchCache {
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return false
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}
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// We need an atomic load instruction to make the cache multithreaded-safe.
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// (AtomicLoadPtr needs to be implemented in cmd/compile/internal/ssa/_gen/ARCH.rules.)
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switch goarch {
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case "amd64", "arm64", "loong64", "mips", "mipsle", "mips64", "mips64le", "ppc64", "ppc64le", "riscv64", "s390x":
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return true
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default:
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return false
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}
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}
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type TypeAssert struct {
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Cache *TypeAssertCache
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Inter *InterfaceType
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CanFail bool
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}
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type TypeAssertCache struct {
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Mask uintptr
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Entries [1]TypeAssertCacheEntry
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}
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type TypeAssertCacheEntry struct {
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// type of source value (a *runtime._type)
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Typ uintptr
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// itab to use for result (a *runtime.itab)
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// nil if CanFail is set and conversion would fail.
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Itab uintptr
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}
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