| // Copyright 2023 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // WARNING: Please avoid updating this file. If this file needs to be updated, |
| // then a new devirt.pprof file should be generated: |
| // |
| // $ cd $GOROOT/src/cmd/compile/internal/test/testdata/pgo/devirtualize/ |
| // $ go mod init example.com/pgo/devirtualize |
| // $ go test -bench=. -cpuprofile ./devirt.pprof |
| |
| package devirt |
| |
| import "example.com/pgo/devirtualize/mult" |
| |
| var sink int |
| |
| type Adder interface { |
| Add(a, b int) int |
| } |
| |
| type Add struct{} |
| |
| func (Add) Add(a, b int) int { |
| for i := 0; i < 1000; i++ { |
| sink++ |
| } |
| return a + b |
| } |
| |
| type Sub struct{} |
| |
| func (Sub) Add(a, b int) int { |
| for i := 0; i < 1000; i++ { |
| sink++ |
| } |
| return a - b |
| } |
| |
| // Exercise calls mostly a1 and m1. |
| // |
| //go:noinline |
| func Exercise(iter int, a1, a2 Adder, m1, m2 mult.Multiplier) { |
| for i := 0; i < iter; i++ { |
| a := a1 |
| m := m1 |
| if i%10 == 0 { |
| a = a2 |
| m = m2 |
| } |
| |
| // N.B. Profiles only distinguish calls on a per-line level, |
| // making the two calls ambiguous. However because the |
| // interfaces and implementations are mutually exclusive, |
| // devirtualization can still select the correct callee for |
| // each. |
| // |
| // If they were not mutually exclusive (for example, two Add |
| // calls), then we could not definitively select the correct |
| // callee. |
| sink += m.Multiply(42, a.Add(1, 2)) |
| } |
| } |
| |
| func init() { |
| // TODO: until https://golang.org/cl/497175 or similar lands, |
| // we need to create an explicit reference to callees |
| // in another package for devirtualization to work. |
| m := mult.Mult{} |
| m.Multiply(42, 0) |
| n := mult.NegMult{} |
| n.Multiply(42, 0) |
| } |