go/test/codegen/maps.go

// asmcheck

// Copyright 2018 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.

package codegen

// This file contains code generation tests related to the handling of
// map types.

// ------------------- //
//     Access Const    //
// ------------------- //

// Direct use of constants in fast map access calls (Issue #19015).

func AccessInt1(m map[int]int) int {
	// amd64:"MOVQ\t[$]5"
	return m[5]
}

func AccessInt2(m map[int]int) bool {
	// amd64:"MOVQ\t[$]5"
	_, ok := m[5]
	return ok
}

func AccessString1(m map[string]int) int {
	// amd64:`.*"abc"`
	return m["abc"]
}

func AccessString2(m map[string]int) bool {
	// amd64:`.*"abc"`
	_, ok := m["abc"]
	return ok
}

// ------------------- //
//     Map Clear       //
// ------------------- //

// Optimization of map clear idiom (Issue #20138).

func MapClearReflexive(m map[int]int) {
	// amd64:`.*runtime\.mapclear`
	// amd64:-`.*runtime\.mapiterinit`
	for k := range m {
		delete(m, k)
	}
}

func MapClearIndirect(m map[int]int) {
	s := struct{ m map[int]int }{m: m}
	// amd64:`.*runtime\.mapclear`
	// amd64:-`.*runtime\.mapiterinit`
	for k := range s.m {
		delete(s.m, k)
	}
}

func MapClearPointer(m map[*byte]int) {
	// amd64:`.*runtime\.mapclear`
	// amd64:-`.*runtime\.mapiterinit`
	for k := range m {
		delete(m, k)
	}
}

func MapClearNotReflexive(m map[float64]int) {
	// amd64:`.*runtime\.mapiterinit`
	// amd64:-`.*runtime\.mapclear`
	for k := range m {
		delete(m, k)
	}
}

func MapClearInterface(m map[interface{}]int) {
	// amd64:`.*runtime\.mapiterinit`
	// amd64:-`.*runtime\.mapclear`
	for k := range m {
		delete(m, k)
	}
}

func MapClearSideEffect(m map[int]int) int {
	k := 0
	// amd64:`.*runtime\.mapiterinit`
	// amd64:-`.*runtime\.mapclear`
	for k = range m {
		delete(m, k)
	}
	return k
}