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go/test/codegen/slices.go
Keith Randall c2a9c55823 cmd/compile: optimize unsafe.Slice generated code 
We don't need a multiply when the element type is size 0 or 1.

The panic functions don't return, so we don't need any post-call
code (register restores, etc.).

Change-Id: I0dcea5df56d29d7be26554ddca966b3903c672e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/419754
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2022-08-08 17:36:47 +00:00

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// 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
import "unsafe"
// This file contains code generation tests related to the handling of
// slice types.
// ------------------ //
// Clear //
// ------------------ //
// Issue #5373 optimize memset idiom
func SliceClear(s []int) []int {
// amd64:`.*memclrNoHeapPointers`
for i := range s {
s[i] = 0
}
return s
}
func SliceClearPointers(s []*int) []*int {
// amd64:`.*memclrHasPointers`
for i := range s {
s[i] = nil
}
return s
}
// ------------------ //
// Extension //
// ------------------ //
// Issue #21266 - avoid makeslice in append(x, make([]T, y)...)
func SliceExtensionConst(s []int) []int {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:-`.*runtime\.panicmakeslicelen`
return append(s, make([]int, 1<<2)...)
}
func SliceExtensionConstInt64(s []int) []int {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:-`.*runtime\.panicmakeslicelen`
return append(s, make([]int, int64(1<<2))...)
}
func SliceExtensionConstUint64(s []int) []int {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:-`.*runtime\.panicmakeslicelen`
return append(s, make([]int, uint64(1<<2))...)
}
func SliceExtensionConstUint(s []int) []int {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:-`.*runtime\.panicmakeslicelen`
return append(s, make([]int, uint(1<<2))...)
}
func SliceExtensionPointer(s []*int, l int) []*int {
// amd64:`.*runtime\.memclrHasPointers`
// amd64:-`.*runtime\.makeslice`
return append(s, make([]*int, l)...)
}
func SliceExtensionVar(s []byte, l int) []byte {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
return append(s, make([]byte, l)...)
}
func SliceExtensionVarInt64(s []byte, l int64) []byte {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:`.*runtime\.panicmakeslicelen`
return append(s, make([]byte, l)...)
}
func SliceExtensionVarUint64(s []byte, l uint64) []byte {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:`.*runtime\.panicmakeslicelen`
return append(s, make([]byte, l)...)
}
func SliceExtensionVarUint(s []byte, l uint) []byte {
// amd64:`.*runtime\.memclrNoHeapPointers`
// amd64:-`.*runtime\.makeslice`
// amd64:`.*runtime\.panicmakeslicelen`
return append(s, make([]byte, l)...)
}
func SliceExtensionInt64(s []int, l64 int64) []int {
// 386:`.*runtime\.makeslice`
// 386:-`.*runtime\.memclr`
return append(s, make([]int, l64)...)
}
// ------------------ //
// Make+Copy //
// ------------------ //
// Issue #26252 - avoid memclr for make+copy
func SliceMakeCopyLen(s []int) []int {
// amd64:`.*runtime\.mallocgc`
// amd64:`.*runtime\.memmove`
// amd64:-`.*runtime\.makeslice`
a := make([]int, len(s))
copy(a, s)
return a
}
func SliceMakeCopyLenPtr(s []*int) []*int {
// amd64:`.*runtime\.makeslicecopy`
// amd64:-`.*runtime\.makeslice\(`
// amd64:-`.*runtime\.typedslicecopy
a := make([]*int, len(s))
copy(a, s)
return a
}
func SliceMakeCopyConst(s []int) []int {
// amd64:`.*runtime\.makeslicecopy`
// amd64:-`.*runtime\.makeslice\(`
// amd64:-`.*runtime\.memmove`
a := make([]int, 4)
copy(a, s)
return a
}
func SliceMakeCopyConstPtr(s []*int) []*int {
// amd64:`.*runtime\.makeslicecopy`
// amd64:-`.*runtime\.makeslice\(`
// amd64:-`.*runtime\.typedslicecopy
a := make([]*int, 4)
copy(a, s)
return a
}
func SliceMakeCopyNoOptNoDeref(s []*int) []*int {
a := new([]*int)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
*a = make([]*int, 4)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.typedslicecopy`
copy(*a, s)
return *a
}
func SliceMakeCopyNoOptNoVar(s []*int) []*int {
a := make([][]*int, 1)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a[0] = make([]*int, 4)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.typedslicecopy`
copy(a[0], s)
return a[0]
}
func SliceMakeCopyNoOptBlank(s []*int) []*int {
var a []*int
// amd64:-`.*runtime\.makeslicecopy`
_ = make([]*int, 4)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.typedslicecopy`
copy(a, s)
return a
}
func SliceMakeCopyNoOptNoMake(s []*int) []*int {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:-`.*runtime\.objectnew`
a := *new([]*int)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.typedslicecopy`
copy(a, s)
return a
}
func SliceMakeCopyNoOptNoHeapAlloc(s []*int) int {
// amd64:-`.*runtime\.makeslicecopy`
a := make([]*int, 4)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.typedslicecopy`
copy(a, s)
return cap(a)
}
func SliceMakeCopyNoOptNoCap(s []*int) []*int {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]*int, 0, 4)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.typedslicecopy`
copy(a, s)
return a
}
func SliceMakeCopyNoOptNoCopy(s []*int) []*int {
copy := func(x, y []*int) {}
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]*int, 4)
// amd64:-`.*runtime\.makeslicecopy`
copy(a, s)
return a
}
func SliceMakeCopyNoOptWrongOrder(s []*int) []*int {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]*int, 4)
// amd64:`.*runtime\.typedslicecopy`
// amd64:-`.*runtime\.makeslicecopy`
copy(s, a)
return a
}
func SliceMakeCopyNoOptWrongAssign(s []*int) []*int {
var a []*int
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
s = make([]*int, 4)
// amd64:`.*runtime\.typedslicecopy`
// amd64:-`.*runtime\.makeslicecopy`
copy(a, s)
return s
}
func SliceMakeCopyNoOptCopyLength(s []*int) (int, []*int) {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]*int, 4)
// amd64:`.*runtime\.typedslicecopy`
// amd64:-`.*runtime\.makeslicecopy`
n := copy(a, s)
return n, a
}
func SliceMakeCopyNoOptSelfCopy(s []*int) []*int {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]*int, 4)
// amd64:`.*runtime\.typedslicecopy`
// amd64:-`.*runtime\.makeslicecopy`
copy(a, a)
return a
}
func SliceMakeCopyNoOptTargetReference(s []*int) []*int {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]*int, 4)
// amd64:`.*runtime\.typedslicecopy`
// amd64:-`.*runtime\.makeslicecopy`
copy(a, s[:len(a)])
return a
}
func SliceMakeCopyNoOptCap(s []int) []int {
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.makeslice\(`
a := make([]int, len(s), 9)
// amd64:-`.*runtime\.makeslicecopy`
// amd64:`.*runtime\.memmove`
copy(a, s)
return a
}
func SliceMakeCopyNoMemmoveDifferentLen(s []int) []int {
// amd64:`.*runtime\.makeslicecopy`
// amd64:-`.*runtime\.memmove`
a := make([]int, len(s)-1)
// amd64:-`.*runtime\.memmove`
copy(a, s)
return a
}
// ---------------------- //
// Nil check of &s[0] //
// ---------------------- //
// See issue 30366
func SliceNilCheck(s []int) {
p := &s[0]
// amd64:-`TESTB`
_ = *p
}
// ---------------------- //
// Init slice literal //
// ---------------------- //
// See issue 21561
func InitSmallSliceLiteral() []int {
// amd64:`MOVQ\t[$]42`
return []int{42}
}
func InitNotSmallSliceLiteral() []int {
// amd64:`LEAQ\t.*stmp_`
return []int{
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
42,
}
}
// --------------------------------------- //
// Test PPC64 SUBFCconst folding rules //
// triggered by slice operations. //
// --------------------------------------- //
func SliceWithConstCompare(a []int, b int) []int {
var c []int = []int{1, 2, 3, 4, 5}
if b+len(a) < len(c) {
// ppc64le:-"NEG"
// ppc64:-"NEG"
return c[b:]
}
return a
}
func SliceWithSubtractBound(a []int, b int) []int {
// ppc64le:"SUBC",-"NEG"
// ppc64:"SUBC",-"NEG"
return a[(3 - b):]
}
// --------------------------------------- //
// Code generation for unsafe.Slice //
// --------------------------------------- //
func Slice1(p *byte, i int) []byte {
// amd64:-"MULQ"
return unsafe.Slice(p, i)
}
func Slice0(p *struct{}, i int) []struct{} {
// amd64:-"MULQ"
return unsafe.Slice(p, i)
}
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