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cmd/compile: don't generate newobject call for 0-sized types
Emit &runtime.zerobase instead of a call to newobject for allocations of zero sized objects in walk.go. Fixes #29446 Change-Id: I11b67981d55009726a17c2e582c12ce0c258682e Reviewed-on: https://go-review.googlesource.com/c/155840 Run-TryBot: Iskander Sharipov <quasilyte@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Keith Randall <khr@golang.org>
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// asmcheck | ||
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// 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. | ||
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// These tests check that allocating a 0-size object does not | ||
// introduce a call to runtime.newobject. | ||
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package codegen | ||
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func zeroAllocNew1() *struct{} { | ||
// 386:-`CALL\truntime\.newobject` | ||
// amd64:-`CALL\truntime\.newobject` | ||
// arm:-`CALL\truntime\.newobject` | ||
// arm64:-`CALL\truntime\.newobject` | ||
return new(struct{}) | ||
} | ||
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func zeroAllocNew2() *[0]int { | ||
// 386:-`CALL\truntime\.newobject` | ||
// amd64:-`CALL\truntime\.newobject` | ||
// arm:-`CALL\truntime\.newobject` | ||
// arm64:-`CALL\truntime\.newobject` | ||
return new([0]int) | ||
} | ||
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func zeroAllocSliceLit() []int { | ||
// 386:-`CALL\truntime\.newobject` | ||
// amd64:-`CALL\truntime\.newobject` | ||
// arm:-`CALL\truntime\.newobject` | ||
// arm64:-`CALL\truntime\.newobject` | ||
return []int{} | ||
} |