From c1050a8e54e1e1c06aa02ccf2b36c13a95666121 Mon Sep 17 00:00:00 2001 From: Iskander Sharipov Date: Fri, 28 Dec 2018 21:40:04 +0300 Subject: 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 TryBot-Result: Gobot Gobot Reviewed-by: Cherry Zhang Reviewed-by: Keith Randall --- test/codegen/alloc.go | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 test/codegen/alloc.go (limited to 'test/codegen') diff --git a/test/codegen/alloc.go b/test/codegen/alloc.go new file mode 100644 index 0000000000..31455fdabf --- /dev/null +++ b/test/codegen/alloc.go @@ -0,0 +1,34 @@ +// 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. + +// These tests check that allocating a 0-size object does not +// introduce a call to runtime.newobject. + +package codegen + +func zeroAllocNew1() *struct{} { + // 386:-`CALL\truntime\.newobject` + // amd64:-`CALL\truntime\.newobject` + // arm:-`CALL\truntime\.newobject` + // arm64:-`CALL\truntime\.newobject` + return new(struct{}) +} + +func zeroAllocNew2() *[0]int { + // 386:-`CALL\truntime\.newobject` + // amd64:-`CALL\truntime\.newobject` + // arm:-`CALL\truntime\.newobject` + // arm64:-`CALL\truntime\.newobject` + return new([0]int) +} + +func zeroAllocSliceLit() []int { + // 386:-`CALL\truntime\.newobject` + // amd64:-`CALL\truntime\.newobject` + // arm:-`CALL\truntime\.newobject` + // arm64:-`CALL\truntime\.newobject` + return []int{} +} -- cgit v1.3-5-g45d5