diff options
| author | Austin Clements <austin@google.com> | 2017-11-02 12:37:25 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2017-11-06 21:07:57 +0000 |
| commit | 3a446d865226f2141208deb21ea2d829609c3cf6 (patch) | |
| tree | 2f5924da5e7b77efa62b189ae0f23190098da09a /test/notinheap3.go | |
| parent | 0838c0f2f9fd45f527c4be8e27589eed22e0e559 (diff) | |
| download | go-3a446d865226f2141208deb21ea2d829609c3cf6.tar.gz go-3a446d865226f2141208deb21ea2d829609c3cf6.zip | |
cmd/compile: []T where T is go:notinheap does not need write barriers
Currently, assigning a []T where T is a go:notinheap type generates an
unnecessary write barrier for storing the slice pointer.
This fixes this by teaching HasHeapPointer that this type does not
have a heap pointer, and tweaking the lowering of slice assignments so
the pointer store retains the correct type rather than simply lowering
it to a *uint8 store.
Change-Id: I8bf7c66e64a7fefdd14f2bd0de8a5a3596340bab
Reviewed-on: https://go-review.googlesource.com/76027
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'test/notinheap3.go')
| -rw-r--r-- | test/notinheap3.go | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/test/notinheap3.go b/test/notinheap3.go index b37d73df6d..d48c2a0cc9 100644 --- a/test/notinheap3.go +++ b/test/notinheap3.go @@ -10,11 +10,13 @@ package p type t1 struct { x *nih + s []nih y [1024]byte // Prevent write decomposition } type t2 struct { x *ih + s []ih y [1024]byte } @@ -37,8 +39,10 @@ var ( func f() { // Test direct writes - v1.x = nil // no barrier - v2.x = nil // ERROR "write barrier" + v1.x = nil // no barrier + v2.x = nil // ERROR "write barrier" + v1.s = []nih(nil) // no barrier + v2.s = []ih(nil) // ERROR "write barrier" } func g() { |