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| author | Austin Clements <austin@google.com> | 2016-03-16 18:22:58 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2016-03-16 22:42:45 +0000 |
| commit | 3e54ca9a4624fda0bcd76192aa529e826ef12b4f (patch) | |
| tree | 6a36221aef31071d3b57f24c5832c9d4e94fc170 /src/cmd | |
| parent | 4e75932cf7148c6ed10f93bbc07a79a7f89e8bd2 (diff) | |
| download | go-3e54ca9a4624fda0bcd76192aa529e826ef12b4f.tar.xz | |
cmd/compile: omit write barrier when assigning global function
Currently we generate write barriers when the right side of an
assignment is a global function. This doesn't fall into the existing
case of storing an address of a global because we haven't lowered the
function to a pointer yet.
This write barrier is unnecessary, so eliminate it.
Fixes #13901.
Change-Id: Ibc10e00a8803db0fd75224b66ab94c3737842a79
Reviewed-on: https://go-review.googlesource.com/20772
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/cmd')
| -rw-r--r-- | src/cmd/compile/internal/gc/walk.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go index b4c38ec12b..69c8390fe0 100644 --- a/src/cmd/compile/internal/gc/walk.go +++ b/src/cmd/compile/internal/gc/walk.go @@ -2140,6 +2140,12 @@ func needwritebarrier(l *Node, r *Node) bool { return false } + // No write barrier for storing global function, which is live + // no matter what. + if r.Op == ONAME && r.Class == PFUNC { + return false + } + // Otherwise, be conservative and use write barrier. return true } |