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| author | Cuong Manh Le <cuong.manhle.vn@gmail.com> | 2022-08-03 15:14:25 +0700 |
|---|---|---|
| committer | Cuong Manh Le <cuong.manhle.vn@gmail.com> | 2022-08-08 14:12:01 +0000 |
| commit | 3ea3d0e8a7f4e2bfa96535aafb6bd802d2907808 (patch) | |
| tree | caec85cfb9ce0ec05bfd30c5b1a880be249855f4 /src | |
| parent | 9463638ca883f07467ad8e294cf3ba7f7b175eb2 (diff) | |
| download | go-3ea3d0e8a7f4e2bfa96535aafb6bd802d2907808.tar.xz | |
cmd/compile: correct alignment of atomic.Int64
Same as CL 417555, but for cmd/compile.
Fixes #54220
Change-Id: I4cc6deaf0a87c952f636888b4ab73f81a44bfebd
Reviewed-on: https://go-review.googlesource.com/c/go/+/420975
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/noder/sizes.go | 11 | ||||
| -rw-r--r-- | src/cmd/compile/internal/types2/sizes.go | 4 |
2 files changed, 13 insertions, 2 deletions
diff --git a/src/cmd/compile/internal/noder/sizes.go b/src/cmd/compile/internal/noder/sizes.go index 9ba0e509d7..7820746db1 100644 --- a/src/cmd/compile/internal/noder/sizes.go +++ b/src/cmd/compile/internal/noder/sizes.go @@ -25,6 +25,17 @@ func (s *gcSizes) Alignof(T types2.Type) int64 { // is the same as unsafe.Alignof(x[0]), but at least 1." return s.Alignof(t.Elem()) case *types2.Struct: + if t.NumFields() == 0 && types2.IsSyncAtomicAlign64(T) { + // Special case: sync/atomic.align64 is an + // empty struct we recognize as a signal that + // the struct it contains must be + // 64-bit-aligned. + // + // This logic is equivalent to the logic in + // cmd/compile/internal/types/size.go:calcStructOffset + return 8 + } + // spec: "For a variable x of struct type: unsafe.Alignof(x) // is the largest of the values unsafe.Alignof(x.f) for each // field f of x, but at least 1." diff --git a/src/cmd/compile/internal/types2/sizes.go b/src/cmd/compile/internal/types2/sizes.go index 4da309461f..c99a12b2e9 100644 --- a/src/cmd/compile/internal/types2/sizes.go +++ b/src/cmd/compile/internal/types2/sizes.go @@ -53,7 +53,7 @@ func (s *StdSizes) Alignof(T Type) int64 { // is the same as unsafe.Alignof(x[0]), but at least 1." return s.Alignof(t.elem) case *Struct: - if len(t.fields) == 0 && isSyncAtomicAlign64(T) { + if len(t.fields) == 0 && IsSyncAtomicAlign64(T) { // Special case: sync/atomic.align64 is an // empty struct we recognize as a signal that // the struct it contains must be @@ -104,7 +104,7 @@ func (s *StdSizes) Alignof(T Type) int64 { return a } -func isSyncAtomicAlign64(T Type) bool { +func IsSyncAtomicAlign64(T Type) bool { named, ok := T.(*Named) if !ok { return false |