diff options
Diffstat (limited to 'tensorflow/compiler/xla/service/copy_insertion.cc')
| -rw-r--r-- | tensorflow/compiler/xla/service/copy_insertion.cc | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/tensorflow/compiler/xla/service/copy_insertion.cc b/tensorflow/compiler/xla/service/copy_insertion.cc index 36fb9b43aa..3e39c1bab1 100644 --- a/tensorflow/compiler/xla/service/copy_insertion.cc +++ b/tensorflow/compiler/xla/service/copy_insertion.cc @@ -312,7 +312,7 @@ Status AddCopiesForWhile(const HloAliasAnalysis& alias_analysis, return Status::OK(); } -// We add copies for all the indices of the true and false computaiton roots, +// We add copies for all the indices of the true and false computation roots, // in order to resolve interference. We later rely on the CopyRemover to drop // the unnecessary ones. Status AddCopiesForConditional(const HloAliasAnalysis& alias_analysis, @@ -648,7 +648,12 @@ class CopyRemover { // We can only perform copy elision if the resulting merged values have // totally ordered live ranges; otherwise the merged buffer would have // live range interference. - if (IsHead(*dest)) { + if (src->next == dest) { + // In the process of eliding copies, its possible for a copy to have the + // same source and destination buffer. In this case, the copy can be + // safely removed. + VLOG(2) << copy->name() << " source and destination buffers are same."; + } else if (IsHead(*dest)) { // The copy copies an arbitrary value in the source buffer (call it s_x) // and defines d_0, the first value in the destination buffer. After // merging, the values in the combined buffer must be strictly ordered |