diff options
Diffstat (limited to 'llvm/include/llvm/Use.h')
| -rw-r--r-- | llvm/include/llvm/Use.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/llvm/include/llvm/Use.h b/llvm/include/llvm/Use.h index 53df699e703..489dbc50a04 100644 --- a/llvm/include/llvm/Use.h +++ b/llvm/include/llvm/Use.h @@ -11,6 +11,15 @@ // instruction or some other User instance which refers to a Value. The Use // class keeps the "use list" of the referenced value up to date. // +// Pointer tagging is used to efficiently find the User corresponding +// to a Use without having to store a User pointer in every Use. A +// User is preceded in memory by all the Uses corresponding to its +// operands, and the low bits of one of the fields (Prev) of the Use +// class are used to encode offsets to be able to find that User given +// a pointer to any Use. For details, see: +// +// http://www.llvm.org/docs/ProgrammersManual.html#UserLayout +// //===----------------------------------------------------------------------===// #ifndef LLVM_USE_H |
