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| -rw-r--r-- | llvm/docs/AliasAnalysis.rst | 2 | ||||
| -rw-r--r-- | llvm/docs/LangRef.rst | 10 |
2 files changed, 11 insertions, 1 deletions
diff --git a/llvm/docs/AliasAnalysis.rst b/llvm/docs/AliasAnalysis.rst index 02b749ffb91..e201333f300 100644 --- a/llvm/docs/AliasAnalysis.rst +++ b/llvm/docs/AliasAnalysis.rst @@ -136,7 +136,7 @@ be overlapping in some way, but do not start at the same address. The ``MustAlias`` response may only be returned if the two memory objects are guaranteed to always start at exactly the same location. A ``MustAlias`` -response implies that the pointers compare equal. +response does not imply that the pointers compare equal. The ``getModRefInfo`` methods ----------------------------- diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst index c65c9eef776..1d0b9068d31 100644 --- a/llvm/docs/LangRef.rst +++ b/llvm/docs/LangRef.rst @@ -5121,6 +5121,16 @@ Examples: !0 = !{!"magic ptr"} !1 = !{!"other ptr"} +The invariant.group metadata must be dropped when replacing one pointer by +another based on aliasing information. This is because invariant.group is tied +to the SSA value of the pointer operand. + +.. code-block:: llvm + %v = load i8, i8* %x, !invariant.group !0 + ; if %x mustalias %y then we can replace the above instruction with + %v = load i8, i8* %y + + '``type``' Metadata ^^^^^^^^^^^^^^^^^^^ |
