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| -rw-r--r-- | lib/Target/README.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index f39d8b2..623c86f 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -610,6 +610,14 @@ pointer parameters for alias analysis. Some ideas: arguments when the function is inlined. These functions can be inferred by various analysis passes such as the -globalsmodrefaa pass. +globalsmodrefaa pass. Note that getting #2 right is actually really tricky. +Consider this code: + +struct S; S G; +void caller(S byvalarg) { G.field = 1; ... } +void callee() { caller(G); } + +The fact that the caller does not modify byval arg is not enough, we need +to know that it doesn't modify G either. This is very tricky. //===---------------------------------------------------------------------===// |