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| author | Chris Lattner <sabre@nondot.org> | 2008-01-12 18:58:46 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2008-01-12 18:58:46 +0000 |
| commit | afb514a7b49c72f359155319deab946f2196fcbc (patch) | |
| tree | cfe7cf8ec3a7053e32204b0c7ff9f509203ab5c4 /llvm/lib/Target | |
| parent | 09dde6001df11ec681a7d537f356b4ae76e72eaf (diff) | |
| download | bcm5719-llvm-afb514a7b49c72f359155319deab946f2196fcbc.tar.gz bcm5719-llvm-afb514a7b49c72f359155319deab946f2196fcbc.zip | |
clarify a note
llvm-svn: 45914
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/README.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/llvm/lib/Target/README.txt b/llvm/lib/Target/README.txt index f39d8b2a244..623c86f3555 100644 --- a/llvm/lib/Target/README.txt +++ b/llvm/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. //===---------------------------------------------------------------------===// |
