Change CaptureTracking to pass a Use* instead of a Value* when a value is

captured. This allows the tracker to look at the specific use, which may be
especially interesting for function calls.

Use this to fix 'nocapture' deduction in FunctionAttrs. The existing one does
not iterate until a fixpoint and does not guarantee that it produces the same
result regardless of iteration order. The new implementation builds up a graph
of how arguments are passed from function to function, and uses a bottom-up walk
on the argument-SCCs to assign nocapture. This gets us nocapture more often, and
does so rather efficiently and independent of iteration order.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147327 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 4 deletions

diff --git a/include/llvm/Analysis/CaptureTracking.h b/include/llvm/Analysis/CaptureTracking.h
index 01eca6041e..f2e72535cd 100644
--- a/include/llvm/Analysis/CaptureTracking.h
+++ b/include/llvm/Analysis/CaptureTracking.h
@@ -50,10 +50,10 @@ namespace llvm {
     /// U->getUser() is always an Instruction.
     virtual bool shouldExplore(Use *U) = 0;
 
-    /// captured - The instruction I captured the pointer. Return true to
-    /// stop the traversal or false to continue looking for more capturing
-    /// instructions.
-    virtual bool captured(Instruction *I) = 0;
+    /// captured - Information about the pointer was captured by the user of
+    /// use U. Return true to stop the traversal or false to continue looking
+    /// for more capturing instructions.
+    virtual bool captured(Use *U) = 0;
   };
 
   /// PointerMayBeCaptured - Visit the value and the values derived from it and