Add useAA() to TargetSubtargetInfo

There are several optional (off-by-default) features in CodeGen that can make
use of alias analysis. These features are important for generating code for
some kinds of cores (for example the (in-order) PPC A2 core). This adds a
useAA() function to TargetSubtargetInfo to allow these features to be enabled
by default on a per-subtarget basis.

Here is the first use of this function: To control the default of the
-enable-aa-sched-mi feature.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189563 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/include/llvm/Target/TargetSubtargetInfo.h b/include/llvm/Target/TargetSubtargetInfo.h
index b2d405d..2092aba 100644
--- a/include/llvm/Target/TargetSubtargetInfo.h
+++ b/include/llvm/Target/TargetSubtargetInfo.h
@@ -75,6 +75,10 @@ public:
   virtual void adjustSchedDependency(SUnit *def, SUnit *use,
                                      SDep& dep) const { }
 
+  /// \brief Enable use of alias analysis during code generation (during MI
+  /// scheduling, DAGCombine, etc.).
+  virtual bool useAA() const;
+
   /// \brief Reset the features for the subtarget.
   virtual void resetSubtargetFeatures(const MachineFunction *MF) { }
 };