Add getUnrollingPreferences to TTI

Allow targets to customize the default behavior of the generic loop unrolling
transformation. This will be used by the PowerPC backend when targeting the A2
core (which is in-order with a deep pipeline), and using more aggressive
defaults is important.

llvm-svn: 189565

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp b/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
index d5340e60231..e1380b73e9e 100644
--- a/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
+++ b/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
@@ -84,6 +84,7 @@ public:
   virtual unsigned getJumpBufSize() const;
   virtual bool shouldBuildLookupTables() const;
   virtual bool haveFastSqrt(Type *Ty) const;
+  virtual bool getUnrollingPreferences(UnrollingPreferences &UP) const;
 
   /// @}
 
@@ -189,6 +190,10 @@ bool BasicTTI::haveFastSqrt(Type *Ty) const {
   return TLI->isTypeLegal(VT) && TLI->isOperationLegalOrCustom(ISD::FSQRT, VT);
 }
 
+bool BasicTTI::getUnrollingPreferences(UnrollingPreferences &) const {
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 //
 // Calls used by the vectorizers.