Loop Strength Reduce: Scaling factor cost.

Account for the cost of scaling factor in Loop Strength Reduce when rating the
formulae. This uses a target hook.

The default implementation of the hook is: if the addressing mode is legal, the
scaling factor is free.

<rdar://problem/13806271>

llvm-svn: 183045

1 files changed, 14 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp b/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
index 4a99184f5ee..92a5bb70f43 100644
--- a/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
+++ b/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
@@ -71,6 +71,9 @@ public:
   virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
                                      int64_t BaseOffset, bool HasBaseReg,
                                      int64_t Scale) const;
+  virtual int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
+                                   int64_t BaseOffset, bool HasBaseReg,
+                                   int64_t Scale) const;
   virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const;
   virtual bool isTypeLegal(Type *Ty) const;
   virtual unsigned getJumpBufAlignment() const;
@@ -139,6 +142,17 @@ bool BasicTTI::isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
   return TLI->isLegalAddressingMode(AM, Ty);
 }
 
+int BasicTTI::getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
+                                   int64_t BaseOffset, bool HasBaseReg,
+                                   int64_t Scale) const {
+  TargetLoweringBase::AddrMode AM;
+  AM.BaseGV = BaseGV;
+  AM.BaseOffs = BaseOffset;
+  AM.HasBaseReg = HasBaseReg;
+  AM.Scale = Scale;
+  return TLI->getScalingFactorCost(AM, Ty);
+}
+
 bool BasicTTI::isTruncateFree(Type *Ty1, Type *Ty2) const {
   return TLI->isTruncateFree(Ty1, Ty2);
 }