[PowerPC] Update P9 vector costs for insert/extract element

The PPC vector cost model values for insert/extract element reflect older
processors that lacked vector insert/extract and move-to/move-from VSR
instructions.  Update getVectorInstrCost to give appropriate values for when
the newer instructions are present.

Differential Revision: https://reviews.llvm.org/D60160

llvm-svn: 359313

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
index 6185355f419..1fdaec076b1 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
@@ -412,6 +412,35 @@ int PPCTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
       return 0;
 
     return Cost;
+
+  } else if (Val->getScalarType()->isIntegerTy() && Index != -1U) {
+    if (ST->hasP9Altivec()) {
+      if (ISD == ISD::INSERT_VECTOR_ELT)
+        // A move-to VSR and a permute/insert.  Assume vector operation cost
+        // for both (cost will be 2x on P9).
+        return vectorCostAdjustment(2, Opcode, Val, nullptr);
+
+      // It's an extract.  Maybe we can do a cheap move-from VSR.
+      unsigned EltSize = Val->getScalarSizeInBits();
+      if (EltSize == 64) {
+        unsigned MfvsrdIndex = ST->isLittleEndian() ? 1 : 0;
+        if (Index == MfvsrdIndex)
+          return 1;
+      } else if (EltSize == 32) {
+        unsigned MfvsrwzIndex = ST->isLittleEndian() ? 2 : 1;
+        if (Index == MfvsrwzIndex)
+          return 1;
+      }
+
+      // We need a vector extract (or mfvsrld).  Assume vector operation cost.
+      // The cost of the load constant for a vector extract is disregarded
+      // (invariant, easily schedulable).
+      return vectorCostAdjustment(1, Opcode, Val, nullptr);
+      
+    } else if (ST->hasDirectMove())
+      // Assume permute has standard cost.
+      // Assume move-to/move-from VSR have 2x standard cost.
+      return 3;
   }
 
   // Estimated cost of a load-hit-store delay.  This was obtained