[NFC][TLI] Move `isLoadBitCastBeneficial()` implementation into source file

... so any change to it does not cause 700 source files to be recompiled.

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index fba60c8..37eb96e 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -2214,6 +2214,28 @@ int TargetLoweringBase::getDivRefinementSteps(EVT VT,
   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
 }
 
+bool TargetLoweringBase::isLoadBitCastBeneficial(
+    EVT LoadVT, EVT BitcastVT, const SelectionDAG &DAG,
+    const MachineMemOperand &MMO) const {
+  // Don't do if we could do an indexed load on the original type, but not on
+  // the new one.
+  if (!LoadVT.isSimple() || !BitcastVT.isSimple())
+    return true;
+
+  MVT LoadMVT = LoadVT.getSimpleVT();
+
+  // Don't bother doing this if it's just going to be promoted again later, as
+  // doing so might interfere with other combines.
+  if (getOperationAction(ISD::LOAD, LoadMVT) == Promote &&
+      getTypeToPromoteTo(ISD::LOAD, LoadMVT) == BitcastVT.getSimpleVT())
+    return false;
+
+  unsigned Fast = 0;
+  return allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), BitcastVT,
+                            MMO, &Fast) &&
+         Fast;
+}
+
 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
   MF.getRegInfo().freezeReservedRegs(MF);
 }