[PATCH] D76124: [TTI] Remove getOperationCost

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

Sanity check: i believe, as per `llvm::TargetTransformInfo::getInstructionCost()`,
there are three cost-models:

- throughput model (`getInstructionThroughput()`)
- latency model (`getInstructionLatency()`)
- size model (`getUserCost()`)

I'm not sure what `getOperationCost()` is supposed to represent,
so i'm not sure how it's code should be redistributed should it be deleted.



================
Comment at: llvm/include/llvm/Analysis/TargetTransformInfo.h:281
   /// This can estimate the cost of either a ConstantExpr or Instruction when
-  /// lowered. It has two primary advantages over the \c getOperationCost and
-  /// \c getGEPCost above, and one significant disadvantage: it can only be
-  /// used when the IR construct has already been formed.
+  /// lowered. It has two primary advantages over the \c getGEPCost above,
+  /// and one significant disadvantage: it can only be used when the IR
----------------
\c get*Cost

this isn't specific to getGEPCost at all


================
Comment at: llvm/include/llvm/Analysis/TargetTransformInfoImpl.h:869-872
+    case Instruction::Freeze:
+      // Freeze operation is free because it should be lowered into a register
+      // use without any register copy in assembly code.
+      return TTI::TCC_Free;
----------------
This is unreachable


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https://reviews.llvm.org/D76124