Use getIntrinsicInstrCost for FCanonicalize

Author: Your Name

llvm/include/llvm/CodeGen/BasicTTIImpl.h

@@ -2783,15 +2783,18 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
       //    ARG0 = fcanonicalize ARG0, ARG0  // to quiet ARG0
       //    ARG1 = fcanonicalize ARG1, ARG1  // to quiet ARG1
       //    RESULT = MAXNUM_IEEE ARG0, ARG1  // or MINNUM_IEEE
-      // Here fcanonicalize may be FMAXNUM_IEEE or FMINNUM_IEEE varies by
-      // architecture.
       // FIXME: In LangRef, we claimed FMAXNUM has the same behaviour of
       //        FMAXNUM_IEEE, while the backend hasn't migrated the code yet.
       //        Finally, we will remove FMAXNUM_IEEE and FMINNUM_IEEE.
-      // All known platforms have both FMAXNUM_IEEE and FMINNUM_IEEE, so we
-      // check MAX only.
-      if (TLI->isOperationLegalOrPromote(ISD::FMAXNUM_IEEE, LT.second))
-        return LT.first * 3;
+      int IeeeISD =
+          IID == Intrinsic::maximumnum ? ISD::FMAXNUM_IEEE : ISD::FMINNUM_IEEE;
+      if (TLI->isOperationLegalOrPromote(IeeeISD, LT.second)) {
+        IntrinsicCostAttributes FCanonicalizeAttrs(Intrinsic::canonicalize,
+                                                   RetTy, Tys[0]);
+        InstructionCost FCanonicalizeCost =
+            thisT()->getIntrinsicInstrCost(FCanonicalizeAttrs, CostKind);
+        return LT.first + FCanonicalizeCost * 2;
+      }
       break;
     }
     default: