[x86] add cost overrides for mul with overflow

I'm assuming the standard size integer instructions for this end up as something like:
mulq %rsi
seto %al

And the 'mul' generally has reciprocal throughput of 1 on typical implementations
(higher latency, but that's not handled here).
The default costs may end up much higher than that, and that's what we see in the test diffs.

Vector types are left as a 'TODO'.

Differential Revision: https://reviews.llvm.org/D90431

Author: rotateright

llvm/lib/Target/X86/X86TargetTransformInfo.cpp

@@ -2288,6 +2288,9 @@ int X86TTIImpl::getTypeBasedIntrinsicInstrCost(
   // CTLZ: llvm\test\CodeGen\X86\vector-lzcnt-*.ll
   // CTPOP: llvm\test\CodeGen\X86\vector-popcnt-*.ll
   // CTTZ: llvm\test\CodeGen\X86\vector-tzcnt-*.ll
+
+  // TODO: Overflow intrinsics (*ADDO, *SUBO, *MULO) with vector types are not
+  //       specialized in these tables yet.
   static const CostTblEntry AVX512CDCostTbl[] = {
     { ISD::CTLZ,       MVT::v8i64,   1 },
     { ISD::CTLZ,       MVT::v16i32,  1 },
@@ -2669,6 +2672,7 @@ int X86TTIImpl::getTypeBasedIntrinsicInstrCost(
     { ISD::CTPOP,      MVT::i64,    10 },
     { ISD::SADDO,      MVT::i64,     1 },
     { ISD::UADDO,      MVT::i64,     1 },
+    { ISD::UMULO,      MVT::i64,     2 }, // mulq + seto
   };
   static const CostTblEntry X86CostTbl[] = { // 32 or 64-bit targets
     { ISD::BITREVERSE, MVT::i32,    14 },
@@ -2689,6 +2693,9 @@ int X86TTIImpl::getTypeBasedIntrinsicInstrCost(
     { ISD::UADDO,      MVT::i32,     1 },
     { ISD::UADDO,      MVT::i16,     1 },
     { ISD::UADDO,      MVT::i8,      1 },
+    { ISD::UMULO,      MVT::i32,     2 }, // mul + seto
+    { ISD::UMULO,      MVT::i16,     2 },
+    { ISD::UMULO,      MVT::i8,      2 },
   };
 
   Type *RetTy = ICA.getReturnType();
@@ -2760,6 +2767,12 @@ int X86TTIImpl::getTypeBasedIntrinsicInstrCost(
     ISD = ISD::UADDO;
     OpTy = RetTy->getContainedType(0);
     break;
+  case Intrinsic::umul_with_overflow:
+  case Intrinsic::smul_with_overflow:
+    // SMULO has same costs so don't duplicate.
+    ISD = ISD::UMULO;
+    OpTy = RetTy->getContainedType(0);
+    break;
   }
 
   if (ISD != ISD::DELETED_NODE) {