[llvm] r330834 - [CostModel][X86] Recursive call for cost of imul for packed v16i16 constant shift left.

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Wed Apr 25 08:22:03 2018
New Revision: 330834

URL: http://llvm.org/viewvc/llvm-project?rev=330834&view=rev
Log:
[CostModel][X86] Recursive call for cost of imul for packed v16i16 constant shift left.

Don't just assume cost = 1.

Modified:
    llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp

Modified: llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp?rev=330834&r1=330833&r2=330834&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp Wed Apr 25 08:22:03 2018
@@ -492,7 +492,9 @@ int X86TTIImpl::getArithmeticInstrCost(
          Op2Info == TargetTransformInfo::OK_NonUniformConstantValue))
       // On AVX2, a packed v16i16 shift left by a constant build_vector
       // is lowered into a vector multiply (vpmullw).
-      return LT.first;
+      return getArithmeticInstrCost(Instruction::Mul, Ty, Op1Info, Op2Info,
+                                    TargetTransformInfo::OP_None,
+                                    TargetTransformInfo::OP_None);
 
     if (const auto *Entry = CostTableLookup(AVX2ShiftCostTable, ISD, LT.second))
       return LT.first * Entry->Cost;