[LV] Bundle sub reductions into VPExpressionRecipeusers/SamTebbs33/expression-recipe-sub

This PR bundles sub reductions into the VPExpressionRecipe class and
adjusts the cost functions to take the negation into account.

1 files changed, 32 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 318e8171e098..c20b1920c379 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -2672,13 +2672,17 @@ InstructionCost VPExpressionRecipe::computeCost(ElementCount VF,
         RedTy, SrcVecTy, std::nullopt, Ctx.CostKind);
   }
   case ExpressionTypes::MulAccReduction:
-    return Ctx.TTI.getMulAccReductionCost(false, RedTy, SrcVecTy, Ctx.CostKind);
+    return Ctx.TTI.getMulAccReductionCost(false, RedTy, SrcVecTy, false,
+                                          Ctx.CostKind);
 
-  case ExpressionTypes::ExtMulAccReduction:
+  case ExpressionTypes::ExtNegatedMulAccReduction:
+  case ExpressionTypes::ExtMulAccReduction: {
+    bool Negated = ExpressionType == ExpressionTypes::ExtNegatedMulAccReduction;
     return Ctx.TTI.getMulAccReductionCost(
         cast<VPWidenCastRecipe>(ExpressionRecipes.front())->getOpcode() ==
             Instruction::ZExt,
-        RedTy, SrcVecTy, Ctx.CostKind);
+        RedTy, SrcVecTy, Negated, Ctx.CostKind);
+  }
   }
   llvm_unreachable("Unknown VPExpressionRecipe::ExpressionTypes enum");
 }
@@ -2725,6 +2729,31 @@ void VPExpressionRecipe::print(raw_ostream &O, const Twine &Indent,
     O << ")";
     break;
   }
+  case ExpressionTypes::ExtNegatedMulAccReduction: {
+    getOperand(getNumOperands() - 1)->printAsOperand(O, SlotTracker);
+    O << " + ";
+    O << "reduce."
+      << Instruction::getOpcodeName(
+             RecurrenceDescriptor::getOpcode(Red->getRecurrenceKind()))
+      << " (sub (0, mul";
+    auto *Mul = cast<VPWidenRecipe>(ExpressionRecipes[2]);
+    Mul->printFlags(O);
+    O << "(";
+    getOperand(0)->printAsOperand(O, SlotTracker);
+    auto *Ext0 = cast<VPWidenCastRecipe>(ExpressionRecipes[0]);
+    O << " " << Instruction::getOpcodeName(Ext0->getOpcode()) << " to "
+      << *Ext0->getResultType() << "), (";
+    getOperand(1)->printAsOperand(O, SlotTracker);
+    auto *Ext1 = cast<VPWidenCastRecipe>(ExpressionRecipes[1]);
+    O << " " << Instruction::getOpcodeName(Ext1->getOpcode()) << " to "
+      << *Ext1->getResultType() << ")";
+    if (Red->isConditional()) {
+      O << ", ";
+      Red->getCondOp()->printAsOperand(O, SlotTracker);
+    }
+    O << "))";
+    break;
+  }
   case ExpressionTypes::MulAccReduction:
   case ExpressionTypes::ExtMulAccReduction: {
     getOperand(getNumOperands() - 1)->printAsOperand(O, SlotTracker);