[llvm] Enable LoopVectorizer interleaving for vectorized loops. (PR #184306)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-systemz

Author: Jonas Paulsson (JonPsson1)

<details>
<summary>Changes</summary>

This reduced the number of tiny loops and helps performance.

@<!-- -->uweigand @<!-- -->dominik-steenken 

---
Full diff: https://github.com/llvm/llvm-project/pull/184306.diff


2 Files Affected:

- (modified) llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp (+14) 
- (modified) llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h (+4) 


``````````diff
diff --git a/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp b/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
index 4322773f4afd6..5c71aa23ed1bc 100644
--- a/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
@@ -478,6 +478,10 @@ unsigned SystemZTTIImpl::getMinPrefetchStride(unsigned NumMemAccesses,
   return ST->hasMiscellaneousExtensions3() ? 8192 : 2048;
 }
 
+unsigned SystemZTTIImpl::getMaxInterleaveFactor(ElementCount VF) const {
+  return VF.isVector() ? 8 : 1;
+}
+
 bool SystemZTTIImpl::hasDivRemOp(Type *DataType, bool IsSigned) const {
   EVT VT = TLI->getValueType(DL, DataType);
   return (VT.isScalarInteger() && TLI->isTypeLegal(VT));
@@ -1086,6 +1090,16 @@ static unsigned getOperandsExtensionCost(const Instruction *I) {
   return ExtCost;
 }
 
+InstructionCost SystemZTTIImpl::getCFInstrCost(unsigned Opcode,
+                                           TTI::TargetCostKind CostKind,
+                                           const Instruction *I) const {
+  if (CostKind != TTI::TCK_RecipThroughput)
+    return Opcode == Instruction::PHI ? TTI::TCC_Free : TTI::TCC_Basic;
+  assert(CostKind == TTI::TCK_RecipThroughput && "unexpected CostKind");
+  // Branches are assumed to be predicted.
+  return TTI::TCC_Free;
+}
+
 InstructionCost SystemZTTIImpl::getCmpSelInstrCost(
     unsigned Opcode, Type *ValTy, Type *CondTy, CmpInst::Predicate VecPred,
     TTI::TargetCostKind CostKind, TTI::OperandValueInfo Op1Info,
diff --git a/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h b/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
index d96036067c786..333da5ffaa13e 100644
--- a/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
+++ b/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
@@ -82,6 +82,8 @@ class SystemZTTIImpl final : public BasicTTIImplBase<SystemZTTIImpl> {
                                 bool HasCall) const override;
   bool enableWritePrefetching() const override { return true; }
 
+  unsigned getMaxInterleaveFactor(ElementCount VF) const override;
+
   bool hasDivRemOp(Type *DataType, bool IsSigned) const override;
   bool prefersVectorizedAddressing() const override { return false; }
   bool LSRWithInstrQueries() const override { return true; }
@@ -114,6 +116,8 @@ class SystemZTTIImpl final : public BasicTTIImplBase<SystemZTTIImpl> {
   getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src,
                    TTI::CastContextHint CCH, TTI::TargetCostKind CostKind,
                    const Instruction *I = nullptr) const override;
+  InstructionCost getCFInstrCost(unsigned Opcode, TTI::TargetCostKind CostKind,
+                                 const Instruction *I = nullptr) const override;
   InstructionCost getCmpSelInstrCost(
       unsigned Opcode, Type *ValTy, Type *CondTy, CmpInst::Predicate VecPred,
       TTI::TargetCostKind CostKind,

``````````

</details>


https://github.com/llvm/llvm-project/pull/184306