[SLPVectorizer] minor tweaks around lambdas for compatibilty with older compilers

[AlexMaclean]

Older version of msvc do not have great lambda support and are not able to handle uses of class data or lambdas with implicit return types in some cases. These minor changes improve the sources compatibility with older msvc and don't hurt readability either.

[llvmbot]

@llvm/pr-subscribers-vectorizers

@llvm/pr-subscribers-llvm-transforms

Author: Alex MacLean (AlexMaclean)

Changes

Older version of msvc do not have great lambda support and are not able to handle uses of class data or lambdas with implicit return types in some cases. These minor changes improve the sources compatibility with older msvc and don't hurt readability either.

---

Full diff: https://github.com/llvm/llvm-project/pull/122348.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp (+12-10)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 36fed8937aec28..8e361f505419df 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -6923,8 +6923,8 @@ void BoUpSLP::tryToVectorizeGatheredLoads(
                              Loads.size());
     Align Alignment = computeCommonAlignment<LoadInst>(Values);
     auto *Ty = getWidenedType(Loads.front()->getType(), Loads.size());
-    return TTI->isLegalMaskedGather(Ty, Alignment) &&
-           !TTI->forceScalarizeMaskedGather(Ty, Alignment);
+    return this->TTI->isLegalMaskedGather(Ty, Alignment) &&
+           !this->TTI->forceScalarizeMaskedGather(Ty, Alignment);
   };
 
   auto GetVectorizedRanges = [this](ArrayRef<LoadInst *> Loads,
@@ -7085,9 +7085,10 @@ void BoUpSLP::tryToVectorizeGatheredLoads(
           }
           SmallVector<std::pair<LoadInst *, int>> LocalLoadsDists(LoadsDists);
           SmallVector<LoadInst *> OriginalLoads(LocalLoadsDists.size());
-          transform(
-              LoadsDists, OriginalLoads.begin(),
-              [](const std::pair<LoadInst *, int> &L) { return L.first; });
+          transform(LoadsDists, OriginalLoads.begin(),
+                    [](const std::pair<LoadInst *, int> &L) -> LoadInst * {
+                      return L.first;
+                    });
           stable_sort(LocalLoadsDists, LoadSorter);
           SmallVector<LoadInst *> Loads;
           unsigned MaxConsecutiveDistance = 0;
@@ -7314,7 +7315,8 @@ void BoUpSLP::tryToVectorizeGatheredLoads(
     if (!Ref.empty() && !NonVectorized.empty() &&
         std::accumulate(
             Ref.begin(), Ref.end(), 0u,
-            [](unsigned S, ArrayRef<std::pair<LoadInst *, int>> LoadsDists) {
+            [](unsigned S,
+               ArrayRef<std::pair<LoadInst *, int>> LoadsDists) -> unsigned {
               return S + LoadsDists.size();
             }) != NonVectorized.size() &&
         IsMaskedGatherSupported(NonVectorized)) {
@@ -17003,8 +17005,8 @@ void BoUpSLP::optimizeGatherSequence() {
     // Check if the last undefs actually change the final number of used vector
     // registers.
     return SM1.size() - LastUndefsCnt > 1 &&
-           TTI->getNumberOfParts(SI1->getType()) ==
-               TTI->getNumberOfParts(
+           this->TTI->getNumberOfParts(SI1->getType()) ==
+               this->TTI->getNumberOfParts(
                    getWidenedType(SI1->getType()->getElementType(),
                                   SM1.size() - LastUndefsCnt));
   };
@@ -17784,8 +17786,8 @@ bool BoUpSLP::collectValuesToDemote(
       const unsigned VF = E.Scalars.size();
       Type *OrigScalarTy = E.Scalars.front()->getType();
       if (UniqueBases.size() <= 2 ||
-          TTI->getNumberOfParts(getWidenedType(OrigScalarTy, VF)) ==
-              TTI->getNumberOfParts(getWidenedType(
+          this->TTI->getNumberOfParts(getWidenedType(OrigScalarTy, VF)) ==
+              this->TTI->getNumberOfParts(getWidenedType(
                   IntegerType::get(OrigScalarTy->getContext(), BitWidth), VF)))
         ToDemote.push_back(E.Idx);
     }

[alexey-bataev]

I suggest something like this instead:

auto IsMaskedGatherSupported = [&, TTI=TTI](ArrayRef<LoadInst *> Loads) {

[AlexMaclean]

Sounds good, fixed