[slp]

Author: mtrofin

llvm/include/llvm/IR/IRBuilder.h

@@ -2548,6 +2548,11 @@ class IRBuilderBase {
       std::optional<RoundingMode> Rounding = std::nullopt,
       std::optional<fp::ExceptionBehavior> Except = std::nullopt);
 
+  LLVM_ABI Value *CreateSelectWithUnknownProfile(Value *C, Value *True,
+                                                 Value *False,
+                                                 StringRef PassName,
+                                                 const Twine &Name = "");
+
   LLVM_ABI Value *CreateSelect(Value *C, Value *True, Value *False,
                                const Twine &Name = "",
                                Instruction *MDFrom = nullptr);

llvm/lib/IR/IRBuilder.cpp

@@ -25,6 +25,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/NoFolder.h"
 #include "llvm/IR/Operator.h"
+#include "llvm/IR/ProfDataUtils.h"
 #include "llvm/IR/Statepoint.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
@@ -1002,6 +1003,18 @@ CallInst *IRBuilderBase::CreateConstrainedFPCall(
   return C;
 }
 
+Value *IRBuilderBase::CreateSelectWithUnknownProfile(Value *C, Value *True,
+                                                     Value *False,
+                                                     StringRef PassName,
+                                                     const Twine &Name) {
+  Value *Ret = CreateSelectFMF(C, True, False, {}, Name);
+  if (auto *SI = dyn_cast<SelectInst>(Ret)) {
+    setExplicitlyUnknownBranchWeightsIfProfiled(
+        *SI, *SI->getParent()->getParent(), PassName);
+    }
+  return Ret;
+}
+
 Value *IRBuilderBase::CreateSelect(Value *C, Value *True, Value *False,
                                    const Twine &Name, Instruction *MDFrom) {
   return CreateSelectFMF(C, True, False, {}, Name, MDFrom);

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -19414,7 +19414,8 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       }
       assert(getNumElements(Cond->getType()) == TrueNumElements &&
              "Cannot vectorize Instruction::Select");
-      Value *V = Builder.CreateSelect(Cond, True, False);
+      Value *V =
+          Builder.CreateSelectWithUnknownProfile(Cond, True, False, DEBUG_TYPE);
       V = FinalShuffle(V, E);
 
       E->VectorizedValue = V;
@@ -23532,18 +23533,19 @@ class HorizontalReduction {
     switch (Kind) {
     case RecurKind::Or: {
       if (UseSelect && OpTy == CmpInst::makeCmpResultType(OpTy))
-        return Builder.CreateSelect(
+        return Builder.CreateSelectWithUnknownProfile(
             LHS, ConstantInt::getAllOnesValue(CmpInst::makeCmpResultType(OpTy)),
-            RHS, Name);
+            RHS, DEBUG_TYPE, Name);
       unsigned RdxOpcode = RecurrenceDescriptor::getOpcode(Kind);
       return Builder.CreateBinOp((Instruction::BinaryOps)RdxOpcode, LHS, RHS,
                                  Name);
     }
     case RecurKind::And: {
       if (UseSelect && OpTy == CmpInst::makeCmpResultType(OpTy))
-        return Builder.CreateSelect(
+        return Builder.CreateSelectWithUnknownProfile(
             LHS, RHS,
-            ConstantInt::getNullValue(CmpInst::makeCmpResultType(OpTy)), Name);
+            ConstantInt::getNullValue(CmpInst::makeCmpResultType(OpTy)),
+            DEBUG_TYPE, Name);
       unsigned RdxOpcode = RecurrenceDescriptor::getOpcode(Kind);
       return Builder.CreateBinOp((Instruction::BinaryOps)RdxOpcode, LHS, RHS,
                                  Name);
@@ -23564,7 +23566,8 @@ class HorizontalReduction {
       if (UseSelect) {
         CmpInst::Predicate Pred = llvm::getMinMaxReductionPredicate(Kind);
         Value *Cmp = Builder.CreateICmp(Pred, LHS, RHS, Name);
-        return Builder.CreateSelect(Cmp, LHS, RHS, Name);
+        return Builder.CreateSelectWithUnknownProfile(Cmp, LHS, RHS, DEBUG_TYPE,
+                                                      Name);
       }
       [[fallthrough]];
     case RecurKind::FMax: