[SLP]Consider unsigned nodes, feeding into sitofp, being converted using

uitofp.

Need to use uitofp for unsigned nodes, which are part of minbitwidth
analysis, to correctly handle signedness info.

Author: alexey-bataev

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -9020,6 +9020,9 @@ BoUpSLP::getEntryCost(const TreeEntry *E, ArrayRef<Value *> VectorizedVals,
         VecOpcode =
             SrcIt->second.second ? Instruction::SExt : Instruction::ZExt;
       }
+    } else if (VecOpcode == Instruction::SIToFP && SrcIt != MinBWs.end() &&
+               !SrcIt->second.second) {
+      VecOpcode = Instruction::UIToFP;
     }
     auto GetScalarCost = [&](unsigned Idx) -> InstructionCost {
       auto *VI = cast<Instruction>(UniqueValues[Idx]);
@@ -12398,6 +12401,9 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E, bool PostponedPHIs) {
           VecOpcode =
               SrcIt->second.second ? Instruction::SExt : Instruction::ZExt;
         }
+      } else if (VecOpcode == Instruction::SIToFP && SrcIt != MinBWs.end() &&
+                 !SrcIt->second.second) {
+        VecOpcode = Instruction::UIToFP;
       }
       Value *V = (VecOpcode != ShuffleOrOp && VecOpcode == Instruction::BitCast)
                      ? InVec

llvm/test/Transforms/SLPVectorizer/X86/sitofp-minbitwidth-node.ll

@@ -8,7 +8,7 @@ define void @foo(ptr %ptr) {
 ; CHECK-NEXT:    [[GEP3:%.*]] = getelementptr inbounds i8, ptr [[PTR]], i64 334
 ; CHECK-NEXT:    [[TMP1:%.*]] = load <2 x i16>, ptr [[GEP0]], align 8
 ; CHECK-NEXT:    [[TMP3:%.*]] = xor <2 x i16> [[TMP1]], <i16 -1, i16 -1>
-; CHECK-NEXT:    [[TMP4:%.*]] = sitofp <2 x i16> [[TMP3]] to <2 x double>
+; CHECK-NEXT:    [[TMP4:%.*]] = uitofp <2 x i16> [[TMP3]] to <2 x double>
 ; CHECK-NEXT:    [[TMP5:%.*]] = load <2 x i16>, ptr [[GEP3]], align 2
 ; CHECK-NEXT:    [[TMP6:%.*]] = zext <2 x i16> [[TMP5]] to <2 x i32>
 ; CHECK-NEXT:    [[TMP2:%.*]] = zext <2 x i16> [[TMP1]] to <2 x i32>