[llvm] [SLP][REVEC] Make MinBWs support vector instructions. (PR #103049)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Han-Kuan Chen (HanKuanChen)

<details>
<summary>Changes</summary>


If ScalarTy is FixedVectorType, it should remain as FixedVectorType.

---
Full diff: https://github.com/llvm/llvm-project/pull/103049.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp (+19-7) 
- (modified) llvm/test/Transforms/SLPVectorizer/revec.ll (+24) 


``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 8a08d766a8ed4..ebfb11f841086 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -9527,8 +9527,12 @@ BoUpSLP::getEntryCost(const TreeEntry *E, ArrayRef<Value *> VectorizedVals,
   // that the costs will be accurate.
   auto It = MinBWs.find(E);
   Type *OrigScalarTy = ScalarTy;
-  if (It != MinBWs.end())
+  if (It != MinBWs.end()) {
+    auto VecTy = dyn_cast<FixedVectorType>(ScalarTy);
     ScalarTy = IntegerType::get(F->getContext(), It->second.first);
+    if (VecTy)
+      ScalarTy = getWidenedType(ScalarTy, VecTy->getNumElements());
+  }
   auto *VecTy = getWidenedType(ScalarTy, VL.size());
   unsigned EntryVF = E->getVectorFactor();
   auto *FinalVecTy = getWidenedType(ScalarTy, EntryVF);
@@ -13127,8 +13131,12 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E, bool PostponedPHIs) {
   else if (auto *IE = dyn_cast<InsertElementInst>(V))
     ScalarTy = IE->getOperand(1)->getType();
   auto It = MinBWs.find(E);
-  if (It != MinBWs.end())
+  if (It != MinBWs.end()) {
+    auto VecTy = dyn_cast<FixedVectorType>(ScalarTy);
     ScalarTy = IntegerType::get(F->getContext(), It->second.first);
+    if (VecTy)
+      ScalarTy = getWidenedType(ScalarTy, VecTy->getNumElements());
+  }
   auto *VecTy = getWidenedType(ScalarTy, E->Scalars.size());
   if (E->isGather()) {
     // Set insert point for non-reduction initial nodes.
@@ -16003,8 +16011,9 @@ void BoUpSLP::computeMinimumValueSizes() {
     }
 
     unsigned VF = E.getVectorFactor();
-    auto *TreeRootIT =
-        dyn_cast<IntegerType>(E.Scalars.front()->getType()->getScalarType());
+    Type *ScalarTy = E.Scalars.front()->getType();
+    unsigned ScalarTyNumElements = getNumElements(ScalarTy);
+    auto *TreeRootIT = dyn_cast<IntegerType>(ScalarTy->getScalarType());
     if (!TreeRootIT || !Opcode)
       return 0u;
 
@@ -16012,7 +16021,8 @@ void BoUpSLP::computeMinimumValueSizes() {
                [&](Value *V) { return AnalyzedMinBWVals.contains(V); }))
       return 0u;
 
-    unsigned NumParts = TTI->getNumberOfParts(getWidenedType(TreeRootIT, VF));
+    unsigned NumParts = TTI->getNumberOfParts(
+        getWidenedType(TreeRootIT, VF * ScalarTyNumElements));
 
     // The maximum bit width required to represent all the values that can be
     // demoted without loss of precision. It would be safe to truncate the roots
@@ -16034,7 +16044,8 @@ void BoUpSLP::computeMinimumValueSizes() {
     // we can truncate the roots to this narrower type.
     for (Value *Root : E.Scalars) {
       unsigned NumSignBits = ComputeNumSignBits(Root, *DL, 0, AC, nullptr, DT);
-      TypeSize NumTypeBits = DL->getTypeSizeInBits(Root->getType());
+      TypeSize NumTypeBits =
+          DL->getTypeSizeInBits(Root->getType()->getScalarType());
       unsigned BitWidth1 = NumTypeBits - NumSignBits;
       // If we can't prove that the sign bit is zero, we must add one to the
       // maximum bit width to account for the unknown sign bit. This preserves
@@ -16206,7 +16217,8 @@ void BoUpSLP::computeMinimumValueSizes() {
     // type, we can proceed with the narrowing. Otherwise, do nothing.
     if (MaxBitWidth == 0 ||
         MaxBitWidth >=
-            cast<IntegerType>(TreeRoot.front()->getType())->getBitWidth()) {
+            cast<IntegerType>(TreeRoot.front()->getType()->getScalarType())
+                ->getBitWidth()) {
       if (UserIgnoreList)
         AnalyzedMinBWVals.insert(TreeRoot.begin(), TreeRoot.end());
       continue;
diff --git a/llvm/test/Transforms/SLPVectorizer/revec.ll b/llvm/test/Transforms/SLPVectorizer/revec.ll
index 9ce9db1d360cc..31ee107c81cd4 100644
--- a/llvm/test/Transforms/SLPVectorizer/revec.ll
+++ b/llvm/test/Transforms/SLPVectorizer/revec.ll
@@ -272,3 +272,27 @@ for.body:
   %5 = phi <2 x float> [ %5, %for.body ], [ zeroinitializer, %entry ]
   br i1 false, label %for0, label %for.body
 }
+
+define void @test9() {
+; CHECK-LABEL: @test9(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = call <8 x i16> @llvm.vector.insert.v8i16.v4i16(<8 x i16> poison, <4 x i16> zeroinitializer, i64 0)
+; CHECK-NEXT:    [[TMP1:%.*]] = call <8 x i16> @llvm.vector.insert.v8i16.v4i16(<8 x i16> [[TMP0]], <4 x i16> zeroinitializer, i64 4)
+; CHECK-NEXT:    br label [[FOR_BODY13:%.*]]
+; CHECK:       for.body13:
+; CHECK-NEXT:    [[TMP2:%.*]] = trunc <8 x i16> [[TMP1]] to <8 x i1>
+; CHECK-NEXT:    [[TMP3:%.*]] = zext <8 x i1> [[TMP2]] to <8 x i32>
+; CHECK-NEXT:    store <8 x i32> [[TMP3]], ptr null, align 4
+; CHECK-NEXT:    br label [[FOR_BODY13]]
+;
+entry:
+  br label %for.body13
+
+for.body13:                                       ; preds = %for.body13, %entry
+  %vmovl.i111 = sext <4 x i16> zeroinitializer to <4 x i32>
+  %vmovl.i110 = sext <4 x i16> zeroinitializer to <4 x i32>
+  store <4 x i32> %vmovl.i111, ptr null, align 4
+  %add.ptr29 = getelementptr i8, ptr null, i64 16
+  store <4 x i32> %vmovl.i110, ptr %add.ptr29, align 4
+  br label %for.body13
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/103049