[llvm] [SLP][REVEC] Fix CompressVectorize does not expand mask when REVEC is enabled. (PR #135174)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-vectorizers

Author: Han-Kuan Chen (HanKuanChen)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/135174.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp (+15) 
- (added) llvm/test/Transforms/SLPVectorizer/X86/revec-load-compress.ll (+34) 


``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 4611d162edbe2..731d6d58efbce 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -17610,6 +17610,18 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
               ConstantInt::getFalse(VecTy->getContext()));
           for (int I : CompressMask)
             MaskValues[I] = ConstantInt::getTrue(VecTy->getContext());
+          if (auto *VecTy = dyn_cast<FixedVectorType>(LI->getType())) {
+            assert(SLPReVec && "Only supported by REVEC.");
+            unsigned VecTyNumElements = VecTy->getNumElements();
+            SmallVector<Constant *> NewMaskValues(
+                MaskValues.size() * VecTyNumElements,
+                ConstantInt::getFalse(VecTy->getContext()));
+            for (auto [I, V] : enumerate(MaskValues))
+              if (V->isOneValue())
+                std::fill_n(NewMaskValues.begin() + I * VecTyNumElements,
+                            VecTyNumElements, V);
+            MaskValues.swap(NewMaskValues);
+          }
           Constant *MaskValue = ConstantVector::get(MaskValues);
           NewLI = Builder.CreateMaskedLoad(LoadVecTy, PO, CommonAlignment,
                                            MaskValue);
@@ -17618,6 +17630,9 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
         }
         NewLI = ::propagateMetadata(NewLI, E->Scalars);
         // TODO: include this cost into CommonCost.
+        if (auto *VecTy = dyn_cast<FixedVectorType>(LI->getType()))
+          transformScalarShuffleIndiciesToVector(VecTy->getNumElements(),
+                                                 CompressMask);
         NewLI =
             cast<Instruction>(Builder.CreateShuffleVector(NewLI, CompressMask));
       } else if (E->State == TreeEntry::StridedVectorize) {
diff --git a/llvm/test/Transforms/SLPVectorizer/X86/revec-load-compress.ll b/llvm/test/Transforms/SLPVectorizer/X86/revec-load-compress.ll
new file mode 100644
index 0000000000000..069274df396d7
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/X86/revec-load-compress.ll
@@ -0,0 +1,34 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -mtriple=x86_64-unknown-linux-gnu -mattr=+avx10.1-512 -passes=slp-vectorizer -S -slp-revec < %s | FileCheck %s
+
+define void @test(ptr %in) {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i8, ptr [[IN:%.*]], i64 32
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr i8, ptr [[IN]], i64 64
+; CHECK-NEXT:    [[TMP2:%.*]] = call <32 x i16> @llvm.masked.load.v32i16.p0(ptr [[TMP1]], i32 2, <32 x i1> <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>, <32 x i16> poison)
+; CHECK-NEXT:    [[TMP3:%.*]] = shufflevector <32 x i16> [[TMP2]], <32 x i16> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; CHECK-NEXT:    [[TMP4:%.*]] = call <16 x i32> @llvm.vector.insert.v16i32.v8i32(<16 x i32> poison, <8 x i32> zeroinitializer, i64 0)
+; CHECK-NEXT:    [[TMP5:%.*]] = call <16 x i32> @llvm.vector.insert.v16i32.v8i32(<16 x i32> [[TMP4]], <8 x i32> zeroinitializer, i64 8)
+; CHECK-NEXT:    [[TMP6:%.*]] = trunc <16 x i32> [[TMP5]] to <16 x i16>
+; CHECK-NEXT:    [[TMP7:%.*]] = or <16 x i16> [[TMP6]], [[TMP3]]
+; CHECK-NEXT:    store <16 x i16> [[TMP7]], ptr [[TMP0]], align 2
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = getelementptr i8, ptr %in, i64 112
+  %wide.load = load <8 x i16>, ptr %0, align 2
+  %1 = sext <8 x i16> %wide.load to <8 x i32>
+  %2 = getelementptr i8, ptr %in, i64 48
+  %3 = or <8 x i32> zeroinitializer, %1
+  %4 = getelementptr i8, ptr %in, i64 32
+  %5 = getelementptr i8, ptr %in, i64 64
+  %wide.load155 = load <8 x i16>, ptr %5, align 2
+  %6 = sext <8 x i16> %wide.load155 to <8 x i32>
+  %7 = or <8 x i32> zeroinitializer, %6
+  %8 = trunc <8 x i32> %3 to <8 x i16>
+  store <8 x i16> %8, ptr %2, align 2
+  %9 = trunc <8 x i32> %7 to <8 x i16>
+  store <8 x i16> %9, ptr %4, align 2
+  ret void
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/135174