[llvm] [SLP][REVEC] Use VL.front()->getType() as ScalarTy. (PR #102437)

[Han-Kuan Chen via llvm-commits]

https://github.com/HanKuanChen created https://github.com/llvm/llvm-project/pull/102437

None

>From 6d1b00fbcfdece24db8659fad41810d97ee067b3 Mon Sep 17 00:00:00 2001
From: Han-Kuan Chen <hankuan.chen at sifive.com>
Date: Thu, 25 Jul 2024 17:22:19 -0700
Subject: [PATCH 1/2] [SLP][REVEC] Pre-commit test.

---
 llvm/test/Transforms/SLPVectorizer/revec.ll | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/llvm/test/Transforms/SLPVectorizer/revec.ll b/llvm/test/Transforms/SLPVectorizer/revec.ll
index d6dd4128de9c7e..b8d374d3d0a889 100644
--- a/llvm/test/Transforms/SLPVectorizer/revec.ll
+++ b/llvm/test/Transforms/SLPVectorizer/revec.ll
@@ -124,3 +124,20 @@ entry:
   store <8 x i1> %6, ptr %7, align 1
   ret void
 }
+
+define void @test5() {
+entry:
+  br i1 false, label %for.cond.cleanup.loopexit.unr-lcssa, label %for.body
+
+for.cond.cleanup.loopexit.unr-lcssa:              ; preds = %for.body, %entry
+  %0 = phi <2 x float> [ zeroinitializer, %entry ], [ %4, %for.body ]
+  %1 = phi <2 x float> [ zeroinitializer, %entry ], [ %5, %for.body ]
+  %2 = phi <2 x float> [ zeroinitializer, %entry ], [ %4, %for.body ]
+  %3 = phi <2 x float> [ zeroinitializer, %entry ], [ %5, %for.body ]
+  ret void
+
+for.body:                                         ; preds = %for.body, %entry
+  %4 = phi <2 x float> [ %4, %for.body ], [ zeroinitializer, %entry ]
+  %5 = phi <2 x float> [ %5, %for.body ], [ zeroinitializer, %entry ]
+  br i1 false, label %for.cond.cleanup.loopexit.unr-lcssa, label %for.body
+}

>From eed2f9c6e3cd07ec84741aee2cdd013f3724fefd Mon Sep 17 00:00:00 2001
From: Han-Kuan Chen <hankuan.chen at sifive.com>
Date: Thu, 4 Jul 2024 22:25:52 -0700
Subject: [PATCH 2/2] [SLP][REVEC] Use VL.front()->getType() as ScalarTy.

VL.front()->getType() may be FixedVectorType when revec is enabled.

Fix "Expected item in MinBWs.".
---
 llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp |  4 ++--
 llvm/test/Transforms/SLPVectorizer/revec.ll     | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 7619e744f7a2f7..1956e7f9618372 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -12391,8 +12391,8 @@ Value *BoUpSLP::vectorizeOperand(TreeEntry *E, unsigned NodeIdx,
     }
     if (IsSameVE) {
       auto FinalShuffle = [&](Value *V, ArrayRef<int> Mask) {
-        ShuffleInstructionBuilder ShuffleBuilder(
-            cast<VectorType>(V->getType())->getElementType(), Builder, *this);
+        ShuffleInstructionBuilder ShuffleBuilder(VL.front()->getType(), Builder,
+                                                 *this);
         ShuffleBuilder.add(V, Mask);
         return ShuffleBuilder.finalize(std::nullopt);
       };
diff --git a/llvm/test/Transforms/SLPVectorizer/revec.ll b/llvm/test/Transforms/SLPVectorizer/revec.ll
index b8d374d3d0a889..f457042d931146 100644
--- a/llvm/test/Transforms/SLPVectorizer/revec.ll
+++ b/llvm/test/Transforms/SLPVectorizer/revec.ll
@@ -126,6 +126,23 @@ entry:
 }
 
 define void @test5() {
+; CHECK-LABEL: @test5(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = call <8 x float> @llvm.vector.insert.v8f32.v2f32(<8 x float> poison, <2 x float> zeroinitializer, i64 0)
+; CHECK-NEXT:    [[TMP1:%.*]] = call <8 x float> @llvm.vector.insert.v8f32.v2f32(<8 x float> [[TMP0]], <2 x float> zeroinitializer, i64 2)
+; CHECK-NEXT:    [[TMP2:%.*]] = call <8 x float> @llvm.vector.insert.v8f32.v2f32(<8 x float> [[TMP1]], <2 x float> zeroinitializer, i64 4)
+; CHECK-NEXT:    [[TMP3:%.*]] = call <8 x float> @llvm.vector.insert.v8f32.v2f32(<8 x float> [[TMP2]], <2 x float> zeroinitializer, i64 6)
+; CHECK-NEXT:    [[TMP4:%.*]] = call <4 x float> @llvm.vector.insert.v4f32.v2f32(<4 x float> poison, <2 x float> zeroinitializer, i64 0)
+; CHECK-NEXT:    [[TMP5:%.*]] = call <4 x float> @llvm.vector.insert.v4f32.v2f32(<4 x float> [[TMP4]], <2 x float> zeroinitializer, i64 2)
+; CHECK-NEXT:    br i1 false, label [[FOR_COND_CLEANUP_LOOPEXIT_UNR_LCSSA:%.*]], label [[FOR_BODY:%.*]]
+; CHECK:       for.cond.cleanup.loopexit.unr-lcssa:
+; CHECK-NEXT:    [[TMP6:%.*]] = phi <8 x float> [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TMP8:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT:    ret void
+; CHECK:       for.body:
+; CHECK-NEXT:    [[TMP7:%.*]] = phi <4 x float> [ [[TMP7]], [[FOR_BODY]] ], [ [[TMP5]], [[ENTRY]] ]
+; CHECK-NEXT:    [[TMP8]] = shufflevector <4 x float> [[TMP7]], <4 x float> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    br i1 false, label [[FOR_COND_CLEANUP_LOOPEXIT_UNR_LCSSA]], label [[FOR_BODY]]
+;
 entry:
   br i1 false, label %for.cond.cleanup.loopexit.unr-lcssa, label %for.body