[SLP]Fix PR107036: Check if the type of the user is sizable before requesting its size.

Only some instructions should be considered as potentially reducing the
size of the operands types, not all instructions should be considered.

Fixes #107036

Author: alexey-bataev

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -16055,15 +16055,16 @@ void BoUpSLP::computeMinimumValueSizes() {
                     const TreeEntry *UserTE = E.UserTreeIndices.back().UserTE;
                     if (TE == UserTE || !TE)
                       return false;
+                    if (!isa<CastInst, BinaryOperator, FreezeInst, PHINode,
+                             SelectInst>(U) ||
+                        !isa<CastInst, BinaryOperator, FreezeInst, PHINode,
+                             SelectInst>(UserTE->getMainOp()))
+                      return true;
                     unsigned UserTESz = DL->getTypeSizeInBits(
                         UserTE->Scalars.front()->getType());
                     auto It = MinBWs.find(TE);
                     if (It != MinBWs.end() && It->second.first > UserTESz)
                       return true;
-                    // The size of icmp is always 1 and should not be
-                    // considered.
-                    if (TE->getOpcode() == Instruction::ICmp)
-                      return true;
                     return DL->getTypeSizeInBits(U->getType()) > UserTESz;
                   }));
         })) {

llvm/test/Transforms/SLPVectorizer/X86/minbw-user-non-sizable.ll

@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S --passes=slp-vectorizer -mtriple=x86_64-unknown-linux-gnu < %s -slp-threshold=-100 | FileCheck %s
+
+define void @test(ptr %i) {
+; CHECK-LABEL: define void @test(
+; CHECK-SAME: ptr [[I:%.*]]) {
+; CHECK-NEXT:  [[BB:.*]]:
+; CHECK-NEXT:    br label %[[BB2:.*]]
+; CHECK:       [[BB2]]:
+; CHECK-NEXT:    [[TMP0:%.*]] = phi <2 x i32> [ [[TMP3:%.*]], %[[BB2]] ], [ zeroinitializer, %[[BB]] ]
+; CHECK-NEXT:    store <2 x i32> [[TMP0]], ptr [[I]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <2 x i32> [[TMP0]], <2 x i32> <i32 0, i32 poison>, <2 x i32> <i32 2, i32 1>
+; CHECK-NEXT:    [[TMP2:%.*]] = trunc <2 x i32> [[TMP1]] to <2 x i1>
+; CHECK-NEXT:    [[TMP3]] = select <2 x i1> [[TMP2]], <2 x i32> zeroinitializer, <2 x i32> zeroinitializer
+; CHECK-NEXT:    br label %[[BB2]]
+;
+bb:
+  %i1 = getelementptr i8, ptr %i, i64 4
+  br label %bb2
+
+bb2:
+  %i3 = phi i32 [ %i6, %bb2 ], [ 0, %bb ]
+  %i4 = phi i32 [ %i8, %bb2 ], [ 0, %bb ]
+  store i32 %i3, ptr %i
+  store i32 %i4, ptr %i1
+  %i5 = trunc i32 0 to i1
+  %i6 = select i1 %i5, i32 0, i32 0
+  %i7 = trunc i32 %i4 to i1
+  %i8 = select i1 %i7, i32 0, i32 0
+  br label %bb2
+}