[COST]Fix PR35865: Fix cost model evaluation for shuffle on X86.

[ABataev]

Summary

If the vector type is transformed to non-vector single type, the compile
may crash trying to get vector information about non-vector type.

[RKSimon]

LGTM with one minor

test/Transforms/SLPVectorizer/X86/crash_shuffle.ll

2 ↗

(On Diff #129077)

Rename this pr35865.ll ? Its useful not to have to goto svn log to find where a test came from (and crash_shuffle.ll isn't that useful a name....).

llvm/trunk/lib/Target/X86/X86TargetTransformInfo.cpp

int X86TTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
   if (Kind == TTI::SK_Broadcast)
     LT.first = 1;
 
   // We are going to permute multiple sources and the result will be in multiple
   // destinations. Providing an accurate cost only for splits where the element
   // type remains the same.
   if (Kind == TTI::SK_PermuteSingleSrc && LT.first != 1) {
     MVT LegalVT = LT.second;
-    if (LegalVT.getVectorElementType().getSizeInBits() ==
+    if (LegalVT.isVector() &&
+        LegalVT.getVectorElementType().getSizeInBits() ==
             Tp->getVectorElementType()->getPrimitiveSizeInBits() &&
         LegalVT.getVectorNumElements() < Tp->getVectorNumElements()) {
 
       unsigned VecTySize = DL.getTypeStoreSize(Tp);
       unsigned LegalVTSize = LegalVT.getStoreSize();
       // Number of source vectors after legalization:
       unsigned NumOfSrcs = (VecTySize + LegalVTSize - 1) / LegalVTSize;
       // Number of destination vectors after legalization:

llvm/trunk/test/Transforms/SLPVectorizer/X86/PR35865.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -slp-vectorizer < %s -S -o - -mtriple=x86_64-apple-macosx10.10.0 -mcpu=core2 | FileCheck %s
+
+define void @_Z10fooConvertPDv4_xS0_S0_PKS_() {
+; CHECK-LABEL: @_Z10fooConvertPDv4_xS0_S0_PKS_(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <16 x half> undef, i32 4
+; CHECK-NEXT:    [[CONV_I_4_I:%.*]] = fpext half [[TMP0]] to float
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast float [[CONV_I_4_I]] to i32
+; CHECK-NEXT:    [[VECINS_I_4_I:%.*]] = insertelement <8 x i32> undef, i32 [[TMP1]], i32 4
+; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <16 x half> undef, i32 5
+; CHECK-NEXT:    [[CONV_I_5_I:%.*]] = fpext half [[TMP2]] to float
+; CHECK-NEXT:    [[TMP3:%.*]] = bitcast float [[CONV_I_5_I]] to i32
+; CHECK-NEXT:    [[VECINS_I_5_I:%.*]] = insertelement <8 x i32> [[VECINS_I_4_I]], i32 [[TMP3]], i32 5
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = extractelement <16 x half> undef, i32 4
+  %conv.i.4.i = fpext half %0 to float
+  %1 = bitcast float %conv.i.4.i to i32
+  %vecins.i.4.i = insertelement <8 x i32> undef, i32 %1, i32 4
+  %2 = extractelement <16 x half> undef, i32 5
+  %conv.i.5.i = fpext half %2 to float
+  %3 = bitcast float %conv.i.5.i to i32
+  %vecins.i.5.i = insertelement <8 x i32> %vecins.i.4.i, i32 %3, i32 5
+  ret void
+}