[SVE] Fix bug in DataLayout::getIndexType

[david-arm]

Summary

We were previously assuming all vectors of indices were fixed
length, which is not true. I've added a new test that exposes
this code path.

[david-arm]

Looks like it has already been fixed by commit https://reviews.llvm.org/D82061

llvm/lib/IR/DataLayout.cpp

 }
 
 Type *DataLayout::getIndexType(Type *Ty) const {
   assert(Ty->isPtrOrPtrVectorTy() &&
          "Expected a pointer or pointer vector type.");
   unsigned NumBits = getIndexTypeSizeInBits(Ty);
   IntegerType *IntTy = IntegerType::get(Ty->getContext(), NumBits);
   if (VectorType *VecTy = dyn_cast<VectorType>(Ty))
-    return FixedVectorType::get(IntTy, VecTy->getNumElements());
+    return VectorType::get(IntTy, VecTy);
   return IntTy;
 }
 
 int64_t DataLayout::getIndexedOffsetInType(Type *ElemTy,
                                            ArrayRef<Value *> Indices) const {
   int64_t Result = 0;
 
   generic_gep_type_iterator<Value* const*>

llvm/test/Transforms/InstCombine/gep-vector.ll

;
   %asc = addrspacecast [4 x i32]* %arr_ptr to [4 x i32] addrspace(3)*
   %gep = getelementptr inbounds [4 x i32], [4 x i32] addrspace(3)* %asc, i64 %y, i64 %z
   ret i32 addrspace(3)* %gep
 }
 
 ; Negative test - avoid doing bitcast on i8*, because '16' should be scaled by 'vscale'.
 
 define i8* @test_accumulate_constant_offset_vscale_nonzero(<vscale x 16 x i1> %pg, i8* %base) {
-; CHECK-LABEL: @test_accumulate_constant_offset_vscale_nonzero
-; CHECK-NEXT:   %bc = bitcast i8* %base to <vscale x 16 x i8>*
-; CHECK-NEXT:   %gep = getelementptr <vscale x 16 x i8>, <vscale x 16 x i8>* %bc, i64 1, i64 4
-; CHECK-NEXT:   ret i8* %gep
+; CHECK-LABEL: @test_accumulate_constant_offset_vscale_nonzero(
+; CHECK-NEXT:    [[BC:%.*]] = bitcast i8* [[BASE:%.*]] to <vscale x 16 x i8>*
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr <vscale x 16 x i8>, <vscale x 16 x i8>* [[BC]], i64 1, i64 4
+; CHECK-NEXT:    ret i8* [[GEP]]
+;
   %bc = bitcast i8* %base to <vscale x 16 x i8>*
   %gep = getelementptr <vscale x 16 x i8>, <vscale x 16 x i8>* %bc, i64 1, i64 4
   ret i8* %gep
 }
 
 define i8* @test_accumulate_constant_offset_vscale_zero(<vscale x 16 x i1> %pg, i8* %base) {
-; CHECK-LABEL: @test_accumulate_constant_offset_vscale_zero
-; CHECK-NEXT:   %[[RES:.*]] = getelementptr i8, i8* %base, i64 4
-; CHECK-NEXT:   ret i8* %[[RES]]
+; CHECK-LABEL: @test_accumulate_constant_offset_vscale_zero(
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr i8, i8* [[BASE:%.*]], i64 4
+; CHECK-NEXT:    ret i8* [[TMP1]]
+;
   %bc = bitcast i8* %base to <vscale x 16 x i8>*
   %gep = getelementptr <vscale x 16 x i8>, <vscale x 16 x i8>* %bc, i64 0, i64 4
   ret i8* %gep
 }
+
+@GLOBAL = internal global i32 zeroinitializer
+
+define i32* @gep_cvbase_w_cv_idx(<vscale x 2 x i32*> %base, i64 %raw_addr) {
+; CHECK-LABEL: @gep_cvbase_w_cv_idx(
+; CHECK-NEXT:    ret i32* extractelement (<vscale x 2 x i32*> shufflevector (<vscale x 2 x i32*> insertelement (<vscale x 2 x i32*> undef, i32* @GLOBAL, i32 0), <vscale x 2 x i32*> undef, <vscale x 2 x i32> zeroinitializer), i32 0)
+;
+  %ins1 = insertelement <vscale x 2 x i32*> undef, i32* @GLOBAL, i32 0
+  %splat1 = shufflevector <vscale x 2 x i32*> %ins1, <vscale x 2 x i32*> undef, <vscale x 2 x i32> zeroinitializer
+  %gep = getelementptr i32, <vscale x 2 x i32*> %splat1, <vscale x 2 x i64> zeroinitializer
+  %ee = extractelement <vscale x 2 x i32*> %gep, i32 0
+  ret i32* %ee
+}
+