[CodeGenPrepare][AArch64] Fix a TLI legality check on iPTR to use a lowered instead.

Fixes PR21548.  Related to PR20474.

llvm-svn: 221820
diff --git a/llvm/test/Transforms/CodeGenPrepare/AArch64/trunc-weird-user.ll b/llvm/test/Transforms/CodeGenPrepare/AArch64/trunc-weird-user.ll
index 1a08780..b4e6a40 100644
--- a/llvm/test/Transforms/CodeGenPrepare/AArch64/trunc-weird-user.ll
+++ b/llvm/test/Transforms/CodeGenPrepare/AArch64/trunc-weird-user.ll
@@ -15,3 +15,22 @@
   %struct = insertvalue %foo undef, i8 %byte, 0
   ret %"foo" %struct
 }
+
+define i64* @test_merge_PR21548(i32 %a, i64* %p1, i64* %p2, i64* %p3) {
+; CHECK-LABEL: @test_merge_PR21548
+  %as = lshr i32 %a, 3
+  %Tr = trunc i32 %as to i1
+  br i1 %Tr, label %BB2, label %BB3
+
+BB2:
+  ; Similarly to above:
+  ; CodeGenPrepare was requesting the EVT for i8* to determine
+  ; whether the select user of the trunc was legal. This asserted.
+
+; CHECK: select i1 {{%.*}}, i64* %p1, i64* %p2
+  %p = select i1 %Tr, i64* %p1, i64* %p2
+  ret i64* %p
+
+BB3:
+  ret i64* %p3
+}