[RLE-DSE] Add more LIT tests.

Author: trentxintong

test/SILPasses/redundantloadelimination.sil

@@ -87,13 +87,22 @@ enum XYZ {
   case C(Int32)
 }
 
+struct TwoField {
+  var a: Int
+  var b: Int
+  init(a: Int, b: Int)
+  init()
+}
+
 
 sil @use : $@convention(thin) (Builtin.Int32) -> ()
 sil @use_64 : $@convention(thin) (Builtin.Int64) -> ()
 sil @use_2_64 : $@convention(thin) (Builtin.Int64, Builtin.Int64) -> ()
 sil @use_a : $@convention(thin) (A) -> ()
+sil @use_twofield : $@convention(thin) (TwoField) -> ()
 sil @escaped_a_ptr : $@convention(thin) (@out A) -> ()
 sil @escaped_a : $@convention(thin) () -> Builtin.RawPointer
+sil @init_twofield : $@convention(thin) (@thin TwoField.Type) -> TwoField
 
 // DISABLE this test for now. it seems DCE is not getting rid of the load in bb8 after the RLE happens.
 //
@@ -631,4 +640,66 @@ bb2:
   return %9999 : $()
 }
 
+// CHECK-LABEL: store_and_load_to_load_branches_diamond
+// CHECK: bb3
+// CHECK-NOT: load
+// CHECK: return
+sil @store_and_load_to_load_branches_diamond : $@convention(thin) (@inout Builtin.Int32) -> () {
+// %0                                             // users: %1, %4, %9, %11, %16, %21 
+bb0(%0 : $*Builtin.Int32):
+  cond_br undef, bb1, bb2                         // id: %3
 
+bb1:                                              // Preds: bb0 
+  %1 = load %0 : $*Builtin.Int32                  // user: %2
+  br bb3                                          // id: %15 
+
+bb2:                                              // Preds: bb0 
+  %5 = integer_literal $Builtin.Int32, 2
+  store %5 to %0 : $*Builtin.Int32
+  br bb3                                          // id: %20 
+
+bb3:                                              // Preds: bb1 bb2 
+  %21 = load %0 : $*Builtin.Int32                 // user: %23 
+  // function_ref use 
+  %22 = function_ref @use : $@convention(thin) (Builtin.Int32) -> () // user: %23 
+  %23 = apply %22(%21) : $@convention(thin) (Builtin.Int32) -> ()
+  %24 = tuple ()                                  // user: %25 
+  return %24 : $()                                // id: %25 
+}
+
+// CHECK-LABEL: agg_and_field_store_branches_diamond
+// CHECK: bb3
+// CHECK-NOT: load
+// CHECK: return
+sil hidden @agg_and_field_store_branches_diamond : $@convention(thin) (Bool) -> () {
+bb0(%0 : $Bool):
+  %1 = alloc_stack $TwoField  // var x            // users: %6, %11, %16, %21, %24
+  %7 = struct_extract %0 : $Bool, #Bool.value     // user: %8
+  cond_br %7, bb1, bb2                            // id: %8
+
+bb1:                                              // Preds: bb0
+  %9 = integer_literal $Builtin.Int64, 10         // user: %10
+  %10 = struct $Int (%9 : $Builtin.Int64)         // user: %12
+  %11 = struct_element_addr %1#1 : $*TwoField, #TwoField.a // user: %12
+  store %10 to %11 : $*Int                        // id: %12
+  %14 = integer_literal $Builtin.Int64, 20        // user: %15
+  %15 = struct $Int (%14 : $Builtin.Int64)        // user: %17
+  %16 = struct_element_addr %1#1 : $*TwoField, #TwoField.b // user: %17
+  store %15 to %16 : $*Int                        // id: %17
+  br bb3                                          // id: %13
+
+bb2:                                              // Preds: bb0
+  %3 = function_ref @init_twofield : $@convention(thin) (@thin TwoField.Type) -> TwoField // user: %5
+  %4 = metatype $@thin TwoField.Type              // user: %5
+  %5 = apply %3(%4) : $@convention(thin) (@thin TwoField.Type) -> TwoField // user: %6
+  store %5 to %1#1 : $*TwoField                   // id: %6
+  br bb3                                          // id: %18
+
+bb3:                                              // Preds: bb1 bb2
+  %99 = load %1#1 : $*TwoField                   // id: %6
+  %991 = function_ref @use_twofield : $@convention(thin) (TwoField) -> () // user: %5
+  %55 = apply %991(%99) : $@convention(thin) (TwoField) -> () // user: %6
+  %23 = tuple ()                                  // user: %25
+  dealloc_stack %1#0 : $*@local_storage TwoField  // id: %24
+  return %23 : $()                                // id: %25
+}