IRgen: Assignment to Objective-C properties shouldn't reload the value (which

would trigger an extra method call).
 - While in the area, I also changed Clang to not emit an unnecessary load from
   'x' in cases like 'y = (x = 1)'.

llvm-svn: 107210

1 files changed, 32 insertions, 0 deletions

diff --git a/clang/test/CodeGen/assign.c b/clang/test/CodeGen/assign.c
new file mode 100644
index 00000000000..eab3d357692
--- /dev/null
+++ b/clang/test/CodeGen/assign.c
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -triple x86_64 -emit-llvm -o - %s | FileCheck %s
+
+// Check that we don't generate unnecessary reloads.
+//
+// CHECK: define void @f0()
+// CHECK:      [[x_0:%.*]] = alloca i32, align 4
+// CHECK-NEXT: [[y_0:%.*]] = alloca i32, align 4
+// CHECK-NEXT: store i32 1, i32* [[x_0]]
+// CHECK-NEXT: store i32 1, i32* [[x_0]]
+// CHECK-NEXT: store i32 1, i32* [[y_0]]
+// CHECK: }
+void f0() {
+  int x, y;
+  x = 1;
+  y = (x = 1);
+}
+
+// Check that we do generate reloads for volatile access.
+//
+// CHECK: define void @f1()
+// CHECK:      [[x_1:%.*]] = alloca i32, align 4
+// CHECK-NEXT: [[y_1:%.*]] = alloca i32, align 4
+// CHECK-NEXT: volatile store i32 1, i32* [[x_1]]
+// CHECK-NEXT: volatile store i32 1, i32* [[x_1]]
+// CHECK-NEXT: [[tmp_1:%.*]] = volatile load i32* [[x_1]]
+// CHECK-NEXT: volatile store i32 [[tmp_1]], i32* [[y_1]]
+// CHECK: }
+void f1() {
+  volatile int x, y;
+  x = 1;
+  y = (x = 1);
+}