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-rw-r--r--gcc/testsuite/rust/compile/black_box.rs28
1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/testsuite/rust/compile/black_box.rs b/gcc/testsuite/rust/compile/black_box.rs
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+++ b/gcc/testsuite/rust/compile/black_box.rs
@@ -0,0 +1,28 @@
+// { dg-options "-fdump-tree-gimple" }
+#![feature(rustc_attrs)]
+
+#[lang = "sized"]
+pub trait Sized {}
+
+#[rustc_builtin_macro]
+macro_rules! llvm_asm {
+ () => {};
+}
+
+pub fn black_box<T>(mut dummy: T) -> T {
+ unsafe {
+ // { dg-final { scan-tree-dump-times {memory} 1 gimple } }
+ llvm_asm!("" : : "r"(&mut dummy) : "memory" : "volatile");
+ }
+
+ dummy
+}
+
+fn my_function(a: i32) -> i32 {
+ a
+}
+
+fn main() {
+ let dummy: i32 = 42;
+ let _ = black_box(my_function(dummy));
+}