interpret: simplify handling of shifts by no longer trying to handle signed and unsigned shift amounts in the same branch

2 files changed, 24 insertions, 0 deletions

diff --git a/src/tools/miri/tests/fail/intrinsics/unchecked_shl2.rs b/src/tools/miri/tests/fail/intrinsics/unchecked_shl2.rs
new file mode 100644
index 00000000000..a5777ebbb7f
--- /dev/null
+++ b/src/tools/miri/tests/fail/intrinsics/unchecked_shl2.rs
@@ -0,0 +1,9 @@
+#![feature(core_intrinsics)]
+use std::intrinsics;
+
+fn main() {
+    unsafe {
+        let _n = intrinsics::unchecked_shl(1i8, -1);
+        //~^ ERROR: overflowing shift by -1 in `unchecked_shl`
+    }
+}
diff --git a/src/tools/miri/tests/fail/intrinsics/unchecked_shl2.stderr b/src/tools/miri/tests/fail/intrinsics/unchecked_shl2.stderr
new file mode 100644
index 00000000000..ab27c9fe911
--- /dev/null
+++ b/src/tools/miri/tests/fail/intrinsics/unchecked_shl2.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: overflowing shift by -1 in `unchecked_shl`
+  --> $DIR/unchecked_shl2.rs:LL:CC
+   |
+LL |         let _n = intrinsics::unchecked_shl(1i8, -1);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ overflowing shift by -1 in `unchecked_shl`
+   |
+   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+   = note: BACKTRACE:
+   = note: inside `main` at $DIR/unchecked_shl2.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to previous error
+