1 files changed, 74 insertions, 0 deletions
diff --git a/tests/codegen-llvm/array-cmp.rs b/tests/codegen-llvm/array-cmp.rs
new file mode 100644
index 00000000000..0d337655401
--- /dev/null
+++ b/tests/codegen-llvm/array-cmp.rs
@@ -0,0 +1,74 @@
+// Ensure the asm for array comparisons is properly optimized.
+
+//@ compile-flags: -C opt-level=2
+//@ needs-deterministic-layouts (checks depend on tuple layout)
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @compare
+// CHECK: start:
+// CHECK-NEXT: ret i1 true
+#[no_mangle]
+pub fn compare() -> bool {
+    let bytes = 12.5f32.to_ne_bytes();
+    bytes
+        == if cfg!(target_endian = "big") {
+            [0x41, 0x48, 0x00, 0x00]
+        } else {
+            [0x00, 0x00, 0x48, 0x41]
+        }
+}
+
+// CHECK-LABEL: @array_of_tuple_le
+#[no_mangle]
+pub fn array_of_tuple_le(a: &[(i16, u16); 2], b: &[(i16, u16); 2]) -> bool {
+    // Ensure that, after all the optimizations have run, the happy path just checks
+    // `eq` on each corresponding pair and moves onto the next one if it is.
+    // Then there's a dedup'd comparison for the place that's different.
+    // (As opposed to, say, running a full `[su]cmp` as part of checking equality.)
+
+    // This is written quite specifically because different library code was triggering
+    // <https://github.com/llvm/llvm-project/issues/132678> along the way, so this
+    // has enough checks to make sure that's not happening. It doesn't need to be
+    // *exactly* this IR, but be careful if you ever need to update these checks.
+
+    // CHECK: start:
+    // CHECK: %[[A00:.+]] = load i16, ptr %a
+    // CHECK: %[[B00:.+]] = load i16, ptr %b
+    // CHECK-NOT: cmp
+    // CHECK: %[[EQ00:.+]] = icmp eq i16 %[[A00]], %[[B00]]
+    // CHECK-NEXT: br i1 %[[EQ00]], label %[[L01:.+]], label %[[EXIT_S:.+]]
+
+    // CHECK: [[L01]]:
+    // CHECK: %[[PA01:.+]] = getelementptr{{.+}}i8, ptr %a, {{i32|i64}} 2
+    // CHECK: %[[PB01:.+]] = getelementptr{{.+}}i8, ptr %b, {{i32|i64}} 2
+    // CHECK: %[[A01:.+]] = load i16, ptr %[[PA01]]
+    // CHECK: %[[B01:.+]] = load i16, ptr %[[PB01]]
+    // CHECK-NOT: cmp
+    // CHECK: %[[EQ01:.+]] = icmp eq i16 %[[A01]], %[[B01]]
+    // CHECK-NEXT: br i1 %[[EQ01]], label %[[L10:.+]], label %[[EXIT_U:.+]]
+
+    // CHECK: [[L10]]:
+    // CHECK: %[[PA10:.+]] = getelementptr{{.+}}i8, ptr %a, {{i32|i64}} 4
+    // CHECK: %[[PB10:.+]] = getelementptr{{.+}}i8, ptr %b, {{i32|i64}} 4
+    // CHECK: %[[A10:.+]] = load i16, ptr %[[PA10]]
+    // CHECK: %[[B10:.+]] = load i16, ptr %[[PB10]]
+    // CHECK-NOT: cmp
+    // CHECK: %[[EQ10:.+]] = icmp eq i16 %[[A10]], %[[B10]]
+    // CHECK-NEXT: br i1 %[[EQ10]], label %[[L11:.+]], label %[[EXIT_S]]
+
+    // CHECK: [[L11]]:
+    // CHECK: %[[PA11:.+]] = getelementptr{{.+}}i8, ptr %a, {{i32|i64}} 6
+    // CHECK: %[[PB11:.+]] = getelementptr{{.+}}i8, ptr %b, {{i32|i64}} 6
+    // CHECK: %[[A11:.+]] = load i16, ptr %[[PA11]]
+    // CHECK: %[[B11:.+]] = load i16, ptr %[[PB11]]
+    // CHECK-NOT: cmp
+    // CHECK: %[[EQ11:.+]] = icmp eq i16 %[[A11]], %[[B11]]
+    // CHECK-NEXT: br i1 %[[EQ11]], label %[[DONE:.+]], label %[[EXIT_U]]
+
+    // CHECK: [[DONE]]:
+    // CHECK: %[[RET:.+]] = phi i1 [ %{{.+}}, %[[EXIT_S]] ], [ %{{.+}}, %[[EXIT_U]] ], [ true, %[[L11]] ]
+    // CHECK: ret i1 %[[RET]]
+
+    a <= b
+}