2 files changed, 74 insertions, 2 deletions
diff --git a/src/test/codegen/array-equality.rs b/src/test/codegen/array-equality.rs
new file mode 100644
index 00000000000..4b60fa4b0bf
--- /dev/null
+++ b/src/test/codegen/array-equality.rs
@@ -0,0 +1,57 @@
+// compile-flags: -O
+// only-x86_64
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @array_eq_value
+#[no_mangle]
+pub fn array_eq_value(a: [u16; 6], b: [u16; 6]) -> bool {
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %2 = icmp eq i96 %0, %1
+    // CHECK-NEXT: ret i1 %2
+    a == b
+}
+
+// CHECK-LABEL: @array_eq_ref
+#[no_mangle]
+pub fn array_eq_ref(a: &[u16; 6], b: &[u16; 6]) -> bool {
+    // CHECK: start:
+    // CHECK: load i96, i96* %{{.+}}, align 2
+    // CHECK: load i96, i96* %{{.+}}, align 2
+    // CHECK: icmp eq i96
+    // CHECK-NEXT: ret
+    a == b
+}
+
+// CHECK-LABEL: @array_eq_value_still_passed_by_pointer
+#[no_mangle]
+pub fn array_eq_value_still_passed_by_pointer(a: [u16; 9], b: [u16; 9]) -> bool {
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: bitcast
+    // CHECK-NEXT: bitcast
+    // CHECK-NEXT: %[[CMP:.+]] = tail call i32 @{{bcmp|memcmp}}(i8* nonnull dereferenceable(18) %{{.+}}, i8* nonnull dereferenceable(18) %{{.+}}, i64 18)
+    // CHECK-NEXT: %[[EQ:.+]] = icmp eq i32 %[[CMP]], 0
+    // CHECK-NEXT: ret i1 %[[EQ]]
+    a == b
+}
+
+// CHECK-LABEL: @array_eq_long
+#[no_mangle]
+pub fn array_eq_long(a: &[u16; 1234], b: &[u16; 1234]) -> bool {
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: bitcast
+    // CHECK-NEXT: bitcast
+    // CHECK-NEXT: %[[CMP:.+]] = tail call i32 @{{bcmp|memcmp}}(i8* nonnull dereferenceable(2468) %{{.+}}, i8* nonnull dereferenceable(2468) %{{.+}}, i64 2468)
+    // CHECK-NEXT: %[[EQ:.+]] = icmp eq i32 %[[CMP]], 0
+    // CHECK-NEXT: ret i1 %[[EQ]]
+    a == b
+}
+
+// CHECK-LABEL: @array_eq_zero(i128 %0)
+#[no_mangle]
+pub fn array_eq_zero(x: [u16; 8]) -> bool {
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %[[EQ:.+]] = icmp eq i128 %0, 0
+    // CHECK-NEXT: ret i1 %[[EQ]]
+    x == [0; 8]
+}
diff --git a/src/test/codegen/slice-ref-equality.rs b/src/test/codegen/slice-ref-equality.rs
index acc7879e7b1..1f99ac7342b 100644
--- a/src/test/codegen/slice-ref-equality.rs
+++ b/src/test/codegen/slice-ref-equality.rs
@@ -2,15 +2,30 @@
 
 #![crate_type = "lib"]
 
-// #71602: check that slice equality just generates a single bcmp
+// #71602 reported a simple array comparison just generating a loop.
+// This was originally fixed by ensuring it generates a single bcmp,
+// but we now generate it as a load instead. `is_zero_slice` was
+// tweaked to still test the case of comparison against a slice,
+// and `is_zero_array` tests the new array-specific behaviour.
 
 // CHECK-LABEL: @is_zero_slice
 #[no_mangle]
 pub fn is_zero_slice(data: &[u8; 4]) -> bool {
-    // CHECK: start:
+    // CHECK: :
     // CHECK-NEXT: %{{.+}} = getelementptr {{.+}}
     // CHECK-NEXT: %[[BCMP:.+]] = tail call i32 @{{bcmp|memcmp}}({{.+}})
     // CHECK-NEXT: %[[EQ:.+]] = icmp eq i32 %[[BCMP]], 0
     // CHECK-NEXT: ret i1 %[[EQ]]
+    &data[..] == [0; 4]
+}
+
+// CHECK-LABEL: @is_zero_array
+#[no_mangle]
+pub fn is_zero_array(data: &[u8; 4]) -> bool {
+    // CHECK: start:
+    // CHECK-NEXT: %[[PTR:.+]] = bitcast [4 x i8]* {{.+}} to i32*
+    // CHECK-NEXT: %[[LOAD:.+]] = load i32, i32* %[[PTR]], align 1
+    // CHECK-NEXT: %[[EQ:.+]] = icmp eq i32 %[[LOAD]], 0
+    // CHECK-NEXT: ret i1 %[[EQ]]
     *data == [0; 4]
 }