More codegen tests for enum discriminants

Author: scottmcm

tests/codegen/enum/enum-discriminant-eq.rs

@@ -0,0 +1,113 @@
+//@ compile-flags: -Copt-level=3 -Zmerge-functions=disabled
+
+// The `derive(PartialEq)` on enums with field-less variants compares discriminants,
+// so make sure we emit that in some reasonable way.
+
+#![crate_type = "lib"]
+#![feature(core_intrinsics)]
+#![feature(ascii_char)]
+
+use std::ascii::Char as AC;
+use std::cmp::Ordering;
+use std::intrinsics::discriminant_value;
+use std::num::NonZero;
+
+#[unsafe(no_mangle)]
+pub fn opt_bool_eq(a: Option<bool>, b: Option<bool>) -> bool {
+    // CHECK-LABEL: @opt_bool_eq(
+    // CHECK: %[[A:.+]] = icmp ne i8 %a, 2
+    // CHECK: %[[B:.+]] = icmp eq i8 %b, 2
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_ord_eq(a: Option<Ordering>, b: Option<Ordering>) -> bool {
+    // CHECK-LABEL: @opt_ord_eq(
+    // CHECK: %[[A:.+]] = icmp ne i8 %a, 2
+    // CHECK: %[[B:.+]] = icmp eq i8 %b, 2
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_nz32_eq(a: Option<NonZero<u32>>, b: Option<NonZero<u32>>) -> bool {
+    // CHECK-LABEL: @opt_nz32_eq(
+    // CHECK: %[[A:.+]] = icmp ne i32 %a, 0
+    // CHECK: %[[B:.+]] = icmp eq i32 %b, 0
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_ac_eq(a: Option<AC>, b: Option<AC>) -> bool {
+    // CHECK-LABEL: @opt_ac_eq(
+    // CHECK: %[[A:.+]] = icmp ne i8 %a, -128
+    // CHECK: %[[B:.+]] = icmp eq i8 %b, -128
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+pub enum Mid<T> {
+    Before,
+    Thing(T),
+    After,
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_bool_eq(a: Mid<bool>, b: Mid<bool>) -> bool {
+    // CHECK-LABEL: @mid_bool_eq(
+    // CHECK: %[[AS:.+]] = add nsw i8 %a, -2
+    // CHECK: %[[AT:.+]] = icmp ult i8 %[[AS]], 3
+    // CHECK: %[[AD:.+]] = select i1 %[[AT]], i8 %[[AS]], i8 1
+    // CHECK: %[[BS:.+]] = add nsw i8 %b, -2
+    // CHECK: %[[BT:.+]] = icmp ult i8 %[[BS]], 3
+    // CHECK: %[[BD:.+]] = select i1 %[[BT]], i8 %[[BS]], i8 1
+    // CHECK: %[[R:.+]] = icmp eq i8 %[[AD]], %[[BD]]
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_ord_eq(a: Mid<Ordering>, b: Mid<Ordering>) -> bool {
+    // CHECK-LABEL: @mid_ord_eq(
+    // CHECK: %[[AS:.+]] = add nsw i8 %a, -2
+    // CHECK: %[[AT:.+]] = icmp ult i8 %[[AS]], 3
+    // CHECK: %[[AD:.+]] = select i1 %[[AT]], i8 %[[AS]], i8 1
+    // CHECK: %[[BS:.+]] = add nsw i8 %b, -2
+    // CHECK: %[[BT:.+]] = icmp ult i8 %[[BS]], 3
+    // CHECK: %[[BD:.+]] = select i1 %[[BT]], i8 %[[BS]], i8 1
+    // CHECK: %[[R:.+]] = icmp eq i8 %[[AD]], %[[BD]]
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_nz32_eq(a: Mid<NonZero<u32>>, b: Mid<NonZero<u32>>) -> bool {
+    // CHECK-LABEL: @mid_nz32_eq(
+    // CHECK: %[[R:.+]] = icmp eq i32 %a.0, %b.0
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_ac_eq(a: Mid<AC>, b: Mid<AC>) -> bool {
+    // CHECK-LABEL: @mid_ac_eq(
+    // CHECK: %[[AS:.+]] = xor i8 %a, -128
+    // CHECK: %[[AT:.+]] = icmp ult i8 %[[AS]], 3
+    // CHECK: %[[AD:.+]] = select i1 %[[AT]], i8 %[[AS]], i8 1
+    // CHECK: %[[BS:.+]] = xor i8 %b, -128
+    // CHECK: %[[BT:.+]] = icmp ult i8 %[[BS]], 3
+    // CHECK: %[[BD:.+]] = select i1 %[[BT]], i8 %[[BS]], i8 1
+    // CHECK: %[[R:.+]] = icmp eq i8 %[[AD]], %[[BD]]
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}