1 files changed, 86 insertions, 0 deletions
diff --git a/tests/mir-opt/enum_opt.rs b/tests/mir-opt/enum_opt.rs
new file mode 100644
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+++ b/tests/mir-opt/enum_opt.rs
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+// unit-test: EnumSizeOpt
+// EMIT_MIR_FOR_EACH_BIT_WIDTH
+// compile-flags: -Zunsound-mir-opts
+
+#![feature(arbitrary_enum_discriminant, repr128)]
+
+// Tests that an enum with a variant with no data gets correctly transformed.
+pub enum NoData {
+  Large([u8; 8196]),
+  None,
+}
+
+// Tests that an enum with a variant with data that is a valid candidate gets transformed.
+pub enum Candidate {
+  Small(u8),
+  Large([u8; 8196]),
+}
+
+// Tests that an enum which has a discriminant much higher than the variant does not get
+// tformed.
+#[repr(u32)]
+pub enum InvalidIdxs {
+  A = 302,
+  Large([u64; 1024]),
+}
+
+// Tests that an enum with too high of a discriminant index (not in bounds of usize) does not
+// get tformed.
+#[repr(u128)]
+pub enum NotTrunctable {
+    A = 0,
+    B([u8; 1024]) = 1,
+    C([u8; 4096]) = 0x10000000000000001,
+}
+
+// Tests that an enum with discriminants in random order still gets tformed correctly.
+#[repr(u32)]
+pub enum RandOrderDiscr {
+  A = 13,
+  B([u8; 1024]) = 5,
+  C = 7,
+}
+
+// EMIT_MIR enum_opt.unin.EnumSizeOpt.diff
+pub fn unin() -> NoData {
+  let mut a = NoData::None;
+  a = NoData::Large([1; 8196]);
+  a
+}
+
+// EMIT_MIR enum_opt.cand.EnumSizeOpt.diff
+pub fn cand() -> Candidate {
+  let mut a = Candidate::Small(1);
+  a = Candidate::Large([1; 8196]);
+  a
+}
+
+// EMIT_MIR enum_opt.invalid.EnumSizeOpt.diff
+pub fn invalid() -> InvalidIdxs {
+  let mut a = InvalidIdxs::A;
+  a = InvalidIdxs::Large([0; 1024]);
+  a
+}
+
+// EMIT_MIR enum_opt.trunc.EnumSizeOpt.diff
+pub fn trunc() -> NotTrunctable {
+  let mut a = NotTrunctable::A;
+  a = NotTrunctable::B([0; 1024]);
+  a = NotTrunctable::C([0; 4096]);
+  a
+}
+
+pub fn rand_order() -> RandOrderDiscr {
+  let mut a = RandOrderDiscr::A;
+  a = RandOrderDiscr::B([0; 1024]);
+  a = RandOrderDiscr::C;
+  a
+}
+
+pub fn main() {
+  unin();
+  cand();
+  invalid();
+  trunc();
+  rand_order();
+}