3 files changed, 83 insertions, 29 deletions
diff --git a/src/test/codegen/match-optimized.rs b/src/test/codegen/match-optimized.rs
new file mode 100644
index 00000000000..36402cc7353
--- /dev/null
+++ b/src/test/codegen/match-optimized.rs
@@ -0,0 +1,60 @@
+// compile-flags: -C no-prepopulate-passes -O
+
+#![crate_type = "lib"]
+
+pub enum E {
+    A,
+    B,
+    C,
+}
+
+// CHECK-LABEL: @exhaustive_match
+#[no_mangle]
+pub fn exhaustive_match(e: E) -> u8 {
+// CHECK: switch{{.*}}, label %[[OTHERWISE:[a-zA-Z0-9_]+]] [
+// CHECK-NEXT: i[[TY:[0-9]+]] [[DISCR:[0-9]+]], label %[[A:[a-zA-Z0-9_]+]]
+// CHECK-NEXT: i[[TY:[0-9]+]] [[DISCR:[0-9]+]], label %[[B:[a-zA-Z0-9_]+]]
+// CHECK-NEXT: i[[TY:[0-9]+]] [[DISCR:[0-9]+]], label %[[C:[a-zA-Z0-9_]+]]
+// CHECK-NEXT: ]
+// CHECK: [[OTHERWISE]]:
+// CHECK-NEXT: unreachable
+//
+// CHECK: [[A]]:
+// CHECK-NEXT: store i8 0, {{i8\*|ptr}} %1, align 1
+// CHECK-NEXT: br label %[[EXIT:[a-zA-Z0-9_]+]]
+// CHECK: [[B]]:
+// CHECK-NEXT: store i8 1, {{i8\*|ptr}} %1, align 1
+// CHECK-NEXT: br label %[[EXIT]]
+// CHECK: [[C]]:
+// CHECK-NEXT: store i8 2, {{i8\*|ptr}} %1, align 1
+// CHECK-NEXT: br label %[[EXIT]]
+    match e {
+        E::A => 0,
+        E::B => 1,
+        E::C => 2,
+    }
+}
+
+#[repr(u16)]
+pub enum E2 {
+    A = 13,
+    B = 42,
+}
+
+// For optimized code we produce a switch with an unreachable target as the `otherwise` so LLVM
+// knows the possible values. Compare with `src/test/codegen/match-unoptimized.rs`.
+
+// CHECK-LABEL: @exhaustive_match_2
+#[no_mangle]
+pub fn exhaustive_match_2(e: E2) -> u8 {
+    // CHECK: switch i16 %{{.+}}, label %[[UNREACH:.+]] [
+    // CHECK-NEXT: i16 13,
+    // CHECK-NEXT: i16 42,
+    // CHECK-NEXT: ]
+    // CHECK: [[UNREACH]]:
+    // CHECK-NEXT: unreachable
+    match e {
+        E2::A => 0,
+        E2::B => 1,
+    }
+}
diff --git a/src/test/codegen/match-unoptimized.rs b/src/test/codegen/match-unoptimized.rs
new file mode 100644
index 00000000000..be40b29e3d3
--- /dev/null
+++ b/src/test/codegen/match-unoptimized.rs
@@ -0,0 +1,23 @@
+// compile-flags: -C no-prepopulate-passes -Copt-level=0
+
+#![crate_type = "lib"]
+
+#[repr(u16)]
+pub enum E2 {
+    A = 13,
+    B = 42,
+}
+
+// For unoptimized code we produce a `br` instead of a `switch`. Compare with
+// `src/test/codegen/match-optimized.rs`
+
+// CHECK-LABEL: @exhaustive_match_2
+#[no_mangle]
+pub fn exhaustive_match_2(e: E2) -> u8 {
+    // CHECK: %[[CMP:.+]] = icmp eq i16 %{{.+}}, 13
+    // CHECK-NEXT: br i1 %[[CMP:.+]],
+    match e {
+        E2::A => 0,
+        E2::B => 1,
+    }
+}
diff --git a/src/test/codegen/match.rs b/src/test/codegen/match.rs
deleted file mode 100644
index b203641fddb..00000000000
--- a/src/test/codegen/match.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-// compile-flags: -C no-prepopulate-passes
-
-#![crate_type = "lib"]
-
-pub enum E {
-    A,
-    B,
-}
-
-// CHECK-LABEL: @exhaustive_match
-#[no_mangle]
-pub fn exhaustive_match(e: E) -> u8 {
-// CHECK: switch{{.*}}, label %[[OTHERWISE:[a-zA-Z0-9_]+]] [
-// CHECK-NEXT: i[[TY:[0-9]+]] [[DISCR:[0-9]+]], label %[[A:[a-zA-Z0-9_]+]]
-// CHECK-NEXT: i[[TY:[0-9]+]] [[DISCR:[0-9]+]], label %[[B:[a-zA-Z0-9_]+]]
-// CHECK-NEXT: ]
-// CHECK: [[OTHERWISE]]:
-// CHECK-NEXT: unreachable
-// CHECK: [[A]]:
-// CHECK-NEXT: store i8 0, {{i8\*|ptr}} %1, align 1
-// CHECK-NEXT: br label %[[EXIT:[a-zA-Z0-9_]+]]
-// CHECK: [[B]]:
-// CHECK-NEXT: store i8 1, {{i8\*|ptr}} %1, align 1
-// CHECK-NEXT: br label %[[EXIT:[a-zA-Z0-9_]+]]
-    match e {
-        E::A => 0,
-        E::B => 1,
-    }
-}