Implement JumpThreading pass.

1 files changed, 87 insertions, 0 deletions

diff --git a/tests/mir-opt/jump_threading.dfa.JumpThreading.panic-unwind.diff b/tests/mir-opt/jump_threading.dfa.JumpThreading.panic-unwind.diff
new file mode 100644
index 00000000000..bad733268a3
--- /dev/null
+++ b/tests/mir-opt/jump_threading.dfa.JumpThreading.panic-unwind.diff
@@ -0,0 +1,87 @@
+- // MIR for `dfa` before JumpThreading
++ // MIR for `dfa` after JumpThreading
+  
+  fn dfa() -> () {
+      let mut _0: ();
+      let mut _1: DFA;
+      let mut _2: !;
+      let mut _3: ();
+      let mut _4: isize;
+      let mut _5: DFA;
+      let mut _6: DFA;
+      let mut _7: DFA;
+      let mut _8: !;
+      scope 1 {
+          debug state => _1;
+      }
+  
+      bb0: {
+          StorageLive(_1);
+          _1 = DFA::A;
+          StorageLive(_2);
+-         goto -> bb1;
++         goto -> bb7;
+      }
+  
+      bb1: {
+          _4 = discriminant(_1);
+-         switchInt(move _4) -> [0: bb4, 1: bb5, 2: bb6, 3: bb2, otherwise: bb3];
++         goto -> bb2;
+      }
+  
+      bb2: {
+          _0 = const ();
+          StorageDead(_2);
+          StorageDead(_1);
+          return;
+      }
+  
+      bb3: {
+          unreachable;
+      }
+  
+      bb4: {
+          StorageLive(_5);
+          _5 = DFA::B;
+          _1 = move _5;
+          _3 = const ();
+          StorageDead(_5);
+-         goto -> bb1;
++         goto -> bb8;
+      }
+  
+      bb5: {
+          StorageLive(_6);
+          _6 = DFA::C;
+          _1 = move _6;
+          _3 = const ();
+          StorageDead(_6);
+-         goto -> bb1;
++         goto -> bb9;
+      }
+  
+      bb6: {
+          StorageLive(_7);
+          _7 = DFA::D;
+          _1 = move _7;
+          _3 = const ();
+          StorageDead(_7);
+          goto -> bb1;
++     }
++ 
++     bb7: {
++         _4 = discriminant(_1);
++         goto -> bb4;
++     }
++ 
++     bb8: {
++         _4 = discriminant(_1);
++         goto -> bb5;
++     }
++ 
++     bb9: {
++         _4 = discriminant(_1);
++         goto -> bb6;
+      }
+  }
+