Sort Eq candidates in the failure case too

compiler/rustc_mir_build/src/build/matches/test.rs

@@ -650,12 +650,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 }
             }
 
-            // FIXME(#29623): return `Some(1)` when the values are different.
-            (TestKind::Eq { value: test_val, .. }, TestCase::Constant { value: case_val })
-                if test_val == case_val =>
-            {
-                fully_matched = true;
-                Some(TestBranch::Success)
+            (TestKind::Eq { value: test_val, .. }, TestCase::Constant { value: case_val }) => {
+                if test_val == case_val {
+                    fully_matched = true;
+                    Some(TestBranch::Success)
+                } else {
+                    fully_matched = false;
+                    Some(TestBranch::Failure)
+                }
             }
 
             (

tests/mir-opt/building/match/sort_candidates.constant_eq.SimplifyCfg-initial.after.mir

@@ -9,10 +9,9 @@ fn constant_eq(_1: &str, _2: bool) -> u32 {
     let mut _5: bool;
     let mut _6: bool;
     let mut _7: bool;
-    let mut _8: bool;
-    let mut _9: &&str;
-    let mut _10: &bool;
-    let mut _11: bool;
+    let mut _8: &&str;
+    let mut _9: &bool;
+    let mut _10: bool;
 
     bb0: {
         StorageLive(_3);
@@ -24,104 +23,96 @@ fn constant_eq(_1: &str, _2: bool) -> u32 {
         StorageDead(_5);
         StorageDead(_4);
         PlaceMention(_3);
-        _8 = <str as PartialEq>::eq((_3.0: &str), const "a") -> [return: bb13, unwind: bb21];
+        _7 = <str as PartialEq>::eq((_3.0: &str), const "a") -> [return: bb11, unwind: bb19];
     }
 
     bb1: {
-        _7 = <str as PartialEq>::eq((_3.0: &str), const "b") -> [return: bb11, unwind: bb21];
+        switchInt((_3.1: bool)) -> [0: bb2, otherwise: bb3];
     }
 
     bb2: {
-        _6 = <str as PartialEq>::eq((_3.0: &str), const "a") -> [return: bb8, unwind: bb21];
+        _0 = const 5_u32;
+        goto -> bb18;
     }
 
     bb3: {
-        switchInt((_3.1: bool)) -> [0: bb4, otherwise: bb5];
+        falseEdge -> [real: bb17, imaginary: bb2];
     }
 
     bb4: {
-        _0 = const 5_u32;
-        goto -> bb20;
+        falseEdge -> [real: bb12, imaginary: bb9];
     }
 
     bb5: {
-        falseEdge -> [real: bb19, imaginary: bb4];
+        switchInt((_3.1: bool)) -> [0: bb1, otherwise: bb6];
     }
 
     bb6: {
-        switchInt((_3.1: bool)) -> [0: bb3, otherwise: bb7];
+        falseEdge -> [real: bb16, imaginary: bb3];
     }
 
     bb7: {
-        falseEdge -> [real: bb18, imaginary: bb5];
+        _6 = <str as PartialEq>::eq((_3.0: &str), const "b") -> [return: bb10, unwind: bb19];
     }
 
     bb8: {
-        switchInt(move _6) -> [0: bb3, otherwise: bb6];
+        switchInt((_3.1: bool)) -> [0: bb1, otherwise: bb9];
     }
 
     bb9: {
-        switchInt((_3.1: bool)) -> [0: bb2, otherwise: bb10];
+        falseEdge -> [real: bb15, imaginary: bb6];
     }
 
     bb10: {
-        falseEdge -> [real: bb17, imaginary: bb7];
+        switchInt(move _6) -> [0: bb1, otherwise: bb8];
     }
 
     bb11: {
-        switchInt(move _7) -> [0: bb2, otherwise: bb9];
+        switchInt(move _7) -> [0: bb7, otherwise: bb4];
     }
 
     bb12: {
-        falseEdge -> [real: bb14, imaginary: bb10];
+        _8 = &fake (_3.0: &str);
+        _9 = &fake (_3.1: bool);
+        StorageLive(_10);
+        _10 = const true;
+        switchInt(move _10) -> [0: bb14, otherwise: bb13];
     }
 
     bb13: {
-        switchInt(move _8) -> [0: bb1, otherwise: bb12];
+        StorageDead(_10);
+        FakeRead(ForMatchGuard, _8);
+        FakeRead(ForMatchGuard, _9);
+        _0 = const 1_u32;
+        goto -> bb18;
     }
 
     bb14: {
-        _9 = &fake (_3.0: &str);
-        _10 = &fake (_3.1: bool);
-        StorageLive(_11);
-        _11 = const true;
-        switchInt(move _11) -> [0: bb16, otherwise: bb15];
+        StorageDead(_10);
+        falseEdge -> [real: bb5, imaginary: bb9];
     }
 
     bb15: {
-        StorageDead(_11);
-        FakeRead(ForMatchGuard, _9);
-        FakeRead(ForMatchGuard, _10);
-        _0 = const 1_u32;
-        goto -> bb20;
+        _0 = const 2_u32;
+        goto -> bb18;
     }
 
     bb16: {
-        StorageDead(_11);
-        falseEdge -> [real: bb1, imaginary: bb10];
+        _0 = const 3_u32;
+        goto -> bb18;
     }
 
     bb17: {
-        _0 = const 2_u32;
-        goto -> bb20;
+        _0 = const 4_u32;
+        goto -> bb18;
     }
 
     bb18: {
-        _0 = const 3_u32;
-        goto -> bb20;
-    }
-
-    bb19: {
-        _0 = const 4_u32;
-        goto -> bb20;
-    }
-
-    bb20: {
         StorageDead(_3);
         return;
     }
 
-    bb21 (cleanup): {
+    bb19 (cleanup): {
         resume;
     }
 }

tests/mir-opt/building/match/sort_candidates.rs

@@ -4,7 +4,7 @@
 
 // EMIT_MIR sort_candidates.constant_eq.SimplifyCfg-initial.after.mir
 fn constant_eq(s: &str, b: bool) -> u32 {
-    // For now we test "a" twice.
+    // Check that we only test "a" once
     match (s, b) {
         ("a", _) if true => 1,
         ("b", true) => 2,