diff --git a/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff.32bit b/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff.32bit
new file mode 100644
index 00000000000..df94c897e92
--- /dev/null
+++ b/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff.32bit
@@ -0,0 +1,66 @@
+- // MIR for `foo` before MatchBranchSimplification
++ // MIR for `foo` after MatchBranchSimplification
+  
+  fn foo(_1: std::option::Option<()>) -> () {
+      debug bar => _1;                     // in scope 0 at $DIR/matches_reduce_branches.rs:4:8: 4:11
+      let mut _0: ();                      // return place in scope 0 at $DIR/matches_reduce_branches.rs:4:25: 4:25
+      let mut _2: bool;                    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+      let mut _3: isize;                   // in scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+          _3 = discriminant(_1);           // scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
+-         switchInt(move _3) -> [0_isize: bb2, otherwise: bb1]; // scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
++         _2 = Eq(move _3, const 0_isize); // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
++                                          // ty::Const
++                                          // + ty: isize
++                                          // + val: Value(Scalar(0x00000000))
++                                          // mir::Constant
++                                          // + span: $DIR/matches_reduce_branches.rs:1:1: 1:1
++                                          // + literal: Const { ty: isize, val: Value(Scalar(0x00000000)) }
++         goto -> bb3;                     // scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
+      }
+  
+      bb1: {
+          _2 = const false;                // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: bool
+                                           // + val: Value(Scalar(0x00))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: bool, val: Value(Scalar(0x00)) }
+          goto -> bb3;                     // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+      }
+  
+      bb2: {
+          _2 = const true;                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+                                           // ty::Const
+                                           // + ty: bool
+                                           // + val: Value(Scalar(0x01))
+                                           // mir::Constant
+                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: bool, val: Value(Scalar(0x01)) }
+          goto -> bb3;                     // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+      }
+  
+      bb3: {
+          switchInt(_2) -> [false: bb4, otherwise: bb5]; // scope 0 at $DIR/matches_reduce_branches.rs:5:5: 7:6
+      }
+  
+      bb4: {
+          _0 = const ();                   // scope 0 at $DIR/matches_reduce_branches.rs:5:5: 7:6
+                                           // ty::Const
+                                           // + ty: ()
+                                           // + val: Value(Scalar(<ZST>))
+                                           // mir::Constant
+                                           // + span: $DIR/matches_reduce_branches.rs:5:5: 7:6
+                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
+          goto -> bb5;                     // scope 0 at $DIR/matches_reduce_branches.rs:5:5: 7:6
+      }
+  
+      bb5: {
+          StorageDead(_2);                 // scope 0 at $DIR/matches_reduce_branches.rs:8:1: 8:2
+          return;                          // scope 0 at $DIR/matches_reduce_branches.rs:8:2: 8:2
+      }
+  }
+  
diff --git a/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff b/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff.64bit
similarity index 75%
rename from src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff
rename to src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff.64bit
index b0a861f6c5e..06849b4a5d9 100644
--- a/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff
+++ b/src/test/mir-opt/matches_reduce_branches.foo.MatchBranchSimplification.diff.64bit
@@ -2,16 +2,23 @@
 + // MIR for `foo` after MatchBranchSimplification
   
   fn foo(_1: std::option::Option<()>) -> () {
-      debug bar => _1;                     // in scope 0 at $DIR/matches_reduce_branches.rs:3:8: 3:11
-      let mut _0: ();                      // return place in scope 0 at $DIR/matches_reduce_branches.rs:3:25: 3:25
+      debug bar => _1;                     // in scope 0 at $DIR/matches_reduce_branches.rs:4:8: 4:11
+      let mut _0: ();                      // return place in scope 0 at $DIR/matches_reduce_branches.rs:4:25: 4:25
       let mut _2: bool;                    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _3: isize;                   // in scope 0 at $DIR/matches_reduce_branches.rs:4:22: 4:26
+      let mut _3: isize;                   // in scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
   
       bb0: {
           StorageLive(_2);                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-          _3 = discriminant(_1);           // scope 0 at $DIR/matches_reduce_branches.rs:4:22: 4:26
--         switchInt(move _3) -> [0_isize: bb2, otherwise: bb1]; // scope 0 at $DIR/matches_reduce_branches.rs:4:22: 4:26
-+         goto -> bb2;                     // scope 0 at $DIR/matches_reduce_branches.rs:4:22: 4:26
+          _3 = discriminant(_1);           // scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
+-         switchInt(move _3) -> [0_isize: bb2, otherwise: bb1]; // scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
++         _2 = Eq(move _3, const 0_isize); // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
++                                          // ty::Const
++                                          // + ty: isize
++                                          // + val: Value(Scalar(0x0000000000000000))
++                                          // mir::Constant
++                                          // + span: $DIR/matches_reduce_branches.rs:1:1: 1:1
++                                          // + literal: Const { ty: isize, val: Value(Scalar(0x0000000000000000)) }
++         goto -> bb3;                     // scope 0 at $DIR/matches_reduce_branches.rs:5:22: 5:26
       }
   
       bb1: {
@@ -26,39 +33,34 @@
       }
   
       bb2: {
--         _2 = const true;                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-+         _2 = Eq(move _3, const 0_isize); // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+          _2 = const true;                 // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
                                            // ty::Const
--                                          // + ty: bool
--                                          // + val: Value(Scalar(0x01))
-+                                          // + ty: isize
-+                                          // + val: Value(Scalar(0x0000000000000000))
+                                           // + ty: bool
+                                           // + val: Value(Scalar(0x01))
                                            // mir::Constant
--                                          // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
--                                          // + literal: Const { ty: bool, val: Value(Scalar(0x01)) }
-+                                          // + span: $DIR/matches_reduce_branches.rs:1:1: 1:1
-+                                          // + literal: Const { ty: isize, val: Value(Scalar(0x0000000000000000)) }
+                                           // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
+                                           // + literal: Const { ty: bool, val: Value(Scalar(0x01)) }
           goto -> bb3;                     // scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
       }
   
       bb3: {
-          switchInt(_2) -> [false: bb4, otherwise: bb5]; // scope 0 at $DIR/matches_reduce_branches.rs:4:5: 6:6
+          switchInt(_2) -> [false: bb4, otherwise: bb5]; // scope 0 at $DIR/matches_reduce_branches.rs:5:5: 7:6
       }
   
       bb4: {
-          _0 = const ();                   // scope 0 at $DIR/matches_reduce_branches.rs:4:5: 6:6
+          _0 = const ();                   // scope 0 at $DIR/matches_reduce_branches.rs:5:5: 7:6
                                            // ty::Const
                                            // + ty: ()
                                            // + val: Value(Scalar(<ZST>))
                                            // mir::Constant
-                                           // + span: $DIR/matches_reduce_branches.rs:4:5: 6:6
+                                           // + span: $DIR/matches_reduce_branches.rs:5:5: 7:6
                                            // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
-          goto -> bb5;                     // scope 0 at $DIR/matches_reduce_branches.rs:4:5: 6:6
+          goto -> bb5;                     // scope 0 at $DIR/matches_reduce_branches.rs:5:5: 7:6
       }
   
       bb5: {
-          StorageDead(_2);                 // scope 0 at $DIR/matches_reduce_branches.rs:7:1: 7:2
-          return;                          // scope 0 at $DIR/matches_reduce_branches.rs:7:2: 7:2
+          StorageDead(_2);                 // scope 0 at $DIR/matches_reduce_branches.rs:8:1: 8:2
+          return;                          // scope 0 at $DIR/matches_reduce_branches.rs:8:2: 8:2
       }
   }
   
diff --git a/src/test/mir-opt/matches_reduce_branches.rs b/src/test/mir-opt/matches_reduce_branches.rs
index 2d1a6d8de21..91b6bfc836b 100644
--- a/src/test/mir-opt/matches_reduce_branches.rs
+++ b/src/test/mir-opt/matches_reduce_branches.rs
@@ -1,3 +1,4 @@
+// EMIT_MIR_FOR_EACH_BIT_WIDTH
 // EMIT_MIR matches_reduce_branches.foo.MatchBranchSimplification.diff
 
 fn foo(bar: Option<()>) {