Switch optimizations in remove-unused-brs (#1753)

* Switch optimizations in remove-unused-brs: thread switch jumps, and turn a switch with all identical targets into a br

* refinalize in interm operations in remove-unused-brs, as we can be confused by it

9 files changed, 212 insertions, 125 deletions

diff --git a/test/emcc_hello_world.fromasm b/test/emcc_hello_world.fromasm
index cb9b99b74..e70998db0 100644
--- a/test/emcc_hello_world.fromasm
+++ b/test/emcc_hello_world.fromasm
@@ -3309,19 +3309,19 @@
              (block $__rjti$4
               (block $__rjti$3
                (block $switch-default120
-                (block $switch-case42
+                (block $switch-case119
                  (block $switch-case41
                   (block $switch-case40
                    (block $switch-case39
                     (block $switch-case38
                      (block $switch-case37
                       (block $switch-case36
-                       (block $switch-case34
+                       (block $switch-case35
                         (block $switch-case33
-                         (block $switch-case29
+                         (block $switch-case30
                           (block $switch-case28
                            (block $switch-case27
-                            (br_table $switch-case42 $switch-default120 $switch-case40 $switch-default120 $switch-case42 $switch-case42 $switch-case42 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case41 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case29 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case42 $switch-default120 $switch-case37 $switch-case34 $switch-case42 $switch-case42 $switch-case42 $switch-default120 $switch-case34 $switch-default120 $switch-default120 $switch-default120 $switch-case38 $switch-case27 $switch-case33 $switch-case28 $switch-default120 $switch-default120 $switch-case39 $switch-default120 $switch-case36 $switch-default120 $switch-default120 $switch-case29 $switch-default120
+                            (br_table $switch-case119 $switch-default120 $switch-case40 $switch-default120 $switch-case119 $switch-case119 $switch-case119 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case41 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case30 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case119 $switch-default120 $switch-case37 $switch-case35 $switch-case119 $switch-case119 $switch-case119 $switch-default120 $switch-case35 $switch-default120 $switch-default120 $switch-default120 $switch-case38 $switch-case27 $switch-case33 $switch-case28 $switch-default120 $switch-default120 $switch-case39 $switch-default120 $switch-case36 $switch-default120 $switch-default120 $switch-case30 $switch-default120
                              (i32.sub
                               (tee_local $19
                                (select
@@ -6915,7 +6915,7 @@
     (get_local $1)
     (i32.const 20)
    )
-   (block $switch-default
+   (block $label$break$L1
     (block $switch-case9
      (block $switch-case8
       (block $switch-case7
@@ -6926,7 +6926,7 @@
            (block $switch-case2
             (block $switch-case1
              (block $switch-case
-              (br_table $switch-case $switch-case1 $switch-case2 $switch-case3 $switch-case4 $switch-case5 $switch-case6 $switch-case7 $switch-case8 $switch-case9 $switch-default
+              (br_table $switch-case $switch-case1 $switch-case2 $switch-case3 $switch-case4 $switch-case5 $switch-case6 $switch-case7 $switch-case8 $switch-case9 $label$break$L1
                (i32.sub
                 (get_local $1)
                 (i32.const 9)
@@ -6959,7 +6959,7 @@
               (get_local $0)
               (get_local $3)
              )
-             (br $switch-default)
+             (br $label$break$L1)
             )
             (set_local $1
              (i32.load
@@ -7000,7 +7000,7 @@
               (i32.const 31)
              )
             )
-            (br $switch-default)
+            (br $label$break$L1)
            )
            (set_local $3
             (i32.load
@@ -7032,7 +7032,7 @@
             (get_local $0)
             (i32.const 0)
            )
-           (br $switch-default)
+           (br $label$break$L1)
           )
           (set_local $5
            (i32.load
@@ -7071,7 +7071,7 @@
            (get_local $0)
            (get_local $3)
           )
-          (br $switch-default)
+          (br $label$break$L1)
          )
          (set_local $3
           (i32.load
@@ -7123,7 +7123,7 @@
            (i32.const 31)
           )
          )
-         (br $switch-default)
+         (br $label$break$L1)
         )
         (set_local $3
          (i32.load
@@ -7158,7 +7158,7 @@
          (get_local $0)
          (i32.const 0)
         )
-        (br $switch-default)
+        (br $label$break$L1)
        )
        (set_local $3
         (i32.load
@@ -7210,7 +7210,7 @@
          (i32.const 31)
         )
        )
-       (br $switch-default)
+       (br $label$break$L1)
       )
       (set_local $3
        (i32.load
@@ -7245,7 +7245,7 @@
        (get_local $0)
        (i32.const 0)
       )
-      (br $switch-default)
+      (br $label$break$L1)
      )
      (set_local $4
       (f64.load
@@ -7273,7 +7273,7 @@
       (get_local $0)
       (get_local $4)
      )
-     (br $switch-default)
+     (br $label$break$L1)
     )
     (set_local $4
      (f64.load
diff --git a/test/emcc_hello_world.fromasm.clamp b/test/emcc_hello_world.fromasm.clamp
index dafa2db7b..244f8adba 100644
--- a/test/emcc_hello_world.fromasm.clamp
+++ b/test/emcc_hello_world.fromasm.clamp
@@ -3359,19 +3359,19 @@
              (block $__rjti$4
               (block $__rjti$3
                (block $switch-default120
-                (block $switch-case42
+                (block $switch-case119
                  (block $switch-case41
                   (block $switch-case40
                    (block $switch-case39
                     (block $switch-case38
                      (block $switch-case37
                       (block $switch-case36
-                       (block $switch-case34
+                       (block $switch-case35
                         (block $switch-case33
-                         (block $switch-case29
+                         (block $switch-case30
                           (block $switch-case28
                            (block $switch-case27
-                            (br_table $switch-case42 $switch-default120 $switch-case40 $switch-default120 $switch-case42 $switch-case42 $switch-case42 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case41 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case29 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case42 $switch-default120 $switch-case37 $switch-case34 $switch-case42 $switch-case42 $switch-case42 $switch-default120 $switch-case34 $switch-default120 $switch-default120 $switch-default120 $switch-case38 $switch-case27 $switch-case33 $switch-case28 $switch-default120 $switch-default120 $switch-case39 $switch-default120 $switch-case36 $switch-default120 $switch-default120 $switch-case29 $switch-default120
+                            (br_table $switch-case119 $switch-default120 $switch-case40 $switch-default120 $switch-case119 $switch-case119 $switch-case119 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case41 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case30 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case119 $switch-default120 $switch-case37 $switch-case35 $switch-case119 $switch-case119 $switch-case119 $switch-default120 $switch-case35 $switch-default120 $switch-default120 $switch-default120 $switch-case38 $switch-case27 $switch-case33 $switch-case28 $switch-default120 $switch-default120 $switch-case39 $switch-default120 $switch-case36 $switch-default120 $switch-default120 $switch-case30 $switch-default120
                              (i32.sub
                               (tee_local $19
                                (select
@@ -6965,7 +6965,7 @@
     (get_local $1)
     (i32.const 20)
    )
-   (block $switch-default
+   (block $label$break$L1
     (block $switch-case9
      (block $switch-case8
       (block $switch-case7
@@ -6976,7 +6976,7 @@
            (block $switch-case2
             (block $switch-case1
              (block $switch-case
-              (br_table $switch-case $switch-case1 $switch-case2 $switch-case3 $switch-case4 $switch-case5 $switch-case6 $switch-case7 $switch-case8 $switch-case9 $switch-default
+              (br_table $switch-case $switch-case1 $switch-case2 $switch-case3 $switch-case4 $switch-case5 $switch-case6 $switch-case7 $switch-case8 $switch-case9 $label$break$L1
                (i32.sub
                 (get_local $1)
                 (i32.const 9)
@@ -7009,7 +7009,7 @@
               (get_local $0)
               (get_local $3)
              )
-             (br $switch-default)
+             (br $label$break$L1)
             )
             (set_local $1
              (i32.load
@@ -7050,7 +7050,7 @@
               (i32.const 31)
              )
             )
-            (br $switch-default)
+            (br $label$break$L1)
            )
            (set_local $3
             (i32.load
@@ -7082,7 +7082,7 @@
             (get_local $0)
             (i32.const 0)
            )
-           (br $switch-default)
+           (br $label$break$L1)
           )
           (set_local $5
            (i32.load
@@ -7121,7 +7121,7 @@
            (get_local $0)
            (get_local $3)
           )
-          (br $switch-default)
+          (br $label$break$L1)
          )
          (set_local $3
           (i32.load
@@ -7173,7 +7173,7 @@
            (i32.const 31)
           )
          )
-         (br $switch-default)
+         (br $label$break$L1)
         )
         (set_local $3
          (i32.load
@@ -7208,7 +7208,7 @@
          (get_local $0)
          (i32.const 0)
         )
-        (br $switch-default)
+        (br $label$break$L1)
        )
        (set_local $3
         (i32.load
@@ -7260,7 +7260,7 @@
          (i32.const 31)
         )
        )
-       (br $switch-default)
+       (br $label$break$L1)
       )
       (set_local $3
        (i32.load
@@ -7295,7 +7295,7 @@
        (get_local $0)
        (i32.const 0)
       )
-      (br $switch-default)
+      (br $label$break$L1)
      )
      (set_local $4
       (f64.load
@@ -7323,7 +7323,7 @@
       (get_local $0)
       (get_local $4)
      )
-     (br $switch-default)
+     (br $label$break$L1)
     )
     (set_local $4
      (f64.load
diff --git a/test/emcc_hello_world.fromasm.imprecise b/test/emcc_hello_world.fromasm.imprecise
index ed05f6905..5cfa87fe1 100644
--- a/test/emcc_hello_world.fromasm.imprecise
+++ b/test/emcc_hello_world.fromasm.imprecise
@@ -3249,19 +3249,19 @@
              (block $__rjti$4
               (block $__rjti$3
                (block $switch-default120
-                (block $switch-case42
+                (block $switch-case119
                  (block $switch-case41
                   (block $switch-case40
                    (block $switch-case39
                     (block $switch-case38
                      (block $switch-case37
                       (block $switch-case36
-                       (block $switch-case34
+                       (block $switch-case35
                         (block $switch-case33
-                         (block $switch-case29
+                         (block $switch-case30
                           (block $switch-case28
                            (block $switch-case27
-                            (br_table $switch-case42 $switch-default120 $switch-case40 $switch-default120 $switch-case42 $switch-case42 $switch-case42 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case41 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case29 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case42 $switch-default120 $switch-case37 $switch-case34 $switch-case42 $switch-case42 $switch-case42 $switch-default120 $switch-case34 $switch-default120 $switch-default120 $switch-default120 $switch-case38 $switch-case27 $switch-case33 $switch-case28 $switch-default120 $switch-default120 $switch-case39 $switch-default120 $switch-case36 $switch-default120 $switch-default120 $switch-case29 $switch-default120
+                            (br_table $switch-case119 $switch-default120 $switch-case40 $switch-default120 $switch-case119 $switch-case119 $switch-case119 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case41 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case30 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-default120 $switch-case119 $switch-default120 $switch-case37 $switch-case35 $switch-case119 $switch-case119 $switch-case119 $switch-default120 $switch-case35 $switch-default120 $switch-default120 $switch-default120 $switch-case38 $switch-case27 $switch-case33 $switch-case28 $switch-default120 $switch-default120 $switch-case39 $switch-default120 $switch-case36 $switch-default120 $switch-default120 $switch-case30 $switch-default120
                              (i32.sub
                               (tee_local $19
                                (select
@@ -6829,7 +6829,7 @@
     (get_local $1)
     (i32.const 20)
    )
-   (block $switch-default
+   (block $label$break$L1
     (block $switch-case9
      (block $switch-case8
       (block $switch-case7
@@ -6840,7 +6840,7 @@
            (block $switch-case2
             (block $switch-case1
              (block $switch-case
-              (br_table $switch-case $switch-case1 $switch-case2 $switch-case3 $switch-case4 $switch-case5 $switch-case6 $switch-case7 $switch-case8 $switch-case9 $switch-default
+              (br_table $switch-case $switch-case1 $switch-case2 $switch-case3 $switch-case4 $switch-case5 $switch-case6 $switch-case7 $switch-case8 $switch-case9 $label$break$L1
                (i32.sub
                 (get_local $1)
                 (i32.const 9)
@@ -6873,7 +6873,7 @@
               (get_local $0)
               (get_local $3)
              )
-             (br $switch-default)
+             (br $label$break$L1)
             )
             (set_local $1
              (i32.load
@@ -6914,7 +6914,7 @@
               (i32.const 31)
              )
             )
-            (br $switch-default)
+            (br $label$break$L1)
            )
            (set_local $3
             (i32.load
@@ -6946,7 +6946,7 @@
             (get_local $0)
             (i32.const 0)
            )
-           (br $switch-default)
+           (br $label$break$L1)
           )
           (set_local $5
            (i32.load
@@ -6985,7 +6985,7 @@
            (get_local $0)
            (get_local $3)
           )
-          (br $switch-default)
+          (br $label$break$L1)
          )
          (set_local $3
           (i32.load
@@ -7037,7 +7037,7 @@
            (i32.const 31)
           )
          )
-         (br $switch-default)
+         (br $label$break$L1)
         )
         (set_local $3
          (i32.load
@@ -7072,7 +7072,7 @@
          (get_local $0)
          (i32.const 0)
         )
-        (br $switch-default)
+        (br $label$break$L1)
        )
        (set_local $3
         (i32.load
@@ -7124,7 +7124,7 @@
          (i32.const 31)
         )
        )
-       (br $switch-default)
+       (br $label$break$L1)
       )
       (set_local $3
        (i32.load
@@ -7159,7 +7159,7 @@
        (get_local $0)
        (i32.const 0)
       )
-      (br $switch-default)
+      (br $label$break$L1)
      )
      (set_local $4
       (f64.load
@@ -7187,7 +7187,7 @@
       (get_local $0)
       (get_local $4)
      )
-     (br $switch-default)
+     (br $label$break$L1)
     )
     (set_local $4
      (f64.load
diff --git a/test/passes/1.txt b/test/passes/1.txt
index 22b7032fe..cf6a569eb 100644
--- a/test/passes/1.txt
+++ b/test/passes/1.txt
@@ -196,12 +196,9 @@
     (i32.const 1)
    )
    (block $switch$3$default
-    (block $switch$3$case$6
-     (br_table $switch$3$case$6 $switch$3$case$6 $switch$3$case$6 $switch$3$default
-      (get_local $0)
-     )
+    (br_table $block$6$break $block$6$break $block$6$break $switch$3$default
+     (get_local $0)
     )
-    (br $block$6$break)
    )
    (call $switch
     (i32.const 2)
diff --git a/test/passes/remove-unused-brs.txt b/test/passes/remove-unused-brs.txt
index 3f4528a5c..a44a62c20 100644
--- a/test/passes/remove-unused-brs.txt
+++ b/test/passes/remove-unused-brs.txt
@@ -1675,6 +1675,7 @@
      )
     )
    )
+   (call $trim-switch)
   )
  )
  (func $same-target-br_if-and-br (; 67 ;) (type $1)
@@ -2129,4 +2130,82 @@
    )
   )
  )
+ (func $switch-to-br (; 97 ;) (type $1)
+  (block $A
+   (block $y
+    (block
+     (drop
+      (i32.const 0)
+     )
+     (br $A)
+    )
+   )
+  )
+ )
+ (func $switch-to-br-value (; 98 ;) (type $2) (result i32)
+  (block $A (result i32)
+   (block $y (result i32)
+    (block
+     (drop
+      (i32.const 1)
+     )
+     (br $A
+      (i32.const 0)
+     )
+    )
+   )
+  )
+ )
+ (func $switch-threading-multi (; 99 ;) (type $3) (param $x i32) (param $y i32) (result i32)
+  (block $block$5$break
+   (block $block$4$break
+    (loop $shape$1$continue
+     (block $block$3$break
+      (block $switch$2$case$5
+       (block $switch$2$case$4
+        (block $switch$2$default
+         (block $switch$2$case$2
+          (br_table $shape$1$continue $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$5$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$3$break $block$4$break $block$3$break
+           (get_local $x)
+          )
+         )
+         (br $shape$1$continue)
+        )
+        (br $block$3$break)
+       )
+       (br $block$4$break)
+      )
+      (br $block$5$break)
+     )
+    )
+    (unreachable)
+   )
+   (set_local $y
+    (i32.const 1)
+   )
+   (unreachable)
+  )
+  (set_local $y
+   (i32.const 2)
+  )
+  (unreachable)
+ )
+ (func $fuzz-type-changes-in-our-cycles (; 100 ;) (type $2) (result i32)
+  (loop $label$1
+   (if
+    (i32.const 0)
+    (if
+     (i32.const 0)
+     (block $label$3
+      (block $block
+      )
+     )
+     (return
+      (i32.const -8192)
+     )
+    )
+   )
+   (br $label$1)
+  )
+ )
 )
diff --git a/test/passes/remove-unused-brs.wast b/test/passes/remove-unused-brs.wast
index ea3e5f320..7a1943c14 100644
--- a/test/passes/remove-unused-brs.wast
+++ b/test/passes/remove-unused-brs.wast
@@ -1355,6 +1355,7 @@
           (i32.const 0)
         )
       )
+      (call $trim-switch)
     )
   )
   (func $same-target-br_if-and-br
@@ -1741,5 +1742,78 @@
     )
    )
   )
+  (func $switch-to-br
+    (block $A
+      (block $y
+        (br_table $y $y $A $A
+          (i32.const 0)
+        )
+      )
+    )
+  )
+  (func $switch-to-br-value (result i32)
+    (block $A (result i32)
+      (block $y (result i32)
+        (br_table $A $A $A
+          (i32.const 0)
+          (i32.const 1)
+        )
+      )
+    )
+  )
+  (func $switch-threading-multi (param $x i32) (param $y i32) (result i32)
+   (block $block$5$break
+    (block $block$4$break
+     (loop $shape$1$continue
+      (block $block$3$break
+       (block $switch$2$case$5
+        (block $switch$2$case$4
+         (block $switch$2$default
+          (block $switch$2$case$2
+           (br_table $switch$2$case$2 $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$case$5 $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$default $switch$2$case$4 $switch$2$default
+            (get_local $x)
+           )
+          )
+          (br $shape$1$continue)
+         )
+         (br $block$3$break)
+        ) ;; switch$2$case$4
+        (br $block$4$break)
+       )
+       (br $block$5$break)
+      )
+     )
+     (unreachable)
+    ) ;; block$4$break
+    (set_local $y
+     (i32.const 1)
+    )
+    (unreachable)
+   )
+   (set_local $y
+    (i32.const 2)
+   )
+   (unreachable)
+  )
+  (func $fuzz-type-changes-in-our-cycles (result i32)
+   (loop $label$1
+    (if
+     (i32.const 0)
+     (block $label$3
+      (if
+       (i32.const 0)
+       (block
+        (nop)
+        (br $label$3)
+       )
+       (return
+        (i32.const -8192)
+       )
+      )
+     )
+    )
+    (br $label$1)
+   )
+  )
 )
 
diff --git a/test/unit.fromasm b/test/unit.fromasm
index 691c65136..3eb75dc5a 100644
--- a/test/unit.fromasm
+++ b/test/unit.fromasm
@@ -182,37 +182,16 @@
     (i32.const 51)
    )
   )
-  (block $switch-case4
-   (drop
-    (i32.add
-     (get_local $0)
-     (i32.const -5)
-    )
-   )
-   (br $switch-case4)
-  )
   (loop $label$continue$L1
    (block $label$break$L1
     (loop $label$continue$L3
      (block $label$break$L3
-      (block $switch-default
-       (block $switch-case13
-        (block $switch-case12
-         (block $switch-case11
-          (br_table $switch-case11 $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-case13 $switch-default $switch-default $switch-default $switch-default $switch-default $switch-case12 $switch-default
-           (i32.sub
-            (get_local $0)
-            (i32.const -1)
-           )
-          )
-         )
-         (br $label$break$L1)
-        )
-        (br $label$continue$L3)
+      (br_table $label$break$L3 $label$break$L1 $label$break$L1 $label$break$L1 $label$break$L1 $label$break$L1 $label$continue$L3 $label$break$L1
+       (i32.add
+        (get_local $0)
+        (i32.const -110)
        )
-       (br $label$break$L3)
       )
-      (br $label$break$L1)
      )
     )
     (call $h
diff --git a/test/unit.fromasm.clamp b/test/unit.fromasm.clamp
index 44de1e100..e34bf66e4 100644
--- a/test/unit.fromasm.clamp
+++ b/test/unit.fromasm.clamp
@@ -232,37 +232,16 @@
     (i32.const 51)
    )
   )
-  (block $switch-case4
-   (drop
-    (i32.add
-     (get_local $0)
-     (i32.const -5)
-    )
-   )
-   (br $switch-case4)
-  )
   (loop $label$continue$L1
    (block $label$break$L1
     (loop $label$continue$L3
      (block $label$break$L3
-      (block $switch-default
-       (block $switch-case13
-        (block $switch-case12
-         (block $switch-case11
-          (br_table $switch-case11 $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-case13 $switch-default $switch-default $switch-default $switch-default $switch-default $switch-case12 $switch-default
-           (i32.sub
-            (get_local $0)
-            (i32.const -1)
-           )
-          )
-         )
-         (br $label$break$L1)
-        )
-        (br $label$continue$L3)
+      (br_table $label$break$L3 $label$break$L1 $label$break$L1 $label$break$L1 $label$break$L1 $label$break$L1 $label$continue$L3 $label$break$L1
+       (i32.add
+        (get_local $0)
+        (i32.const -110)
        )
-       (br $label$break$L3)
       )
-      (br $label$break$L1)
      )
     )
     (call $h
diff --git a/test/unit.fromasm.imprecise b/test/unit.fromasm.imprecise
index d9cd05f28..04794f28f 100644
--- a/test/unit.fromasm.imprecise
+++ b/test/unit.fromasm.imprecise
@@ -178,37 +178,16 @@
     (i32.const 51)
    )
   )
-  (block $switch-case4
-   (drop
-    (i32.add
-     (get_local $0)
-     (i32.const -5)
-    )
-   )
-   (br $switch-case4)
-  )
   (loop $label$continue$L1
    (block $label$break$L1
     (loop $label$continue$L3
      (block $label$break$L3
-      (block $switch-default
-       (block $switch-case13
-        (block $switch-case12
-         (block $switch-case11
-          (br_table $switch-case11 $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-default $switch-case13 $switch-default $switch-default $switch-default $switch-default $switch-default $switch-case12 $switch-default
-           (i32.sub
-            (get_local $0)
-            (i32.const -1)
-           )
-          )
-         )
-         (br $label$break$L1)
-        )
-        (br $label$continue$L3)
+      (br_table $label$break$L3 $label$break$L1 $label$break$L1 $label$break$L1 $label$break$L1 $label$break$L1 $label$continue$L3 $label$break$L1
+       (i32.add
+        (get_local $0)
+        (i32.const -110)
        )
-       (br $label$break$L3)
       )
-      (br $label$break$L1)
      )
     )
     (call $h