don't create an unnecessary duplicate block in asm2wasm switches, when there isn't a default (#734)

1 files changed, 63 insertions, 71 deletions

diff --git a/test/unit.fromasm.imprecise.no-opts b/test/unit.fromasm.imprecise.no-opts
index bd9f28762..905d13437 100644
--- a/test/unit.fromasm.imprecise.no-opts
+++ b/test/unit.fromasm.imprecise.no-opts
@@ -199,119 +199,111 @@
   (func $switcher (param $x i32) (result i32)
     (local $waka i32)
     (block $switch$0
-      (block $switch-default$3
-        (block $switch-case$2
-          (block $switch-case$1
-            (br_table $switch-case$1 $switch-case$2 $switch-default$3
-              (i32.sub
-                (get_local $x)
-                (i32.const 1)
-              )
+      (block $switch-case$2
+        (block $switch-case$1
+          (br_table $switch-case$1 $switch-case$2 $switch$0
+            (i32.sub
+              (get_local $x)
+              (i32.const 1)
             )
           )
-          (return
-            (i32.const 1)
-          )
         )
         (return
-          (i32.const 2)
+          (i32.const 1)
         )
       )
+      (return
+        (i32.const 2)
+      )
     )
-    (block $switch$4
-      (block $switch-default$7
-        (block $switch-case$6
-          (block $switch-case$5
-            (br_table $switch-case$6 $switch-default$7 $switch-default$7 $switch-default$7 $switch-default$7 $switch-default$7 $switch-default$7 $switch-case$5 $switch-default$7
-              (i32.sub
-                (get_local $x)
-                (i32.const 5)
-              )
+    (block $switch$3
+      (block $switch-case$5
+        (block $switch-case$4
+          (br_table $switch-case$5 $switch$3 $switch$3 $switch$3 $switch$3 $switch$3 $switch$3 $switch-case$4 $switch$3
+            (i32.sub
+              (get_local $x)
+              (i32.const 5)
             )
           )
-          (return
-            (i32.const 121)
-          )
         )
         (return
-          (i32.const 51)
+          (i32.const 121)
         )
       )
+      (return
+        (i32.const 51)
+      )
     )
     (block $label$break$Lout
-      (block $switch-default$16
-        (block $switch-case$15
-          (block $switch-case$12
-            (block $switch-case$9
-              (block $switch-case$8
-                (br_table $switch-case$15 $switch-default$16 $switch-default$16 $switch-case$12 $switch-default$16 $switch-default$16 $switch-default$16 $switch-default$16 $switch-case$9 $switch-default$16 $switch-case$8 $switch-default$16
-                  (i32.sub
-                    (get_local $x)
-                    (i32.const 2)
-                  )
+      (block $switch-case$13
+        (block $switch-case$10
+          (block $switch-case$7
+            (block $switch-case$6
+              (br_table $switch-case$13 $label$break$Lout $label$break$Lout $switch-case$10 $label$break$Lout $label$break$Lout $label$break$Lout $label$break$Lout $switch-case$7 $label$break$Lout $switch-case$6 $label$break$Lout
+                (i32.sub
+                  (get_local $x)
+                  (i32.const 2)
                 )
               )
-              (br $label$break$Lout)
-            )
-            (br $label$break$Lout)
-          )
-          (block
-            (loop $while-in$11
-              (block $while-out$10
-                (br $while-out$10)
-                (br $while-in$11)
-              )
             )
             (br $label$break$Lout)
           )
+          (br $label$break$Lout)
         )
         (block
-          (loop $while-in$14
-            (block $while-out$13
-              (br $label$break$Lout)
-              (br $while-in$14)
+          (loop $while-in$9
+            (block $while-out$8
+              (br $while-out$8)
+              (br $while-in$9)
             )
           )
           (br $label$break$Lout)
         )
       )
+      (block
+        (loop $while-in$12
+          (block $while-out$11
+            (br $label$break$Lout)
+            (br $while-in$12)
+          )
+        )
+        (br $label$break$Lout)
+      )
     )
     (loop $label$continue$L1
       (block $label$break$L1
         (loop $label$continue$L3
           (block $label$break$L3
-            (block $switch$17
-              (block $switch-default$21
-                (block $switch-default$21
-                  (block $switch-case$20
-                    (block $switch-case$19
-                      (block $switch-case$18
-                        (br_table $switch-case$18 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-case$20 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-default$21 $switch-case$19 $switch-default$21
-                          (i32.sub
-                            (get_local $x)
-                            (i32.const -1)
-                          )
+            (block $switch$14
+              (block $switch-default$18
+                (block $switch-case$17
+                  (block $switch-case$16
+                    (block $switch-case$15
+                      (br_table $switch-case$15 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-case$17 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-default$18 $switch-case$16 $switch-default$18
+                        (i32.sub
+                          (get_local $x)
+                          (i32.const -1)
                         )
                       )
-                      (block
-                        (br $label$break$L1)
-                        (br $switch$17)
-                      )
                     )
                     (block
-                      (set_local $waka
-                        (i32.const 1)
-                      )
-                      (br $switch$17)
+                      (br $label$break$L1)
+                      (br $switch$14)
                     )
                   )
                   (block
-                    (br $label$break$L3)
-                    (br $switch$17)
+                    (set_local $waka
+                      (i32.const 1)
+                    )
+                    (br $switch$14)
                   )
                 )
-                (br $label$break$L1)
+                (block
+                  (br $label$break$L3)
+                  (br $switch$14)
+                )
               )
+              (br $label$break$L1)
             )
             (br $label$continue$L3)
           )