blocks must mark as branching in effects analyzer, as control flow can join there if the end of the block was branched to

5 files changed, 45 insertions, 18 deletions

diff --git a/src/ast_utils.h b/src/ast_utils.h
index 190b2876e..bf42d10e1 100644
--- a/src/ast_utils.h
+++ b/src/ast_utils.h
@@ -61,6 +61,7 @@ struct EffectAnalyzer : public WasmWalker<EffectAnalyzer> {
                     || (accessesMemory() && (other.writesMemory || other.calls)) || (accessesLocal() && other.writesLocal);
   }
 
+  void visitBlock(Block *curr) { branches = true; }
   void visitIf(If *curr) { branches = true; }
   void visitBreak(Break *curr) { branches = true; }
   void visitSwitch(Switch *curr) { branches = true; }
diff --git a/test/emcc_hello_world.fromasm b/test/emcc_hello_world.fromasm
index 6c877aa3b..be7a45cec 100644
--- a/test/emcc_hello_world.fromasm
+++ b/test/emcc_hello_world.fromasm
@@ -299,9 +299,9 @@
     )
   )
   (func $_frexp (param $$x f64) (param $$e i32) (result f64)
+    (local $$retval$0 f64)
     (local $$x$addr$0 f64)
     (local $$storemerge i32)
-    (local $$retval$0 f64)
     (local $$1 i32)
     (local $$0 i32)
     (local $$sub8 i32)
@@ -463,19 +463,20 @@
           )
           (get_local $$6)
         )
-      )
-    )
-    (return
-      (set_local $$retval$0
-        (set_local $$7
-          (f64.load
-            (i32.load
-              (i32.const 24)
+        (set_local $$retval$0
+          (set_local $$7
+            (f64.load
+              (i32.load
+                (i32.const 24)
+              )
             )
           )
         )
       )
     )
+    (return
+      (get_local $$retval$0)
+    )
   )
   (func $_frexpl (param $$x f64) (param $$e i32) (result f64)
     (local $sp i32)
diff --git a/test/emcc_hello_world.fromasm.imprecise b/test/emcc_hello_world.fromasm.imprecise
index 343ab13a6..fc4418930 100644
--- a/test/emcc_hello_world.fromasm.imprecise
+++ b/test/emcc_hello_world.fromasm.imprecise
@@ -297,9 +297,9 @@
     )
   )
   (func $_frexp (param $$x f64) (param $$e i32) (result f64)
+    (local $$retval$0 f64)
     (local $$x$addr$0 f64)
     (local $$storemerge i32)
-    (local $$retval$0 f64)
     (local $$1 i32)
     (local $$0 i32)
     (local $$sub8 i32)
@@ -461,19 +461,20 @@
           )
           (get_local $$6)
         )
-      )
-    )
-    (return
-      (set_local $$retval$0
-        (set_local $$7
-          (f64.load
-            (i32.load
-              (i32.const 24)
+        (set_local $$retval$0
+          (set_local $$7
+            (f64.load
+              (i32.load
+                (i32.const 24)
+              )
             )
           )
         )
       )
     )
+    (return
+      (get_local $$retval$0)
+    )
   )
   (func $_frexpl (param $$x f64) (param $$e i32) (result f64)
     (local $sp i32)
diff --git a/test/passes/simplify-locals.txt b/test/passes/simplify-locals.txt
index 477d95250..88c00dbe9 100644
--- a/test/passes/simplify-locals.txt
+++ b/test/passes/simplify-locals.txt
@@ -226,5 +226,19 @@
       (get_local $a)
       (call_import $waka)
     )
+    (block $out-of-block
+      (set_local $a
+        (i32.const 1337)
+      )
+      (block $b
+        (block $c
+          (br $b)
+        )
+        (set_local $a
+          (i32.const 9876)
+        )
+      )
+      (get_local $a)
+    )
   )
 )
diff --git a/test/passes/simplify-locals.wast b/test/passes/simplify-locals.wast
index 6f33db4e2..5b1db2d12 100644
--- a/test/passes/simplify-locals.wast
+++ b/test/passes/simplify-locals.wast
@@ -126,6 +126,16 @@
       (get_local $a) ;; no
       (call_import $waka)
     )
+    (block $out-of-block
+      (set_local $a (i32.const 1337))
+      (block $b
+        (block $c
+          (br $b)
+        )
+        (set_local $a (i32.const 9876))
+      )
+      (get_local $a)
+    )
   )
 )