DCE at the end of wasm2js (#2574)

By doing so we ensure that our calls to convert wasm
types to JS types never try to convert an unreachable.

Fixes #2558

7 files changed, 262 insertions, 69 deletions

diff --git a/test/wasm2js/br.2asm.js b/test/wasm2js/br.2asm.js
index 2a5f6a9ea..d832d45a8 100644
--- a/test/wasm2js/br.2asm.js
+++ b/test/wasm2js/br.2asm.js
@@ -114,10 +114,8 @@ function asmFunc(global, env, buffer) {
  function $13() {
   var $0 = 0, $1_1 = 0, $3_1 = 0;
   block : {
-   loop_in : while (1) {
-    $0 = 3;
-    break block;
-   };
+   $0 = 3;
+   break block;
   }
   return $0 | 0;
  }
@@ -125,11 +123,9 @@ function asmFunc(global, env, buffer) {
  function $14() {
   var $0 = 0, $1_1 = 0, $3_1 = 0;
   block : {
-   loop_in : while (1) {
-    dummy();
-    $0 = 4;
-    break block;
-   };
+   dummy();
+   $0 = 4;
+   break block;
   }
   return $0 | 0;
  }
@@ -137,11 +133,9 @@ function asmFunc(global, env, buffer) {
  function $15() {
   var $0 = 0;
   block : {
-   loop_in : while (1) {
-    dummy();
-    $0 = 5;
-    break block;
-   };
+   dummy();
+   $0 = 5;
+   break block;
   }
   return $0 | 0;
  }
diff --git a/test/wasm2js/br_table.2asm.js b/test/wasm2js/br_table.2asm.js
index 39c89bae7..ad333a0c2 100644
--- a/test/wasm2js/br_table.2asm.js
+++ b/test/wasm2js/br_table.2asm.js
@@ -12568,12 +12568,10 @@ function asmFunc(global, env, buffer) {
  function $20() {
   var $1_1 = 0, $2_1 = 0, $4_1 = 0;
   fake_return_waka123 : {
-   loop_in : while (1) {
-    $1_1 = 3;
-    switch (0 | 0) {
-    default:
-     break fake_return_waka123;
-    };
+   $1_1 = 3;
+   switch (0 | 0) {
+   default:
+    break fake_return_waka123;
    };
   }
   return $1_1 | 0;
@@ -12582,13 +12580,11 @@ function asmFunc(global, env, buffer) {
  function $21() {
   var $1_1 = 0, $2_1 = 0, $4_1 = 0;
   fake_return_waka123 : {
-   loop_in : while (1) {
-    dummy();
-    $1_1 = 4;
-    switch (-1 | 0) {
-    default:
-     break fake_return_waka123;
-    };
+   dummy();
+   $1_1 = 4;
+   switch (-1 | 0) {
+   default:
+    break fake_return_waka123;
    };
   }
   return $1_1 | 0;
@@ -12597,13 +12593,11 @@ function asmFunc(global, env, buffer) {
  function $22() {
   var $1_1 = 0;
   fake_return_waka123 : {
-   loop_in : while (1) {
-    dummy();
-    $1_1 = 5;
-    switch (1 | 0) {
-    default:
-     break fake_return_waka123;
-    };
+   dummy();
+   $1_1 = 5;
+   switch (1 | 0) {
+   default:
+    break fake_return_waka123;
    };
   }
   return $1_1 | 0;
diff --git a/test/wasm2js/br_table_temp.2asm.js b/test/wasm2js/br_table_temp.2asm.js
index 9ac04fdf1..5287d1084 100644
--- a/test/wasm2js/br_table_temp.2asm.js
+++ b/test/wasm2js/br_table_temp.2asm.js
@@ -12564,12 +12564,10 @@ function asmFunc(global, env, buffer) {
  function $20() {
   var $1_1 = 0, $2_1 = 0, $4_1 = 0;
   fake_return_waka123 : {
-   loop_in : while (1) {
-    $1_1 = 3;
-    switch (0 | 0) {
-    default:
-     break fake_return_waka123;
-    };
+   $1_1 = 3;
+   switch (0 | 0) {
+   default:
+    break fake_return_waka123;
    };
   }
   return $1_1 | 0;
@@ -12578,13 +12576,11 @@ function asmFunc(global, env, buffer) {
  function $21() {
   var $1_1 = 0, $2_1 = 0, $4_1 = 0;
   fake_return_waka123 : {
-   loop_in : while (1) {
-    dummy();
-    $1_1 = 4;
-    switch (-1 | 0) {
-    default:
-     break fake_return_waka123;
-    };
+   dummy();
+   $1_1 = 4;
+   switch (-1 | 0) {
+   default:
+    break fake_return_waka123;
    };
   }
   return $1_1 | 0;
@@ -12593,13 +12589,11 @@ function asmFunc(global, env, buffer) {
  function $22() {
   var $1_1 = 0;
   fake_return_waka123 : {
-   loop_in : while (1) {
-    dummy();
-    $1_1 = 5;
-    switch (1 | 0) {
-    default:
-     break fake_return_waka123;
-    };
+   dummy();
+   $1_1 = 5;
+   switch (1 | 0) {
+   default:
+    break fake_return_waka123;
    };
   }
   return $1_1 | 0;
diff --git a/test/wasm2js/excess_fallthrough.2asm.js b/test/wasm2js/excess_fallthrough.2asm.js
index e5c4bcd1a..e8b9352bd 100644
--- a/test/wasm2js/excess_fallthrough.2asm.js
+++ b/test/wasm2js/excess_fallthrough.2asm.js
@@ -26,22 +26,20 @@ function asmFunc(global, env, buffer) {
  
  function foo($0) {
   $0 = $0 | 0;
-  label$4 : while (1) {
-   label$5 : {
-    bar();
-    block : {
-     switch (123 | 0) {
-     case 0:
-      bar();
-      break;
-     default:
-      break label$5;
-     };
-    }
-    return;
+  label$5 : {
+   bar();
+   block : {
+    switch (123 | 0) {
+    case 0:
+     bar();
+     break;
+    default:
+     break label$5;
+    };
    }
-   abort();
-  };
+   return;
+  }
+  abort();
  }
  
  var FUNCTION_TABLE = [];
diff --git a/test/wasm2js/unreachable-later.2asm.js b/test/wasm2js/unreachable-later.2asm.js
new file mode 100644
index 000000000..f818fb7b1
--- /dev/null
+++ b/test/wasm2js/unreachable-later.2asm.js
@@ -0,0 +1,77 @@
+
+function asmFunc(global, env, buffer) {
+ var HEAP8 = new global.Int8Array(buffer);
+ var HEAP16 = new global.Int16Array(buffer);
+ var HEAP32 = new global.Int32Array(buffer);
+ var HEAPU8 = new global.Uint8Array(buffer);
+ var HEAPU16 = new global.Uint16Array(buffer);
+ var HEAPU32 = new global.Uint32Array(buffer);
+ var HEAPF32 = new global.Float32Array(buffer);
+ var HEAPF64 = new global.Float64Array(buffer);
+ var Math_imul = global.Math.imul;
+ var Math_fround = global.Math.fround;
+ var Math_abs = global.Math.abs;
+ var Math_clz32 = global.Math.clz32;
+ var Math_min = global.Math.min;
+ var Math_max = global.Math.max;
+ var Math_floor = global.Math.floor;
+ var Math_ceil = global.Math.ceil;
+ var Math_sqrt = global.Math.sqrt;
+ var abort = env.abort;
+ var nan = global.NaN;
+ var infinity = global.Infinity;
+ var global$0 = 10;
+ function $0($0_1) {
+  $0_1 = $0_1 | 0;
+  var $15 = Math_fround(0), $21 = 0, $29 = 0, $26 = 0;
+  if (global$0) {
+   return $0_1 | 0
+  }
+  if (global$0) {
+   return $0_1 | 0
+  }
+  global$0 = 0;
+  label$3 : while (1) {
+   label$4 : {
+    if (global$0) {
+     return $0_1 | 0
+    }
+    if (global$0) {
+     return $0_1 | 0
+    }
+    if (global$0) {
+     return $0_1 | 0
+    }
+    $15 = Math_fround(0.0);
+    if (global$0) {
+     return $0_1 | 0
+    }
+   }
+   $21 = 32;
+   if (!$21) {
+    continue label$3
+   }
+   $26 = 1;
+   break label$3;
+  };
+  if (!$26) {
+   $29 = 0
+  } else {
+   $29 = 1
+  }
+  if (!$29) {
+   return -255 | 0
+  } else {
+   abort()
+  }
+ }
+ 
+ var FUNCTION_TABLE = [];
+ return {
+  "func_50": $0
+ };
+}
+
+var memasmFunc = new ArrayBuffer(65536);
+var retasmFunc = asmFunc({Math,Int8Array,Uint8Array,Int16Array,Uint16Array,Int32Array,Uint32Array,Float32Array,Float64Array,NaN,Infinity}, {abort:function() { throw new Error('abort'); }},memasmFunc);
+export var func_50 = retasmFunc.func_50;
diff --git a/test/wasm2js/unreachable-later.2asm.js.opt b/test/wasm2js/unreachable-later.2asm.js.opt
new file mode 100644
index 000000000..b0006309f
--- /dev/null
+++ b/test/wasm2js/unreachable-later.2asm.js.opt
@@ -0,0 +1,50 @@
+
+function asmFunc(global, env, buffer) {
+ var HEAP8 = new global.Int8Array(buffer);
+ var HEAP16 = new global.Int16Array(buffer);
+ var HEAP32 = new global.Int32Array(buffer);
+ var HEAPU8 = new global.Uint8Array(buffer);
+ var HEAPU16 = new global.Uint16Array(buffer);
+ var HEAPU32 = new global.Uint32Array(buffer);
+ var HEAPF32 = new global.Float32Array(buffer);
+ var HEAPF64 = new global.Float64Array(buffer);
+ var Math_imul = global.Math.imul;
+ var Math_fround = global.Math.fround;
+ var Math_abs = global.Math.abs;
+ var Math_clz32 = global.Math.clz32;
+ var Math_min = global.Math.min;
+ var Math_max = global.Math.max;
+ var Math_floor = global.Math.floor;
+ var Math_ceil = global.Math.ceil;
+ var Math_sqrt = global.Math.sqrt;
+ var abort = env.abort;
+ var nan = global.NaN;
+ var infinity = global.Infinity;
+ var global$0 = 10;
+ function $0($0_1) {
+  $0_1 = $0_1 | 0;
+  folding_inner0 : {
+   if (global$0) {
+    break folding_inner0
+   }
+   global$0 = 0;
+   if (global$0) {
+    break folding_inner0
+   }
+   if (global$0) {
+    break folding_inner0
+   }
+   abort();
+  }
+  return $0_1 | 0;
+ }
+ 
+ var FUNCTION_TABLE = [];
+ return {
+  "func_50": $0
+ };
+}
+
+var memasmFunc = new ArrayBuffer(65536);
+var retasmFunc = asmFunc({Math,Int8Array,Uint8Array,Int16Array,Uint16Array,Int32Array,Uint32Array,Float32Array,Float64Array,NaN,Infinity}, {abort:function() { throw new Error('abort'); }},memasmFunc);
+export var func_50 = retasmFunc.func_50;
diff --git a/test/wasm2js/unreachable-later.wast b/test/wasm2js/unreachable-later.wast
new file mode 100644
index 000000000..0af552212
--- /dev/null
+++ b/test/wasm2js/unreachable-later.wast
@@ -0,0 +1,86 @@
+(module
+ (type $0 (func (param i32) (result i32)))
+ (global $global$0 (mut i32) (i32.const 10))
+ (export "func_50" (func $0))
+ (func $0 (; 0 ;) (type $0) (param $0 i32) (result i32)
+  (if
+   (global.get $global$0)
+   (return
+    (local.get $0)
+   )
+  )
+  (if
+   (global.get $global$0)
+   (return
+    (local.get $0)
+   )
+  )
+  (global.set $global$0
+   (i32.const 0)
+  )
+  (if
+   (i32.eqz
+    (if (result i32)
+     (i32.eqz
+      (loop $label$3 (result i32)
+       (br_if $label$3
+        (i32.eqz
+         (if (result i32)
+          (block $label$4 (result i32)
+           (if
+            (global.get $global$0)
+            (return
+             (local.get $0)
+            )
+           )
+           (drop
+            (if (result f32)
+             (block $label$6 (result i32)
+              (if
+               (global.get $global$0)
+               (return
+                (local.get $0)
+               )
+              )
+              (i32.const 65445)
+             )
+             (block (result f32)
+              (if
+               (global.get $global$0)
+               (return
+                (local.get $0)
+               )
+              )
+              (f32.const 0)
+             )
+             (f32.const 1)
+            )
+           )
+           (if
+            (global.get $global$0)
+            (return
+             (local.get $0)
+            )
+           )
+           (i32.const 1)
+          )
+          (i32.const 32)
+          (i32.const 0)
+         )
+        )
+       )
+       (i32.const 1)
+      )
+     )
+     (i32.const 0)
+     (i32.const 1)
+    )
+   )
+   (return
+    (i32.const -255)
+   )
+   (unreachable)
+  )
+ )
+)
+