optimized switch implementation

test/mjsunit/wasm/asm-wasm.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-wasm
 
 function assertWasm(expected, func, ffi) {
   print("Testing " + func.name + "...");
   assertEquals(expected, Wasm.instantiateModuleFromAsm(
       func.toString(), ffi).caller());
@@ skipping 1475 matching lines @@
       u0xffffffff: u0xffffffff,
       u0x80000000: u0x80000000,
       u0x87654321: u0x87654321,
     };
   }
   var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
   assertEquals(0xffffffff, wasm.u0xffffffff());
   assertEquals(0x80000000, wasm.u0x80000000());
   assertEquals(0x87654321, wasm.u0x87654321());
 })();
+
+(function TestSwitchWithBrTable() {
+  function asmModule() {
+    "use asm";
+    function main(x) {
+      x = x|0;
+      switch(x|0) {
+        case 14: return 14;
+        case 12: return 12;
+        case 15: return 15;
+        case 19: return 19;
+        case 18: return 18;
+        case 16: return 16;
+        default: return -1;
+      }
+      return 0;
+    }
+    return {
+      main: main,
+    };
+  }
+  var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
+  assertEquals(12, wasm.main(12));
+  assertEquals(14, wasm.main(14));
+  assertEquals(15, wasm.main(15));
+  assertEquals(16, wasm.main(16));
+  assertEquals(18, wasm.main(18));
+  assertEquals(19, wasm.main(19));
+  assertEquals(-1, wasm.main(21));
+})();
+
+(function TestSwitchWithBalancedTree() {
+  function asmModule() {
+    "use asm";
+    function main(x) {
+      x = x|0;
+      switch(x|0) {
+        case 5: return 5;
+        case 1: return 1;
+        case 6: return 6;
+        case 9: return 9;
+        case -4: return -4;
+      }
+      return 0;
+    }
+    return {
+      main: main,
+    };
+  }
+  var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
+  assertEquals(-4, wasm.main(-4));
+  assertEquals(1, wasm.main(1));
+  assertEquals(5, wasm.main(5));
+  assertEquals(6, wasm.main(6));
+  assertEquals(9, wasm.main(9));
+  assertEquals(0, wasm.main(11));
+})();
+
+(function TestSwitchHybrid() {
+  function asmModule() {
+    "use asm";
+    function main(x) {
+      x = x|0;
+      switch(x|0) {
+        case 1: return 1;
+        case 2: return 2;
+        case 3: return 3;
+        case 4: return 4;
+        case 7: return 7;
+        case 10: return 10;
+        case 11: return 11;
+        case 12: return 12;
+        case 13: return 13;
+        case 16: return 16;
+        default: return -1;
+      }
+      return 0;
+    }
+    return {
+      main: main,
+    };
+  }
+  var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
+  assertEquals(1, wasm.main(1));
+  assertEquals(2, wasm.main(2));
+  assertEquals(3, wasm.main(3));
+  assertEquals(4, wasm.main(4));
+  assertEquals(7, wasm.main(7));
+  assertEquals(10, wasm.main(10));
+  assertEquals(11, wasm.main(11));
+  assertEquals(12, wasm.main(12));
+  assertEquals(13, wasm.main(13));
+  assertEquals(16, wasm.main(16));
+  assertEquals(-1, wasm.main(20));
+})();
+
+(function TestSwitchWithDefaultOnly() {
+  function asmModule() {
+    "use asm";
+    function main(x) {
+      x = x|0;
+      switch(x|0) {
+        default: return -10;
+      }
+      return 0;
+    }
+    return {
+      main: main,
+    };
+  }
+  var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
+  assertEquals(-10, wasm.main(2));
+  assertEquals(-10, wasm.main(54));
+})();
+
+(function TestEmptySwitch() {
+  function asmModule() {
+    "use asm";
+    function main(x) {
+      x = x|0;
+      switch(x|0) {
+      }
+      return 73;
+    }
+    return {
+      main: main,
+    };
+  }
+  var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
+  assertEquals(73, wasm.main(7));
+})();