Add for loop to asm-to-wasm

TEST=asm-wasm.js
R=titzer@chromium.org,bradnelson@google.com
BUG=

Review URL: https://codereview.chromium.org/1523843003

Cr-Commit-Position: refs/heads/master@{#32895}

src/wasm/asm-wasm-builder.cc

@@ -226,16 +226,39 @@ class AsmWasmBuilderImpl : public AstVisitor {
   }
 
   void VisitForStatement(ForStatement* stmt) {
+    DCHECK(in_function_);
     if (stmt->init() != NULL) {
+      block_size_++;
       RECURSE(Visit(stmt->init()));
     }
+    current_function_builder_->Emit(kExprLoop);
+    uint32_t index = current_function_builder_->EmitEditableImmediate(0);
+    int prev_block_size = block_size_;
+    block_size_ = 0;
+    breakable_blocks_.push_back(
+        std::make_pair(stmt->AsBreakableStatement(), true));
     if (stmt->cond() != NULL) {
+      block_size_++;
+      current_function_builder_->Emit(kExprIf);
+      current_function_builder_->Emit(kExprBoolNot);
       RECURSE(Visit(stmt->cond()));
+      current_function_builder_->EmitWithU8(kExprBr, 1);
+      current_function_builder_->Emit(kExprNop);
+    }
+    if (stmt->body() != NULL) {
+      block_size_++;
+      RECURSE(Visit(stmt->body()));
     }
     if (stmt->next() != NULL) {
+      block_size_++;
       RECURSE(Visit(stmt->next()));
     }
-    RECURSE(Visit(stmt->body()));
+    block_size_++;
+    current_function_builder_->EmitWithU8(kExprBr, 0);
+    current_function_builder_->Emit(kExprNop);
+    current_function_builder_->EditImmediate(index, block_size_);
+    block_size_ = prev_block_size;
+    breakable_blocks_.pop_back();
   }
 
   void VisitForInStatement(ForInStatement* stmt) {

test/mjsunit/wasm/asm-wasm.js

@@ -551,3 +551,88 @@ function TestGlobalsWithInit() {
 var module = WASM.instantiateModuleFromAsm(TestGlobalsWithInit.toString());
 module.__init__();
 assertEquals(77.5, module.add());
+
+function TestForLoop() {
+  "use asm"
+
+  function caller() {
+    var ret = 0;
+    var i = 0;
+    for (i = 2; i <= 10; i = (i+1)|0) {
+      ret = (ret + i) | 0;
+    }
+    return ret|0;
+  }
+
+  return {caller:caller};
+}
+
+assertEquals(54, WASM.asmCompileRun(TestForLoop.toString()));
+
+function TestForLoopWithoutInit() {
+  "use asm"
+
+  function caller() {
+    var ret = 0;
+    var i = 0;
+    for (; i < 10; i = (i+1)|0) {
+      ret = (ret + 10) | 0;
+    }
+    return ret|0;
+  }
+
+  return {caller:caller};
+}
+
+assertEquals(100, WASM.asmCompileRun(TestForLoopWithoutInit.toString()));
+
+function TestForLoopWithoutCondition() {
+  "use asm"
+
+  function caller() {
+    var ret = 0;
+    var i = 0;
+    for (i=1;; i = (i+1)|0) {
+      ret = (ret + i) | 0;
+      if (i == 11) {
+        break;
+      }
+    }
+    return ret|0;
+  }
+
+  return {caller:caller};
+}
+
+assertEquals(66, WASM.asmCompileRun(TestForLoopWithoutCondition.toString()));
+
+function TestForLoopWithoutNext() {
+  "use asm"
+
+  function caller() {
+    var i = 0;
+    for (i=1; i < 41;) {
+      i = (i + 1) | 0;
+    }
+    return i|0;
+  }
+
+  return {caller:caller};
+}
+
+assertEquals(41, WASM.asmCompileRun(TestForLoopWithoutNext.toString()));
+
+function TestForLoopWithoutBody() {
+  "use asm"
+
+  function caller() {
+    var i = 0;
+    for (i=1; i < 45 ; i = (i+1)|0) {
+    }
+    return i|0;
+  }
+
+  return {caller:caller};
+}
+
+assertEquals(45, WASM.asmCompileRun(TestForLoopWithoutBody.toString()));