Bug 1073652 - Baseline-compile JSOP_THROWING. r=bhackett

js/src/jit-test/tests/ion/throw.js

@@ -94,3 +94,18 @@ for (var i = 0; i < 100; i++) {
     assertEq(getException(test4_4), count-1);
 }
 assertEq(count, 4500);
+
+function test5() {
+    var res = 0;
+    for (var i=0; i<40; i++) {
+	try {
+	    throw i;
+	} catch (e if e % 2) {
+	    res += e;
+	} catch (e) {
+	    res += e * 3;
+	}
+    }
+    return res;
+}
+assertEq(test5(), 1540);

js/src/jit/BaselineCompiler.cpp

@@ -2776,6 +2776,21 @@ BaselineCompiler::emit_JSOP_THROW()
     return callVM(ThrowInfo);
 }
 
+typedef bool (*ThrowingFn)(JSContext *, HandleValue);
+static const VMFunction ThrowingInfo = FunctionInfo<ThrowingFn>(js::ThrowingOperation);
+
+bool
+BaselineCompiler::emit_JSOP_THROWING()
+{
+    // Keep value to throw in R0.
+    frame.popRegsAndSync(1);
+
+    prepareVMCall();
+    pushArg(R0);
+
+    return callVM(ThrowingInfo);
+}
+
 bool
 BaselineCompiler::emit_JSOP_TRY()
 {

js/src/jit/BaselineCompiler.h

@@ -154,6 +154,7 @@ namespace jit {
     _(JSOP_TYPEOFEXPR)         \
     _(JSOP_SETCALL)            \
     _(JSOP_THROW)              \
+    _(JSOP_THROWING)           \
     _(JSOP_TRY)                \
     _(JSOP_FINALLY)            \
     _(JSOP_GOSUB)              \

js/src/vm/Interpreter.cpp

@@ -3290,10 +3290,9 @@ END_CASE(JSOP_FINALLY)
 
 CASE(JSOP_THROWING)
 {
-    JS_ASSERT(!cx->isExceptionPending());
-    Value v;
+    RootedValue &v = rootValue0;
     POP_COPY_TO(v);
-    cx->setPendingException(v);
+    MOZ_ALWAYS_TRUE(ThrowingOperation(cx, v));
 }
 END_CASE(JSOP_THROWING)
 
@@ -3503,6 +3502,17 @@ js::Throw(JSContext *cx, HandleValue v)
     return false;
 }
 
+bool
+js::ThrowingOperation(JSContext *cx, HandleValue v)
+{
+    // Like js::Throw, but returns |true| instead of |false| to continue
+    // execution instead of calling the (JIT) exception handler.
+
+    MOZ_ASSERT(!cx->isExceptionPending());
+    cx->setPendingException(v);
+    return true;
+}
+
 bool
 js::GetProperty(JSContext *cx, HandleValue v, HandlePropertyName name, MutableHandleValue vp)
 {

js/src/vm/Interpreter.h

@@ -366,6 +366,9 @@ class TryNoteIter
 bool
 Throw(JSContext *cx, HandleValue v);
 
+bool
+ThrowingOperation(JSContext *cx, HandleValue v);
+
 bool
 GetProperty(JSContext *cx, HandleValue value, HandlePropertyName name, MutableHandleValue vp);