Bug 162503 – [Binding] setDOMException should be inlined and fall to the slow path if exception occurs

• Status: RESOLVED
• Resolution: FIXED
• Component: Bindings

[Yusuke Suzuki]

setDOMException is not inlined in binding function.
Since exception rarely occurs, we should inline setDOMException like this.

inline setDOMException()
{
    if (LIKELY(error does not occur))
       return;
    setDOMExceptionSlow();  // never inline.
}

[Yusuke Suzuki]

3794 EncodedJSValue JSC_HOST_CALL jsWebGLRenderingContextBasePrototypeFunctionUniform1f(ExecState* state)
3795 {
3796     VM& vm = state->vm();
3797     auto throwScope = DECLARE_THROW_SCOPE(vm);
3798     UNUSED_PARAM(throwScope);
3799     JSValue thisValue = state->thisValue();
3800     auto castedThis = jsDynamicCast<JSWebGLRenderingContextBase*>(thisValue);
3801     if (UNLIKELY(!castedThis))
3802         return throwThisTypeError(*state, throwScope, "WebGLRenderingContextBase", "uniform1f");
3803     ASSERT_GC_OBJECT_INHERITS(castedThis, JSWebGLRenderingContextBase::info());
3804     auto& impl = castedThis->wrapped();
3805     if (UNLIKELY(state->argumentCount() < 2))
3806         return throwVMError(state, throwScope, createNotEnoughArgumentsError(state));
3807     ExceptionCode ec = 0;
3808     WebGLUniformLocation* location = nullptr;
3809     if (!state->argument(0).isUndefinedOrNull()) {
3810         location = JSWebGLUniformLocation::toWrapped(state->uncheckedArgument(0));
3811         if (UNLIKELY(!location))
3812             return throwArgumentTypeError(*state, throwScope, 0, "location", "WebGLRenderingContextBase", "uniform1f", "WebGLUniformLocation");
3813     }
3814     auto x = convert<float>(*state, state->argument(1), ShouldAllowNonFinite::Yes);
3815     if (UNLIKELY(throwScope.exception()))
3816         return JSValue::encode(jsUndefined());
3817     impl.uniform1f(WTFMove(location), WTFMove(x), ec);
3818     setDOMException(state, ec);
3819     return JSValue::encode(jsUndefined());
3820 }

L3818, in the critical path, setDOMException is called. However, it is rare that an exception is raised. And This function is not inlined currently.

[Yusuke Suzuki]

Created attachment 289724 [details]
Patch

[Yusuke Suzuki]

Created attachment 289725 [details]
Patch

[Yusuke Suzuki]

Created attachment 289729 [details]
Patch

[Saam Barati]

Comment on attachment 289729 [details]
Patch

r=me

[Yusuke Suzuki]

Comment on attachment 289729 [details]
Patch

Thank you!

[WebKit Commit Bot]

Comment on attachment 289729 [details]
Patch

Clearing flags on attachment: 289729

Committed r206354: <http://trac.webkit.org/changeset/206354>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Yusuke Suzuki]

Committed r206360: <http://trac.webkit.org/changeset/206360>