> On 24 Feb 2016, at 11:58, Michael du Breuil <wicked.shell.scri...@gmail.com> > wrote: > > That just performs a runtime cast to a variable then reference the variable > later, which is even worse. > > float x = RT.uncheckedFloatCast(-199L);((SpriteBatch)batch) > > .draw((TextureRegion)((IFn)const__5.getRawRoot()).invoke(const__42.getRawRoot()), > x, > > RT.uncheckedFloatCast(-32L)); >
No it doesn't.
having
(ns test)
(definterface Foo
(x [^float y]))
(let [a (float 1)]
(defn y [b]
(.x ^Foo b a)))
This is the disassemble of y's invoke method:
public java.lang.Object invoke(java.lang.Object);
Code:
0: aload_1
1: aconst_null
2: astore_1
3: checkcast #18 // class test/Foo
6: aload_0
7: getfield #14 // Field a:F
10: invokeinterface #22, 2 // InterfaceMethod
test/Foo.x:(F)Ljava/lang/Object;
15: areturn
No float cast involved there. The primitive float is closed over and used
directly.
> I definitely expected the compiler to pay attention to it, although I also
> discovered at the same time that the compilier doesn't actually resolve
> expressions like (+ (* 2 4) 1) to just be 9 at compile time either, even
> though all the values were constants. Both of these are a problem because
> they are inside the hot loop of the program. (There are some constant math
> expressions that are only expressions as it is easier to read/change ^:const
> named things then to just put one resultant number.
>
> Is it worth opening a Jira issue for resolving either or both of these at
> compile time? I looked a briefly at the definition for (float ) but I'm not
> at all familiar with how the byte code is generated and how to actually
> replace that with what I'm looking for.
Sure, although I don't think doing this kind of constant folding this is going
to be a priority.
>
> On Wednesday, February 24, 2016 at 3:58:46 AM UTC-7, Nicola Mometto wrote:
> Those are runtime casts, this is the expected behaviour (although one could
> argue that clojure should be able to optimize them away at compile time).
>
> If you want to avoid the runtime casting, you can do something like this:
>
> (let [x (float 123)]
> (defn y [..]
> (.foo bar x)))
>
>
> > On 24 Feb 2016, at 10:53, Michael du Breuil <wicked.she...@gmail.com> wrote:
> >
> > The following (this is interop with libgdx if anyone is curious,
> > hud-corner-top-left is a delayed TextureRegion
> >
> > (.draw batch ^TextureRegion @hud-corner-top-left
> > (float -199)
> > (float -32))
> >
> > Which yields the following:
> >
> > .draw((TextureRegion)((IFn)const__5.getRawRoot()).invoke(const__41.getRawRoot()),
> > RT.uncheckedFloatCast(-199L),
> > RT.uncheckedFloatCast(-32L));null;((SpriteBatch)batch)
> >
> > Unless I'm missing something on how to interpret bytecode :) I can post
> > more source if you want but that is one interop call and its generated
> > code, the rest will look the same.
> >
> > On Wednesday, February 24, 2016 at 3:44:11 AM UTC-7, Nicola Mometto wrote:
> > Can you post the code?
> >
> > > On 24 Feb 2016, at 10:26, Michael du Breuil <wicked.she...@gmail.com>
> > > wrote:
> > >
> > > I have some interop code that I have carefully specified all the
> > > arguments to be in the correct type (IE the function signature takes 3
> > > floats, so I cast everything to float so that I can avoid reflection).
> > > What I'm surprised by is compile time constants such as (float -173) or
> > > (float 8.5) are not saved as the correct primitive type, using jd-gui I
> > > see that these were actually turned into RT.uncheckedFloatCast(-173L),
> > > and RT.uncheckedFloatCast(8.5D), respectively. Why isn't this just saved
> > > as a the correct primitive directly in the generated bytecode? This is
> > > with clojure 1.8.0
> > >
> > > --
> > > You received this message because you are subscribed to the Google
> > > Groups "Clojure" group.
> > > To post to this group, send email to clo...@googlegroups.com
> > > Note that posts from new members are moderated - please be patient with
> > > your first post.
> > > To unsubscribe from this group, send email to
> > > clojure+u...@googlegroups.com
> > > For more options, visit this group at
> > > http://groups.google.com/group/clojure?hl=en
> > > ---
> > > You received this message because you are subscribed to the Google Groups
> > > "Clojure" group.
> > > To unsubscribe from this group and stop receiving emails from it, send an
> > > email to clojure+u...@googlegroups.com.
> > > For more options, visit https://groups.google.com/d/optout.
> >
> >
> > --
> > You received this message because you are subscribed to the Google
> > Groups "Clojure" group.
> > To post to this group, send email to clo...@googlegroups.com
> > Note that posts from new members are moderated - please be patient with
> > your first post.
> > To unsubscribe from this group, send email to
> > clojure+u...@googlegroups.com
> > For more options, visit this group at
> > http://groups.google.com/group/clojure?hl=en
> > ---
> > You received this message because you are subscribed to the Google Groups
> > "Clojure" group.
> > To unsubscribe from this group and stop receiving emails from it, send an
> > email to clojure+u...@googlegroups.com.
> > For more options, visit https://groups.google.com/d/optout.
>
>
> --
> You received this message because you are subscribed to the Google
> Groups "Clojure" group.
> To post to this group, send email to clojure@googlegroups.com
> Note that posts from new members are moderated - please be patient with your
> first post.
> To unsubscribe from this group, send email to
> clojure+unsubscr...@googlegroups.com
> For more options, visit this group at
> http://groups.google.com/group/clojure?hl=en
> ---
> You received this message because you are subscribed to the Google Groups
> "Clojure" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to clojure+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
---
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
signature.asc
Description: Message signed with OpenPGP using GPGMail
