Add simple inline macros to js2c and use that for typed array constructors.

Add simple inline macros to js2c and use that for typed array constructors.

R=yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=17491

[Dmitry Lomov (no reviews), 2013-10-25 13:13:43]

PTAL. Adds simple multi-line macros to js2c and generates different functions
for different typed array constructors (to enable optimizing them)

[rossberg, 2013-10-28 10:40:54]

https://codereview.chromium.org/44173003/diff/60001/src/typedarray.js
File src/typedarray.js (right):

https://codereview.chromium.org/44173003/diff/60001/src/typedarray.js#newcode285
src/typedarray.js:285: macro SETUP_TYPED_ARRAY(NAME, ELEMENT_SIZE)
I'd argue that using a macro here is overkill, but if you prefer...

https://codereview.chromium.org/44173003/diff/60001/tools/js2c.py
File tools/js2c.py (right):

https://codereview.chromium.org/44173003/diff/60001/tools/js2c.py#newcode224
tools/js2c.py:224: while True:
Wait, you iterate over the whole file N times, once for each macro? Shouldn't
you first collect the macros, and then expand them simultaneously, like in the
non-inline case? In fact, shouldn't you all expansions together?

https://codereview.chromium.org/44173003/diff/60001/tools/js2c.py#newcode362
tools/js2c.py:362: lines = RemoveCommentsAndTrailingWhitespace(lines)
Why is this needed?

[Dmitry Lomov (no reviews), 2013-11-02 12:56:15]

Replied to your comments

https://codereview.chromium.org/44173003/diff/60001/tools/js2c.py
File tools/js2c.py (right):

https://codereview.chromium.org/44173003/diff/60001/tools/js2c.py#newcode224
tools/js2c.py:224: while True:
On 2013/10/28 10:40:55, rossberg wrote:
> Wait, you iterate over the whole file N times, once for each macro? Shouldn't
> you first collect the macros, and then expand them simultaneously, like in the
> non-inline case? In fact, shouldn't you all expansions together?

Macros in macros + the macro scope is from definition to the end of file. Perf
impact is negligible (note that we iterate the whole file once for each macro in
the "predefined macros" case too).

I am not sure what is your concern here.

https://codereview.chromium.org/44173003/diff/60001/tools/js2c.py#newcode362
tools/js2c.py:362: lines = RemoveCommentsAndTrailingWhitespace(lines)
On 2013/10/28 10:40:55, rossberg wrote:
> Why is this needed?

To handle cases like 
  macro abc(f,g,h) // this is a comment.

[Dmitry Lomov (no reviews), 2013-11-04 09:25:18]

Changing reviewer to Yang since Andreas is on vactaion (Andreas, I am not trying
to avoid your comments! :))

[Dmitry Lomov (no reviews), 2013-11-04 10:19:09]

Made macros in typedarray.js a bit cleverer

[Yang, 2013-11-05 12:41:35]

On 2013/11/04 10:19:09, Dmitry Lomov (chromium) wrote:
> Made macros in typedarray.js a bit cleverer

LGTM, though the fix point iteration is not the most efficient way to do it. But
I guess at this point it doesn't really matter.

[Dmitry Lomov (no reviews), 2013-11-05 13:30:04]

On 2013/11/05 12:41:35, Yang wrote:
> On 2013/11/04 10:19:09, Dmitry Lomov (chromium) wrote:
> > Made macros in typedarray.js a bit cleverer
> 
> LGTM, though the fix point iteration is not the most efficient way to do it.
But
> I guess at this point it doesn't really matter.

As discussed offline, there is no fixpoint iteration here :)

[Dmitry Lomov (no reviews), 2013-11-05 14:08:11]

Committed patchset #4 manually as r17491 (presubmit successful).