Simplify HUnaryMathOperation::Canonicalize.

Simplify HUnaryMathOperation::Canonicalize.

Made the logic architecture-independent, although we should really have some kind of instruction selection instead of trying to handle some weird cases at the hydrogen level.

Some tiny related cleanups on the way.

R=bmeurer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=18824

[Benedikt Meurer, 2014-01-23 08:15:12]

As discussed offline: Please don't make hydrogen graph creation platform
dependent, but fix HMathFloorOfDiv instead.

[Benedikt Meurer, 2014-01-24 12:33:21]

https://codereview.chromium.org/141653015/diff/210001/src/arm/lithium-arm.cc
File src/arm/lithium-arm.cc (right):

https://codereview.chromium.org/141653015/diff/210001/src/arm/lithium-arm.cc#...
src/arm/lithium-arm.cc:1304: (right->IsInteger32Constant() &&
right->IsInteger32Constant() is always true here.

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
File src/hydrogen-instructions.cc (right):

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
src/hydrogen-instructions.cc:1459: HValue* left =
SimplifiedDividendForMathFloorOfDiv(hdiv);
Can we please inline the SimplifiedDividend... and SimplifiedDivisor... methods
here? That'd greatly increase readability, since you no longer need to jump
between use and definition to understand what's happening here, and this is the
only call site anyway.

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
File src/hydrogen-instructions.h (right):

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
src/hydrogen-instructions.h:4201: bool HasPowerOf2Divisor() {
This should probably read HasPowerOf2Right() now.

[Sven Panne, 2014-01-24 14:02:05]

Feedback addressed, PTAL again...

https://codereview.chromium.org/141653015/diff/210001/src/arm/lithium-arm.cc
File src/arm/lithium-arm.cc (right):

https://codereview.chromium.org/141653015/diff/210001/src/arm/lithium-arm.cc#...
src/arm/lithium-arm.cc:1304: (right->IsInteger32Constant() &&
On 2014/01/24 12:33:21, Benedikt Meurer wrote:
> right->IsInteger32Constant() is always true here.

Embarrassing... :-} This is what you get after editing the same place 10 times
in a row. :-P Done.

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
File src/hydrogen-instructions.cc (right):

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
src/hydrogen-instructions.cc:1459: HValue* left =
SimplifiedDividendForMathFloorOfDiv(hdiv);
On 2014/01/24 12:33:21, Benedikt Meurer wrote:
> Can we please inline the SimplifiedDividend... and SimplifiedDivisor...
methods
> here? That'd greatly increase readability, since you no longer need to jump
> between use and definition to understand what's happening here, and this is
the
> only call site anyway.

Done.

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
File src/hydrogen-instructions.h (right):

https://codereview.chromium.org/141653015/diff/210001/src/hydrogen-instructio...
src/hydrogen-instructions.h:4201: bool HasPowerOf2Divisor() {
On 2014/01/24 12:33:21, Benedikt Meurer wrote:
> This should probably read HasPowerOf2Right() now.

Good point, but I went for "RightIsPowerOf2". Done.

Perhaps "right()" should be passed as an argument and this function should be
moved elsewhere, but not in this CL.

[Benedikt Meurer, 2014-01-24 14:04:05]

LGTM

[Sven Panne, 2014-01-24 14:05:24]

Committed patchset #9 manually as r18824 (presubmit successful).