Arm support for DoubleToIStub (truncating).

Arm support for DoubleToIStub (truncating).

Added support for truncating DoubleToIStub and reorganize the macro-assembler
dToI operations to do the fast-path inline and the slow path by calling the
stub.

BUG=
R=bmeurer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16322

[rmcilroy, 2013-08-14 17:55:19]

I've tried to structure the macro-assembler instructions in a similar way to
oli's patch which you mentioned (https://codereview.chromium.org/22290005/).

Let me know if this is the rough structure you were wanting and, if so, I'll add
Rodolph to the review.

[danno, 2013-08-16 12:18:19]

This is exactly what I envisioned from a high-level and it's pretty close .
Adding Benedikt to do the detailed review.

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
File src/arm/macro-assembler-arm.h (right):

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
src/arm/macro-assembler-arm.h:990: void TryInlineTruncateDoubleToI(Register
result,
Perhaps make this a private member?

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
src/arm/macro-assembler-arm.h:1003: void TruncateDoubleToI(Register result,
Register input, int offset);
Consider calling this TruncateHeapNumberToI like the ia32 version that Oli did
(I don't think that an offset is ever used that's not kPointerSize.

[rmcilroy_google, 2013-08-16 14:43:54]

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
File src/arm/macro-assembler-arm.h (right):

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
src/arm/macro-assembler-arm.h:990: void TryInlineTruncateDoubleToI(Register
result,
On 2013/08/16 12:18:19, danno wrote:
> Perhaps make this a private member?

I did this originally, but then needed to call the method from
test-code-stubs-arm.cc.  I could make a friend class for the test code to call,
but the test isn't currently a class itself.  Any thoughts?

[Benedikt Meurer, 2013-08-19 07:48:01]

Ok, first round of comments.

https://codereview.chromium.org/23129003/diff/11001/src/arm/code-stubs-arm.cc
File src/arm/code-stubs-arm.cc (right):

https://codereview.chromium.org/23129003/diff/11001/src/arm/code-stubs-arm.cc...
src/arm/code-stubs-arm.cc:683: // with exponent because Bias + 1 = 1024 which is
an *ARM* immediate value.
Please add a STATIC_ASSERT() for this.

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
File src/arm/macro-assembler-arm.h (right):

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
src/arm/macro-assembler-arm.h:990: void TryInlineTruncateDoubleToI(Register
result,
On 2013/08/16 14:43:54, rmcilroy_google wrote:
> On 2013/08/16 12:18:19, danno wrote:
> > Perhaps make this a private member?
> 
> I did this originally, but then needed to call the method from
> test-code-stubs-arm.cc.  I could make a friend class for the test code to
call,
> but the test isn't currently a class itself.  Any thoughts?

If there's no easy way to make this private, you should at least add a comment
with reason why this is public.

[rmcilroy, 2013-08-19 12:35:24]

https://codereview.chromium.org/23129003/diff/11001/src/arm/code-stubs-arm.cc
File src/arm/code-stubs-arm.cc (right):

https://codereview.chromium.org/23129003/diff/11001/src/arm/code-stubs-arm.cc...
src/arm/code-stubs-arm.cc:683: // with exponent because Bias + 1 = 1024 which is
an *ARM* immediate value.
On 2013/08/19 07:48:01, Benedikt Meurer wrote:
> Please add a STATIC_ASSERT() for this.

Done.

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
File src/arm/macro-assembler-arm.h (right):

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
src/arm/macro-assembler-arm.h:990: void TryInlineTruncateDoubleToI(Register
result,
On 2013/08/19 07:48:01, Benedikt Meurer wrote:
> On 2013/08/16 14:43:54, rmcilroy_google wrote:
> > On 2013/08/16 12:18:19, danno wrote:
> > > Perhaps make this a private member?
> > 
> > I did this originally, but then needed to call the method from
> > test-code-stubs-arm.cc.  I could make a friend class for the test code to
> call,
> > but the test isn't currently a class itself.  Any thoughts?
> 
> If there's no easy way to make this private, you should at least add a comment
> with reason why this is public.

Done.

https://codereview.chromium.org/23129003/diff/11001/src/arm/macro-assembler-a...
src/arm/macro-assembler-arm.h:1003: void TruncateDoubleToI(Register result,
Register input, int offset);
On 2013/08/16 12:18:19, danno wrote:
> Consider calling this TruncateHeapNumberToI like the ia32 version that Oli did
> (I don't think that an offset is ever used that's not kPointerSize.

Done.

[Benedikt Meurer, 2013-08-20 12:01:16]

lgtm

[Benedikt Meurer, 2013-08-26 12:24:18]

Committed patchset #4 manually as r16322 (presubmit successful).