ARM: Makefile/gyp update allowing better control of ARM specific options.

ARM: Makefile/gyp update allowing better control of ARM specific options.

This patch defines new makefile command line paramaters to better control the
ARM specific options. The new paramters are
 * armfpu      = vfp, vfpv3-d16, vfpv3, neon.
 * armfloatabi = softfp, hard
 * armneon     = on
 * armthumb    = on, off
 * armtest     = on
One existing paratemer has been modified:
 * armv7       = true, false
A number of parameters have been deprecated (but are still working):
 * hardfp      = on, off
 * vfp2        = off
 * vfp3        = off

the armtest paratmer when set to "on" will lock the options used during compile
time at runtime. This allows for example to easily test the ARMv6 build on an
ARMv7 platform without having to worry about features detected at runtime. When
not specified the compiler default will be used meaning it is not necessary
anymore to specify hardfp=on when natively building on an hardfp platform.

The shell help now prints the target options and features detected.

BUG=none
TEST=none

Committed: https://code.google.com/p/v8/source/detail?r=14288

[ulan, 2013-04-16 10:12:18]

I like this change! Adding Jakob in case I missed something in gyp files.

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:115: PrintFeatures();
Debug print?

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:213: #  if defined CAN_USE_ARMV7_INSTRUCTIONS
Shouldn't it be CAN_USE_VFP3_INSTRUCTIONS?

https://codereview.chromium.org/14263018/diff/1/src/arm/constants-arm.h
File src/arm/constants-arm.h (right):

https://codereview.chromium.org/14263018/diff/1/src/arm/constants-arm.h#newco...
src/arm/constants-arm.h:47: # define CAN_USE_VFP3_INSTRUCTIONS
Does __ARM_ARCH_7__ imply VFP3?

[Rodolph Perfetta, 2013-04-16 10:49:35]

Let me know what you think about debug print and snapshots (see my reply to your
comment) and I'll upload a new patch.

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:115: PrintFeatures();
On 2013/04/16 10:12:18, ulan wrote:
> Debug print?

I find it useful to see these info printed when I do a release build too. I am
fine with printing it only in debug mode though, let me know what you prefer.

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:213: #  if defined CAN_USE_ARMV7_INSTRUCTIONS
On 2013/04/16 10:12:18, ulan wrote:
> Shouldn't it be CAN_USE_VFP3_INSTRUCTIONS?

Done.

https://codereview.chromium.org/14263018/diff/1/src/arm/constants-arm.h
File src/arm/constants-arm.h (right):

https://codereview.chromium.org/14263018/diff/1/src/arm/constants-arm.h#newco...
src/arm/constants-arm.h:47: # define CAN_USE_VFP3_INSTRUCTIONS
On 2013/04/16 10:12:18, ulan wrote:
> Does __ARM_ARCH_7__ imply VFP3?

Here yes, V8 requires VFP support and VFP + ARMv7 imply VFPv3

[Jakob Kummerow, 2013-04-16 11:36:07]

Build system stuff LGTM, with a suggestion.

https://codereview.chromium.org/14263018/diff/1/build/common.gypi
File build/common.gypi (right):

https://codereview.chromium.org/14263018/diff/1/build/common.gypi#newcode155
build/common.gypi:155: 'target_conditions': [
Refactoring suggestion (feel free to ignore if you think it wouldn't be better,
or if it's not possible for some reason I'm overlooking):
It seems all these conditional settings (up to and excluding ARM_TEST) apply to
the target toolset only. You could pull up the _toolset=="target"
target_condition to wrap everything, that would avoid spelling it out over and
over again.

[Rodolph Perfetta, 2013-04-16 14:15:55]

Ulan, let me know how you feel about printing features when generating
snapshots.

https://codereview.chromium.org/14263018/diff/1/build/common.gypi
File build/common.gypi (right):

https://codereview.chromium.org/14263018/diff/1/build/common.gypi#newcode155
build/common.gypi:155: 'target_conditions': [
On 2013/04/16 11:36:08, Jakob wrote:
> Refactoring suggestion (feel free to ignore if you think it wouldn't be
better,
> or if it's not possible for some reason I'm overlooking):
> It seems all these conditional settings (up to and excluding ARM_TEST) apply
to
> the target toolset only. You could pull up the _toolset=="target"
> target_condition to wrap everything, that would avoid spelling it out over and
> over again.

Done.

[ulan, 2013-04-16 14:20:50]

LGTM

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/14263018/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:115: PrintFeatures();
On 2013/04/16 10:49:35, Rodolph Perfetta wrote:
> On 2013/04/16 10:12:18, ulan wrote:
> > Debug print?
> 
> I find it useful to see these info printed when I do a release build too. I am
> fine with printing it only in debug mode though, let me know what you prefer.
> 

I see. I don't mind printing it.