[aarch64-port-dev ] VAR_CPU_ARCH for ARM platforms

[Andrey Petushkov]

Hi guys,

And indeed, please don't forget about AArch32 port. It's like ARM but it's
quite different, you know. And it is currently using aarch32 value as
VAR_CPU and VAR_CPU_ARCH

Thanks,
Andrey

On Wed, Dec 23, 2015 at 7:56 PM Andrew Haley <aph at redhat.com> wrote:

> On 23/12/15 14:55, Bob Vandette wrote:
>
> > In my push to the mobile/dev forest, I changed VAR_CPU_ARCH on arm
> > platforms to always use arm for both 32 and 64 bit arm builds to be
> > consistent with the setting for x86/x86_64.
>
> This isn't a similar situation, IMO.
>
> > http://cr.openjdk.java.net/~bobv/8145936/webrev.00/ <
> http://cr.openjdk.java.net/~bobv/8145936/webrev.00/>
> >
> > My assumption which is confirmed by most of the usage in the
> > makefiles is that VAR_CPU_ARCH should be set to the generic ARCH
> > family (x86, arm) for both 32 and 64 bit builds.
> >
> > My motivation for doing this was initially for the selection of the
> > Socket and UnixConstant template files used in cross compilation
> > since these files contain the same content for arm and aarch64.
>
> I'm not convinced this makes any sense.  The only thing the ARM
> architectures have in common is that they come from the same company.
> This is not true of x86_64, which is a rather elaborate 64-bit
> extension of x86.  For examples of how the ARM/AArch64 split is
> handled elsewhere, note that the Linux kernel, GCC, and GNU binutils
> arches are all separate.
>
> > There are a lot of hacks in both open and closed makefiles to set
> > various variable based on ARCH in order to end up with the correct
> > variables.
> >
> > In hotspot/make/defs.make, we undo the VAR_CPU_ARCH setting of x86
> > for x86_64 builds by checking for LP64!  This is not done for arm.
>
> It really should not need to be.  AArch64 is not ARM.
>
> Andrew.
>