PPC32 port guidance

[rc-matthew-l-weber]

Before I get started I figured I should ask around about current state.

For this port, I'm targetting the PowerPC ISA v.2.03 using the Book III-E specification. (Freescale PowerPC e200/e500 and IBM PowerPC 405/440/460/970/Power5/Power6)

I have looked a little bit at the different changes IBM has done over the years and still need to evaluate if their fork already has this support. (https://stackoverflow.com/questions/18519899/is-it-possible-to-run-nodejs-on-powerpc-based-linux)

Is there a "zero", emulation or non-native mode that I could use instead of adding another processor ISA support?

[richardlau]

The IBM fork of Node.js for PPC was merged into this repository years ago (around Node.js 4) but only 64-bit was supported. IBM did build 32-bit PPC binaries for a while but I don't think we supported Power5 and we definitely had reports that the fork didn't work on e500 (ibmruntimes/node#67).

cc @nodejs/platform-ppc

[rc-matthew-l-weber]

I'm doing a cross-build (Buildroot build for e200 target so I assume simulation is on) and currently stuck on

error: static assertion failed: FIELD_SIZE(kOptionalPaddingOffset) == kHeaderPaddingSize)

Just trying to get far enough to start working the other asm related build failures I'd expect based on the other tickets.

[bnoordhuis]

If you're targeting a 32-bits system then you probably need this in deps/v8/src/objects/code.h:

#elif V8_TARGET_ARCH_PPC32  // or whatever it's called
  static constexpr int kHeaderPaddingSize =
      FLAG_enable_embedded_constant_pool ? 24 : 0;
#else
  // ...

[rc-matthew-l-weber]

@bnoordhuis thanks for that. I still see to get the following error. I'll keep looking at my build configuration and see if some initial flag isn't getting set. My cross toolchain is attempting to build for a e200 system. I'm not doing a native build of nodejs, maybe that's the issue?

https://pastebin.com/eZd774C1

[Menotdan]

@rc-matthew-l-weber do you configure with - -target-cpu=ppc?
I think that's the flag
Also I'm pretty sure the PPC flag is V8_TARGET_ARCH_PPC (no 32)

[Menotdan]

Also does anyone here know if it's ok to remove the some of the STATIC_ASSERT calls?
I'm having problems with kSmi tagging and stuff like that.

(I'm building my own version for PPC natively on my PowerBook G4 1.67ghz 15")

[Menotdan]

I removed some of the STATIC_ASSERT calls and now I'm having an error because of the missing information for the jump tables on PPC

@bnoordhuis Do you know what the values for the jump tables on PPC are?

[rc-matthew-l-weber]

@rc-matthew-l-weber do you configure with - -target-cpu=ppc?

./configure --prefix=/usr --dest-cpu=ppc --without-snapshot --shared-zlib --shared-cares --shared-libuv --without-dtrace --without-etw --cross-compiling --shared-nghttp2 --dest-os=linux --without-ssl --with-intl=none --without-npm

[bnoordhuis]

Also does anyone here know if it's ok to remove the some of the STATIC_ASSERT calls?

That's unlikely to end well. :-)

What jump tables are you referring to? There are quite a few places in V8 where it generates them.

[Menotdan]

The part where it needs data that is Arch dependent, I think it was the jump size table

[bnoordhuis]

This issue has been inactive for over 8 months. I'll go ahead and close it.