[fpc-devel] ppcrossx64 build on macOS darwin with ppca64 is failing

[Karoly Balogh]

Hi,

On Mon, 31 Aug 2026, David Jenkins via fpc-devel wrote:

> I'm trying to build ppcrossx64 on my macOS darwin Tahoe apple silicon machine
> with a ppca64 built from fpc trunk and Xcode 26.6 and no Rosetta running.
>
> Should I expect that to succeed?

Yes. Or at least fail with a meaningful error message, and not with what
you got.

> I am getting the following errors when pp.pas is being compiled:
>
> /Users/djenkins/Source/BCTrunk/Lazarus/fpc/compiler/ppc -Ur -Xs -O2 -n
> -Fux86_64 -Fusystems
> -Fu/Users/djenkins/Source/BCTrunk/Lazarus/fpc/rtl/units/aarch64-darwin
> -Fix86_64 -FEx86_64/bin/aarch64-darwin -FUx86_64/units/aarch64-darwin
> -XR/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -dRELEASE
> -dBC_FPC_BUILD -n @/Users/djenkins/Source/BCTrunk/Lazarus/fpc/../fpc.cfg
> -dlegacysocket -dLIBC_OLDERRNO    -dx86_64 -Fux86 -Fix86 -Sew
> -o/Users/djenkins/Source/BCTrunk/Lazarus/fpc/compiler/ppcrossx64 pp.pas
> <stdin>:5227:9: error: expected compatible register or logical immediate
>         mov     x1,w23
>                    ^
> <stdin>:5241:9: error: expected compatible register or logical immediate
>         mov     x1,w23
>
>
> I did some searching in the gitlab issues and didn't see anything related.
>
> Happy to create a bug report in gitlab if needed.

Please do so. This looks like a genuine bug in the ARM64 codegenerator, I
managed to reproduce it. Without the optimizer enabled (-O- argument), it
actually runs into an internal error 200308299.

Charlie