Re: [PATCH] powerpc: e500: Fix compilation with gcc e500 compiler
From: Segher Boessenkool <hidden>
Date: 2022-05-24 18:58:16
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On Tue, May 24, 2022 at 08:12:55PM +0200, Pali Rohár wrote:
On Tuesday 24 May 2022 12:59:55 Segher Boessenkool wrote:quoted
On Tue, May 24, 2022 at 11:39:39AM +0200, Pali Rohár wrote:quoted
gcc e500 compiler does not support -mcpu=powerpc option. When it is specified then gcc throws compile error: gcc: error: unrecognized argument in option ‘-mcpu=powerpc’ gcc: note: valid arguments to ‘-mcpu=’ are: 8540 8548 nativeWhat? Are you using some modified version of GCC, perhaps?Hello! I'm using official gcc version, no special modification.quoted
No version of GCC that isn't hamstrung can have this output.gcc for e500 cores has really this output when you pass -mcpu=powerpc. Upstream gcc dropped support for e500 cores during development of version 9.
This isn't true. The SPE instruction extension is no longer supported (because it wasn't maintained). Everything else still works.
But you can still compile and install gcc 8.5.0 (last version of gcc 8) which has this full e500 support. Really, you can easily try it. Debian 10 (Buster) has gcc 8.3.0 in its default installation and also provides packages with cross compilers. Just run 'sudo apt install gcc-powerpc-linux-gnuspe' on desktop amd64 version of Debian 10, it will install e500 cross compiler. -mcpu=8540 specify e500v1 and -mcpu=8548 specify e500v2
Aha. Right, because this config forces -mspe it requires one of these CPUs. You can use a powerpc-linux compiler instead, and everything will just work. These CPUs are still supported, in all of GCC 9 .. GCC 12 :-) Segher