On 2024-07-18 08:19, Pip Cet wrote:
> It should be mentioned that this isn't just about the CPU: the OS also needs to enable the XMM register set, right?

Right.

In <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58416#c10> GCC's 
Richard Biener suggested a more portable workaround: use -fno-tree-sra 
when generating 32-bit x86 code for which it is not known that SSE2 is 
supported. (With SSE2, -mfpmath=sse is a better workaround.) Using 
-fno-tree-rsa means we needn't worry whether the build and host 
platforms use different CPU types.

I did that by installing the attached patch to Emacs on savannah, and am 
closing the bug report.