Hi Ulrich. I just checked my copy of s390.md and I don’t see LA being used for arithmetic.
If your copy of s390.md is using LA for arithmetic then would it be possible to have an option to use a normal mathematics instruction instead of LA? Do you have any more examples besides LA being used for maths instead of a proper maths instruction? Also, I just realized – if GCC is using LA for maths for 32-bit registers, then values will be limited to 2 GiB instead of 4 GiB for unsigned, but that is not the case. BFN. Paul. From: Ulrich Weigand Sent: Friday, September 3, 2021 12:53 AM To: Paul Edwards Cc: gcc@gcc.gnu.org ; Ulrich Weigand Subject: Re: s390 port "Paul Edwards" <mutazi...@gmail.com> wrote on 02.09.2021 16:50:35: > Could you give me an example of an instruction > generated by –m31 that is not expected to work > on an AM64 system? Well, everything related to address computation, of course. For example, GCC may use LA on -m31 to implement a 31-bit addition, while it may use LA on -m64 to implement a 64-bit addition. Bye, Ulrich
