[Bug middle-end/125621] ICE in build_poly_int_cst with SVE svcntd () and -fsanitize=undefined

[acoplan at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125621

Alex Coplan <acoplan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |acoplan at gcc dot 
gnu.org
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2026-06-05

--- Comment #1 from Alex Coplan <acoplan at gcc dot gnu.org> ---
Testing a fix.

Slightly simpler testcase:

#pragma GCC aarch64 "arm_sve.h"
long foo(long x) {
  return (long)svcntd() * x;
}

(the conversion to long is needed as svcntd () returns uint64_t, and we need a
signed multiplication for ubsan to kick in).