[Bug libstdc++/114417] New: simd parameters are passed by memory on x64 , not using the available sse registers

[lee.imple at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114417

            Bug ID: 114417
           Summary: simd parameters are passed by memory on x64 , not
                    using the available sse registers
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lee.imple at gmail dot com
  Target Milestone: ---

https://godbolt.org/z/3GYnadqc1

In current implementation, SIMD parameters are passed by memory, while the
equivalent vector parameters are passed by SSE registers. If the equivalent
vector parameters can be passed by SSE registers, can we use SSE registers for
SIMD parameters?

Maybe the performance difference is not so significant, but I just want to keep
everything in registers.