[Bug target/111733] New: Emit inline SVE FSCALE instruction for ldexp

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111733

            Bug ID: 111733
           Summary: Emit inline SVE FSCALE instruction for ldexp
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
  Target Milestone: ---
            Target: aarch64

Having noticed https://github.com/llvm/llvm-project/pull/67552 in LLVM GCC
should be able to emit the SVE fscale instruction [1] to implement the ldexp
standard function.

There is already an ldexpm3 optab defined so it should be a relatively simple
matter of wiring up the expander for TARGET_SVE

[1]
https://developer.arm.com/documentation/ddi0596/2021-12/SVE-Instructions/FSCALE--Floating-point-adjust-exponent-by-vector--predicated--?lang=en