We found that in the spec17 521.wrf program, some loop invariant code generated
from single-precision floating-point approximate division calculation failed to
propose a loop. This is because the pseudo-register that stores the
intermediate temporary calculation results is rewritten in the implementation
of single-precision floating-point approximate division, failing to propose
invariants in the loop2_invariant pass. To this end, the intermediate temporary
calculation results are stored in new pseudo-registers without destroying the
read-write dependency, so that they could be recognized as loop invariants in
the loop2_invariant pass.
After optimization, the number of instructions of 521.wrf is reduced by 0.18%
compared with before optimization (1716612948501 -> 1713471771364).

gcc/ChangeLog:

	* config/loongarch/loongarch.cc (loongarch_emit_swdivsf): Adjust.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/invariant-recip.c: New test.