Files
clang-p2996/llvm/test/CodeGen/ARM
Sergei Barannikov 8c56dd3040 [ARM] Stop gluing FP comparisons to FMSTAT (#116676)
Following #116547, this changes the result of `ARMISD::CMPFP*` and the
operand of `ARMISD::FMSTAT` from a special `Glue` type to a normal type.

This change allows comparisons to be CSEd and scheduled around as can be
seen in the test changes.

Note that `ARMISD::FMSTAT` is still glued to its consumer nodes; this is
going to be changed in a separate patch.

This patch also sets `CopyCost` of `cl_FPSCR_NZCV` register class to a
negative value. The reason is the same as for CCR register class: it
makes DAG scheduler and InstrEmitter try to avoid copies of `FPCSR_NZCV`
register to / from virtual registers. Previously, this was not
necessary, since no attempt was made to create copies in the first
place.

There might be a case when a copy can't be avoided (although not found
in existing tests). If a copy is necessary, the virtual register will be
created with `cl_FPSCR_NZCV` register class. If this register class is
inappropriate, `TRI::getCrossCopyRegClass` should be modified to return
the correct class.

Pull Request: https://github.com/llvm/llvm-project/pull/116676
2024-11-20 16:07:05 +03:00
..
2024-05-14 16:36:39 +01:00