Errors like the following are reported by:
https://urldefense.proofpoint.com/v2/url?u=http-3A__lab.llvm.org-3A8011_builders_llvm-2Dclang-2Dx86-5F64-2Dexpensive-2Dchecks-2Dwin_builds_11261&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=929oWPCf7Bf2qQnir4GBtowB8ZAlIRWsAdTfRkDaK-g&s=9k-wbEUVpUm474hhzsmAO29VXVvbxJPWD9RTgCD71fQ&e=
*** Bad machine code: Explicit definition marked as use ***
- function: cal_align1
- basic block: %bb.0 entry (0x47edd98)
- instruction: LDB $r3, $r2, 0
- operand 0: $r3
This is because RegState info was missing for ScratchReg inside
expandMEMCPY. This caused incomplete register usage information to
MachineInstr verifier which then would complain as there could be potential
code-gen issue if the complained MachineInstr is used in place where
register usage information matters even though the memcpy expanding is not
in such case as it happens at the last stage of IR optimization pipeline.
We should always specify those register usage information which compiler
couldn't deduct automatically whenever we add a hardware register manually.
Reported-by: Builder llvm-clang-x86_64-expensive-checks-win Build #11261
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 338134
Some BPF JIT backends would want to optimize memcpy in their own
architecture specific way.
However, at the moment, there is no way for JIT backends to see memcpy
semantics in a reliable way. This is due to LLVM BPF backend is expanding
memcpy into load/store sequences and could possibly schedule them apart from
each other further. So, BPF JIT backends inside kernel can't reliably
recognize memcpy semantics by peephole BPF sequence.
This patch introduce new intrinsic expand infrastructure to memcpy.
To get stable in-order load/store sequence from memcpy, we first lower
memcpy into BPF::MEMCPY node which then expanded into in-order load/store
sequences in expandPostRAPseudo pass which will happen after instruction
scheduling. By this way, kernel JIT backends could reliably recognize
memcpy through scanning BPF sequence.
This new memcpy expand infrastructure is gated by a new option:
-bpf-expand-memcpy-in-order
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 337977
Yonghong Song