[PATCH] D109073: BPF: make 32bit register spill with 64bit alignment

[Yonghong Song via Phabricator via llvm-commits]

yonghong-song added a comment.

The following is the kernel bpf_verif_scale self test results w.r.t. stack size.

  bpf selftest bpf_verif_scale (-mcpu=v3):
  test_id  subtest name            old stack size   new stack size
  12/1     loop3.o                 0                0
  12/2     test_verif_scale1.o     8+0              8+0
  12/3     test_verif_scale2.o     8                8
  12/4     test_verif_scale3.o     8+0              8+0
  12/5     pyperf_global.o         0+352            0+352
  12/6     pyperf_subprogs.o       0+352+12         0+352+12
  12/7     pyperf50.o              352              352
  12/8     pyperf100.o             352              352
  12/9     pyperf180.o             344              344
  12/10    pyperf600.o             368              368
  12/11    pyperf600_nounroll.o    320              320
  12/12    loop1.o                 0                0
  12/13    loop2.o                 0                0
  12/14    loop4.o                 0                0
  12/15    loop5.o                 0                0
  12/16    loop6.o                 64               64
  12/17    strobemeta.o            496              496
  12/18    strobemeta_nounroll1.o  488              488
  12/19    strobemeta_nounroll2.o  488              488
  12/20    strobemeta_subprogs.o   24+416+0+32      24+416+0+32
  12/21    test_sysctl_loop1.o     428              428
  12/22    test_sysctl_loop2.o     300+80           300+80
  12/23    test_xdp_loop.o         36               40
  12/24    test_seg6_loop.o        88               96

Only `test_xdp_loop.o` and `test_seg6_loop.o' has a small increase. Overall, it seems the impact on stack size should be moderate.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D109073/new/

https://reviews.llvm.org/D109073