Revert "Use tailcall recursion to process skcms ops."

This reverts commit 7cf575c421865b23b898e7a1b9cbcd3f6ecc63da.

Reason for revert: This is a temporary revert to test for performance deltas on Pinpoint. Barring unforeseen circumstances, this CL will be relanded shortly.

Original change's description:
> Use tailcall recursion to process skcms ops.
> This is dramatically faster on M1 processors (and likely other ARMs)
> compared to a giant switch. It is also 25% faster on AMD EPYC (hsw).
> The MSVS + clang-cl configuration fails tests when SKCMS_MUSTTAIL is
> used, so SKCMS_MUSTTAIL is disabled in this configuration; I don't
> have access to a Windows machine to check the difference in actual
> code generation, but hopefully this is a negligible difference.
> Change-Id: Ie2f9569d19f3804fcf3ba77b6148fe8f5c8e13f9
> Bug: b/305974160
> Reviewed-on:
> Commit-Queue: John Stiles <>
> Reviewed-by: Brian Osman <>

Bug: b/305974160
Change-Id: I03728c1e9be80c4e8d5a0ae808fb2c977420efab
Reviewed-by: Brian Osman <>
Commit-Queue: John Stiles <>
Auto-Submit: John Stiles <>
2 files changed