https://bugs.freedesktop.org/show_bug.cgi?id=85596

Lauri Kasanen curaga@operamail.com changed:

What |Removed |Added ---------------------------------------------------------------------------- Depends on| |74868, 81683, 69623

https://bugs.freedesktop.org/show_bug.cgi?id=85596

--- Comment #2 from Vadim Girlin ptpzz@yandex.ru --- (In reply to Lauri Kasanen from comment #0)

Many big shaders that currently fail with r600_shader_select - Failed to build shader variant (type=1) -12 r600_shader_from_tgsi - GPR limit exceeded - shader requires foo registers

would actually work if the GPR check was moved to after SB, as SB reduces the GPR usage quite nicely.

Another thing is that 128 is the lowest common denominator, and many cards have 192 or 256, which could be checked with the radeon_info ioctl.

As Alex said, ISA encoding doesn't allow to address more than 128 registers in the instructions. IIRC we also by default reserve 4 GPRs as temporary (they are not preserved between ALU clauses), so the actual limit is 124 (or even 120?).

It's also the reason why we can't simply move the GPR check, the shader is passed from TGSI translator to SB in the ISA encoding which can't represent the code that uses more than 128 registers.

If anyone would like to revive a direct TGSI->SB translator that solves the problem, here is the branch: http://cgit.freedesktop.org/~vadimg/mesa/log/?h=wip-sb-tgsi There were no piglit regressions with that branch on evergreen when it was implemented, but now I suspect it's a bit outdated.

https://bugs.freedesktop.org/show_bug.cgi?id=85596 Bug 85596 depends on bug 69623, which changed state.

Bug 69623 Summary: Pink Pony misrenders - - shader requires 126 registers https://bugs.freedesktop.org/show_bug.cgi?id=69623

What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED

https://bugs.freedesktop.org/show_bug.cgi?id=85596

GitLab Migration User gitlab-migration@fdo.invalid changed:

What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |MOVED

--- Comment #4 from GitLab Migration User gitlab-migration@fdo.invalid --- -- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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