[Mesa-dev] [PATCH 00/21] i965: Implement non-coherent framebuffer fetch.

[Francisco Jerez]

This is an implementation of non-coherent framebuffer fetch as
described here [1] working on most hardware generations supported
by the i965 driver (from Gen5 to Gen8).  My plan was to send the
coherent framebuffer fetch implementation for SKL+ first since
it's actually simpler than the non-coherent path, but I've
noticed some potential hardware issues that need further
investigation, so here's the non-coherent path so it hopefully
gets some reviews in the meantime -- I plan to send the
implementation of coherent framebuffer fetch next week.

Patches 01-11 get the compiler ready for non-coherent framebuffer
fetch (some of the changes like the NIR fragment output location
rework will also be useful for the coherent path).  Patches 12-20
implement the required state setup logic and the new glBlendBarrier
entry point.

You can find the whole series along with the driver-independent
changes for EXT_shader_framebuffer_fetch in my Mesa tree [2], but note
that in order to test it you still need to add an additional entry to
extensions_table.h manually since the non-coherent extension is not
exposed yet.

[1] https://lists.freedesktop.org/archives/mesa-dev/2016-July/124028.html
[2] https://cgit.freedesktop.org/~currojerez/mesa/log/?h=i965-fb-fetch

[PATCH 01/21] i965/fs: Get rid of fs_visitor::do_dual_src.
[PATCH 02/21] i965/fs: Add brw_wm_prog_key bit specifying whether FB reads should be coherent.
[PATCH 03/21] i965: Allocate space in the binding table for non-coherent FB fetch.
[PATCH 04/21] i965/fs: Force per-sample dispatch if the shader reads from a multisample FBO.
[PATCH 05/21] i965/fs: Emit interpolation setup if non-coherent framebuffer fetch is in use.
[PATCH 06/21] i965/fs: Implement non-coherent framebuffer fetch using the sampler unit.
[PATCH 07/21] i965/fs: Special-case nir_intrinsic_store_output for the fragment shader.
[PATCH 08/21] i965: Fix undefined signed overflow in INTEL_MASK for bitfields of 31 bits.
[PATCH 09/21] i965/fs: Rework representation of fragment output locations in NIR.
[PATCH 10/21] i965/fs: Allocate fragment output temporaries on demand.
[PATCH 11/21] i965/fs: Translate nir_intrinsic_load_output on a fragment output.
[PATCH 12/21] i965: Return whether the miptree was resolved from intel_miptree_resolve_color().
[PATCH 13/21] i965: Resolve color for non-coherent FB fetch at UpdateState time.
[PATCH 14/21] i965: Factor out isl_surf_dim/isl_dim_layout calculation into functions.
[PATCH 15/21] i965: Return the correct layout from get_isl_dim_layout for pre-ILK cube textures.
[PATCH 16/21] i965: Add missing has_surface_tile_offset flag to the Gen8+ device info structures.
[PATCH 17/21] i965: Massage argument list of brw_emit_surface_state().
[PATCH 18/21] i965: Implement support for overriding the texture target in brw_emit_surface_state.
[PATCH 19/21] i965: Upload surface state for non-coherent framebuffer fetch.
[PATCH 20/21] i965: Implement glBlendBarrier.
[PATCH 21/21] i965: Flip the non-coherent framebuffer fetch extension bit on G45-Gen8 hardware.