i965/fs: Split final assembly code generation out of fs_visitor.
Compiling shaders requires several main steps:
1. Generating FS IR from either GLSL IR or Mesa IR
2. Optimizing the IR
3. Register allocation
4. Generating assembly code
This patch splits out step 4 into a separate class named "fs_generator."
There are several reasons for doing so:
1. Future hardware has a different instruction encoding. Splitting
this out will allow us to replace fs_generator (which relies
heavily on the brw_eu_emit.c code and struct brw_instruction) with
a new code generator that writes the new format.
2. It reduces the size of the fs_visitor monolith. (Arguably, a lot
more should be split out, but that's left for "future work.")
3. Separate namespaces allow us to make helper functions for
generating instructions in both classes: ADD() can exist in
fs_visitor and create IR, while ADD() in fs_generator() can
create brw_instructions. (Patches for this upcoming.)
Furthermore, this patch changes the order of operations slightly.
Rather than doing steps 1-4 for SIMD8, then 1-4 for SIMD16, we now:
- Do steps 1-3 for SIMD8, then repeat 1-3 for SIMD16
- Generate final assembly code for both modes together
This is because the frontend work can be done independently, but final
assembly generation needs to pack both into a single program store to
feed the GPU.
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
3 files changed