Comment=
# 9
on bug 85579<=
/a>
from Marek Ol=C5=A1=C3=A1k
I think there are 2 ways to fix this and we should do both:
1) Fix VGPR register spilling caused by indirect addressing into lots of
registers. LLVM crashes when it attempts to do that. Those registers are ju=
st
copies of shader inputs and outputs.
2)
Step A) Implement indirect addressing for VS outputs before GS and GS input=
s.
This means that we cannot store outputs at the end of shaders (using
emit_epilogue), but we must store them when they occur as a destination
register (using emit_store).
(BTW my tessellation branch contains modifications to emit_store that make =
it
easier to re-implement it for shaders that use store instructions for outpu=
ts)
Step B) glsl_to_tgsi and/or some passes of the GLSL compiler may need to be
modified not to move ins/outs into temporaries. I think the only pass that =
does
that is the varying packing. The pass should be disabled or rewritten, beca=
use
its current implementation isn't gonna fly with our hardware and is often t=
he
cause of unnecessary register spilling.