i965/fs: Fail the shader compile instead of asserting when we can't spill

Blorp doesn't handle spilling so we set allow_spilling to false in that
case.  The blorp 16x MSAA resolve shader spills in 16-wide but not 8-wide.
This commit makes it so that we fail the 16-wide compile and successfully
fall back to 8-wide instead of just assert-failing when trying to compile
the 16-wide shader.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index d0b55ae..75642d3 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -5906,6 +5906,9 @@ fs_visitor::allocate_registers(bool allow_spilling)
    }
 
    if (!allocated_without_spills) {
+      if (!allow_spilling)
+         fail("Failure to register allocate and spilling is not allowed.");
+
       /* We assume that any spilling is worse than just dropping back to
        * SIMD8.  There's probably actually some intermediate point where
        * SIMD16 with a couple of spills is still better.
@@ -5930,8 +5933,6 @@ fs_visitor::allocate_registers(bool allow_spilling)
       }
    }
 
-   assert(last_scratch == 0 || allow_spilling);
-
    /* This must come after all optimization and register allocation, since
     * it inserts dead code that happens to have side effects, and it does
     * so based on the actual physical registers in use.