nir: Simplify a bcsel to logical-or

Graphics / Mesa 3D Graphics Library / Mesa - Ian Romanick [intel.com] - 31 March 2016 16:59 UTC

Oddly, this did not affect the shader where I first noticed the pattern. That particular shader doesn't get its if-statement converted to a bcsel because there are two assignments in the else-statement. This led to me submitting https://bugs.freedesktop.org/show_bug.cgi?id=94747.

shader-db results:

Sandy Bridge total instructions in shared programs: 8467384 -> 8467069 (-0.00%) instructions in affected programs: 36594 -> 36279 (-0.86%) helped: 46 HURT: 0

total cycles in shared programs: 117573448 -> 117568518 (-0.00%) cycles in affected programs: 339114 -> 334184 (-1.45%) helped: 46 HURT: 0

Ivy Bridge / Haswell / Broadwell / Skylake: total instructions in shared programs: 7774258 -> 7773999 (-0.00%) instructions in affected programs: 30874 -> 30615 (-0.84%) helped: 46 HURT: 0

total cycles in shared programs: 65739190 -> 65734530 (-0.01%) cycles in affected programs: 180380 -> 175720 (-2.58%) helped: 45 HURT: 1

No change on G45 or Ironlake.

I also tried these expressions, but none of them affected any shaders in shader-db:

(('bcsel', a, 'a@bool', 'b@bool'), ('ior', a, b)), (('bcsel', a, 'b@bool', False), ('iand', a, b)), (('bcsel', a, 'b@bool', 'a@bool'), ('iand', a, b)),

08ff5f4 nir: Simplify a bcsel to logical-or
src/compiler/nir/nir_opt_algebraic.py | 1 +
1 file changed, 1 insertion(+)

Upstream: cgit.freedesktop.org

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