nir: Recognize a pattern for doing b2f without the opcode.

Since we have patterns based on b2f, generate them if we see the b2f
equivalent using an iand.  This is common when generating NIR from TGSI.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 66b456d1164d4016d8085507f0349a60103a9c66..301d7a8ebcf59a5d9a0a33139da1c944648a6df2 100644 (file)
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -99,6 +99,7 @@ optimizations = [
    # Emulating booleans
    (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))),
    (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))),
+   (('iand', 'a@bool', 1.0), ('b2f', a)),
    # Comparison with the same args.  Note that these are not done for
    # the float versions because NaN always returns false on float
    # inequalities.