Mesa (master): nir/algebraic: Remove unnecessary iand of [iu]bfe and bfm sources

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Module: Mesa
Branch: master
Commit: 4eeb49ea71e47899f5d9a51b8f3e1fd9762fa7ad
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=4eeb49ea71e47899f5d9a51b8f3e1fd9762fa7ad

Author: Daniel Schürmann <daniel.schuermann at campus.tu-berlin.de>
Date:   Fri Jan 25 13:56:49 2019 +0100

nir/algebraic: Remove unnecessary iand of [iu]bfe and bfm sources

The [iu]bfe and bfm instructions are defined to only use the five
least significant bits.
This optimizes a common pattern from D3D -> SPIR-V translation.

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

---

 src/compiler/nir/nir_opt_algebraic.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index c7e69c0310c..6e660dfdc02 100644
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -809,6 +809,14 @@ optimizations.extend([
               ('ubfe', 'value', 'offset', 'bits')),
     'options->lower_bitfield_extract'),
 
+   # Note that these opcodes are defined to only use the five least significant bits of 'offset' and 'bits'
+   (('ubfe', 'value', 'offset', ('iand', 31, 'bits')), ('ubfe', 'value', 'offset', 'bits')),
+   (('ubfe', 'value', ('iand', 31, 'offset'), 'bits'), ('ubfe', 'value', 'offset', 'bits')),
+   (('ibfe', 'value', 'offset', ('iand', 31, 'bits')), ('ibfe', 'value', 'offset', 'bits')),
+   (('ibfe', 'value', ('iand', 31, 'offset'), 'bits'), ('ibfe', 'value', 'offset', 'bits')),
+   (('bfm', 'bits', ('iand', 31, 'offset')), ('bfm', 'bits', 'offset')),
+   (('bfm', ('iand', 31, 'bits'), 'offset'), ('bfm', 'bits', 'offset')),
+
    (('ibitfield_extract', 'value', 'offset', 'bits'),
     ('bcsel', ('ieq', 0, 'bits'),
      0,