nir/algebraic: add some half packing optimizations

pipeline-db (ACO):
Totals from affected shaders:
SGPRS: 29200 -> 29200 (0.00 %)
VGPRS: 17372 -> 17372 (0.00 %)
Spilled SGPRs: 105 -> 105 (0.00 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 0 -> 0 (0.00 %) dwords per thread
Code Size: 1406576 -> 1389256 (-1.23 %) bytes
LDS: 83 -> 83 (0.00 %) blocks
Max Waves: 3976 -> 3976 (0.00 %)

pipeline-db (LLVM):
Totals from affected shaders:
SGPRS: 21320 -> 21320 (0.00 %)
VGPRS: 17056 -> 17036 (-0.12 %)
Spilled SGPRs: 22 -> 22 (0.00 %)
Spilled VGPRs: 503 -> 487 (-3.18 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 396 -> 396 (0.00 %) dwords per thread
Code Size: 1441244 -> 1423292 (-1.25 %) bytes
LDS: 463 -> 463 (0.00 %) blocks
Max Waves: 3609 -> 3611 (0.06 %)

v2: add pattern for ishr

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2271>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2271>

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index fd0007bb54d1bf8bad15cb9a6b2fee32136c7316..f9fc119505f80cbdb7d4f4e815416a290242772a 100644 (file)
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -935,6 +935,15 @@ optimizations.extend([
    (('unpack_half_2x16_split_y', ('iand', a, 0xffff0000)), ('unpack_half_2x16_split_y', a)),
    (('unpack_32_2x16_split_y', ('iand', a, 0xffff0000)), ('unpack_32_2x16_split_y', a)),
    (('unpack_64_2x32_split_y', ('iand', a, 0xffffffff00000000)), ('unpack_64_2x32_split_y', a)),
+
+   # Optimize half packing
+   (('ishl', ('pack_half_2x16', ('vec2', a, 0)), 16), ('pack_half_2x16', ('vec2', 0, a))),
+   (('ishr', ('pack_half_2x16', ('vec2', 0, a)), 16), ('pack_half_2x16', ('vec2', a, 0))),
+
+   (('iadd', ('pack_half_2x16', ('vec2', a, 0)), ('pack_half_2x16', ('vec2', 0, b))),
+    ('pack_half_2x16', ('vec2', a, b))),
+   (('ior', ('pack_half_2x16', ('vec2', a, 0)), ('pack_half_2x16', ('vec2', 0, b))),
+    ('pack_half_2x16', ('vec2', a, b))),
 ])
 
 # After the ('extract_u8', a, 0) pattern, above, triggers, there will be