From 1e552b9c95a1fc8cbec5f6187bf8630b3c31cc25 Mon Sep 17 00:00:00 2001
From: Georg Lehmann <dadschoorse@gmail.com>
Date: Tue, 4 Oct 2022 14:32:50 +0200
Subject: [PATCH] nir/opt_algebraic: Mirror optimizations for find_msb_rev.

Signed-off-by: Georg Lehmann <dadschoorse@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18951>
---
 src/compiler/nir/nir_opt_algebraic.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index 834565d6ce9..39ca3be927b 100644
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -1674,12 +1674,17 @@ optimizations.extend([
    (('bcsel', ('ige', ('find_lsb', a), 0), ('find_lsb', a), -1), ('find_lsb', a)),
    (('bcsel', ('ige', ('ifind_msb', a), 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
    (('bcsel', ('ige', ('ufind_msb', a), 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
+   (('bcsel', ('ige', ('ifind_msb_rev', a), 0), ('ifind_msb_rev', a), -1), ('ifind_msb_rev', a)),
+   (('bcsel', ('ige', ('ufind_msb_rev', a), 0), ('ufind_msb_rev', a), -1), ('ufind_msb_rev', a)),
 
    (('bcsel', ('ine', a, 0), ('find_lsb', a), -1), ('find_lsb', a)),
    (('bcsel', ('ine', a, 0), ('ifind_msb', a), -1), ('ifind_msb', a)),
    (('bcsel', ('ine', a, 0), ('ufind_msb', a), -1), ('ufind_msb', a)),
+   (('bcsel', ('ine', a, 0), ('ifind_msb_rev', a), -1), ('ifind_msb_rev', a)),
+   (('bcsel', ('ine', a, 0), ('ufind_msb_rev', a), -1), ('ufind_msb_rev', a)),
 
    (('bcsel', ('ine', a, -1), ('ifind_msb', a), -1), ('ifind_msb', a)),
+   (('bcsel', ('ine', a, -1), ('ifind_msb_rev', a), -1), ('ifind_msb_rev', a)),
 
    (('~fmul', ('bcsel(is_used_once)', c, -1.0, 1.0), b), ('bcsel', c, ('fneg', b), b)),
    (('~fmul', ('bcsel(is_used_once)', c, 1.0, -1.0), b), ('bcsel', c, b, ('fneg', b))),