diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index 063a8579052..7401047563f 100644
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -598,14 +598,20 @@ optimizations.extend([
     ('fsat', ('fadd', ('fneg',  a), b)), '!options->lower_fsat'),
 
    (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)),
-   (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))),
-   (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)),
-   (('~ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))),
-   (('~ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('fmax', a, b), c)),
-   (('~ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('fmax', b, c))),
-   (('~ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('fmin', a, b), c)),
-   (('~ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('fmin', b, c))),
-   (('~ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('fmax', a, b), c)),
+
+   # The ior versions are exact because fmin and fmax will always pick a
+   # non-NaN value, if one exists.  Therefore (a < NaN) || (a < c) == a <
+   # fmax(NaN, c) == a < c.  Mark the fmin or fmax in the replacement as exact
+   # to prevent other optimizations from ruining the "NaN clensing" property
+   # of the fmin or fmax.
+   (('ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('!fmax', b, c))),
+   (('ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('!fmin', a, b), c)),
+   (('ior', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('!fmin', b, c))),
+   (('ior', ('fge(is_used_once)', a, c), ('fge', b, c)), ('fge', ('!fmax', a, b), c)),
+   (('ior', ('flt', a, '#b'), ('flt', a, '#c')), ('flt', a, ('!fmax', b, c))),
+   (('ior', ('flt', '#a', c), ('flt', '#b', c)), ('flt', ('!fmin', a, b), c)),
+   (('ior', ('fge', a, '#b'), ('fge', a, '#c')), ('fge', a, ('!fmin', b, c))),
+   (('ior', ('fge', '#a', c), ('fge', '#b', c)), ('fge', ('!fmax', a, b), c)),
    (('~iand', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmin', b, c))),
    (('~iand', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmax', a, b), c)),
    (('~iand', ('fge(is_used_once)', a, b), ('fge', a, c)), ('fge', a, ('fmax', b, c))),
@@ -643,10 +649,10 @@ for s in [16, 32, 64]:
        # used once as this ensures that the number of comparisons will not
        # increase.  The sources to the ior and iand are not symmetric, so the
        # rules have to be duplicated to get this behavior.
-       (('~ior', ('flt(is_used_once)', 0.0, 'a@{}'.format(s)), ('flt', 'b@{}'.format(s), 0.0)), ('flt', 0.0, ('fmax', a, ('fneg', b)))),
-       (('~ior', ('flt', 0.0, 'a@{}'.format(s)), ('flt(is_used_once)', 'b@{}'.format(s), 0.0)), ('flt', 0.0, ('fmax', a, ('fneg', b)))),
-       (('~ior', ('fge(is_used_once)', 0.0, 'a@{}'.format(s)), ('fge', 'b@{}'.format(s), 0.0)), ('fge', 0.0, ('fmin', a, ('fneg', b)))),
-       (('~ior', ('fge', 0.0, 'a@{}'.format(s)), ('fge(is_used_once)', 'b@{}'.format(s), 0.0)), ('fge', 0.0, ('fmin', a, ('fneg', b)))),
+       (('ior', ('flt(is_used_once)', 0.0, 'a@{}'.format(s)), ('flt', 'b@{}'.format(s), 0.0)), ('flt', 0.0, ('fmax', a, ('fneg', b)))),
+       (('ior', ('flt', 0.0, 'a@{}'.format(s)), ('flt(is_used_once)', 'b@{}'.format(s), 0.0)), ('flt', 0.0, ('fmax', a, ('fneg', b)))),
+       (('ior', ('fge(is_used_once)', 0.0, 'a@{}'.format(s)), ('fge', 'b@{}'.format(s), 0.0)), ('fge', 0.0, ('fmin', a, ('fneg', b)))),
+       (('ior', ('fge', 0.0, 'a@{}'.format(s)), ('fge(is_used_once)', 'b@{}'.format(s), 0.0)), ('fge', 0.0, ('fmin', a, ('fneg', b)))),
        (('~iand', ('flt(is_used_once)', 0.0, 'a@{}'.format(s)), ('flt', 'b@{}'.format(s), 0.0)), ('flt', 0.0, ('fmin', a, ('fneg', b)))),
        (('~iand', ('flt', 0.0, 'a@{}'.format(s)), ('flt(is_used_once)', 'b@{}'.format(s), 0.0)), ('flt', 0.0, ('fmin', a, ('fneg', b)))),
        (('~iand', ('fge(is_used_once)', 0.0, 'a@{}'.format(s)), ('fge', 'b@{}'.format(s), 0.0)), ('fge', 0.0, ('fmax', a, ('fneg', b)))),