pan/bi: Test avoiding FADD.v2f16 hazards in scheduler

There are many of them, and integration testing of the scheduler won't hit every
case. Add targeted unit tests for the various scheduling hazards of this funny
instruction.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15072>

src/panfrost/bifrost/test/test-scheduler-predicates.cpp

@@ -107,3 +107,45 @@ TEST_F(SchedulerPredicates, RestrictionsOnModifiersOfSameCycleTemporaries)
       }
    }
 }
+
+TEST_F(SchedulerPredicates, RestrictionsOnFAddV2F16)
+{
+   bi_index x = bi_register(0);
+   bi_index y = bi_register(1);
+
+   /* Basic */
+   bi_instr *fadd = bi_fadd_v2f16_to(b, TMP(), x, x, BI_ROUND_NONE);
+
+   ASSERT_TRUE(bi_can_fma(fadd));
+   ASSERT_TRUE(bi_can_add(fadd));
+
+   /* With imbalanced abs */
+   fadd->src[0].abs = true;
+
+   ASSERT_TRUE(bi_can_fma(fadd));
+   ASSERT_TRUE(bi_can_add(fadd));
+
+   /* With equal abs */
+   fadd->src[1].abs = true;
+
+   ASSERT_FALSE(bi_can_fma(fadd));
+   ASSERT_TRUE(bi_can_add(fadd));
+
+   /* With equal abs but different sources */
+   fadd->src[1] = bi_abs(y);
+
+   ASSERT_TRUE(bi_can_fma(fadd));
+   ASSERT_TRUE(bi_can_add(fadd));
+
+   /* With clamp */
+   fadd->clamp = BI_CLAMP_CLAMP_M1_1;
+
+   ASSERT_TRUE(bi_can_fma(fadd));
+   ASSERT_FALSE(bi_can_add(fadd));
+
+   /* Impossible encoding (should never be seen) */
+   fadd->src[1] = fadd->src[0];
+
+   ASSERT_FALSE(bi_can_fma(fadd));
+   ASSERT_FALSE(bi_can_add(fadd));
+}