fpu: Simplify 0 +/- N case in parts_addsub

Consolidate the tests for zero and anynorm.
Add comments for a few cases.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index 3246702289cd18930b5267616766e744b9f66c29..45606f8402d5f1efeb1f7d0c6f9ce794da65602b 100644 (file)
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -556,6 +556,7 @@ FloatPartsN partsN(addsub)(const FloatPartsN *a_orig,
         }
 
         if (ab_mask == float_cmask_zero) {
+            /* 0 - 0 */
             a.sign = s->float_rounding_mode == float_round_down;
             return a;
         }
@@ -581,23 +582,20 @@ FloatPartsN partsN(addsub)(const FloatPartsN *a_orig,
         }
 
         if (ab_mask == float_cmask_zero) {
+            /* 0 + 0 */
             return a;
         }
 
         if (ab_mask & float_cmask_inf) {
+            /* N + Inf or Inf + N */
             a.cls = float_class_inf;
             return a;
         }
     }
 
-    if (b.cls == float_class_zero) {
-        g_assert(is_anynorm(a.cls));
-        return a;
-    }
-
-    g_assert(a.cls == float_class_zero);
-    g_assert(is_anynorm(b.cls));
-    return b;
+    /* 0 +/- N or N +/- 0 */
+    assert((ab_mask & float_cmask_zero) && (ab_mask & float_cmask_anynorm));
+    return b.cls == float_class_zero ? a : b;
 }
 
 /*