rand: rearrange code to test fixnump first.

* rand.c (random): The fixnump is going to come up more often
than bignum, and is also fast to test for since fixnums are
identified by just the tag in value word.

1 files changed, 46 insertions, 46 deletions

diff --git a/rand.c b/rand.c
index 4610d8f7..ad79c523 100644
--- a/rand.c
+++ b/rand.c
@@ -367,52 +367,7 @@ val random(val state, val modulus)
                                 cobj_handle(self, state, random_state_cls));
   mp_int *m;
 
-  if (bignump(modulus) && !mp_isneg(m = mp(modulus))) {
-    ucnum bits = mp_count_bits(m) - mp_is_pow_two(m);
-    ucnum rands_needed = (bits + 32 - 1) / 32;
-    ucnum msb_rand_bits = bits % 32;
-    rand32_t msb_rand_mask = convert(rand32_t, -1) >> (msb_rand_bits
-                                                       ? 32 - msb_rand_bits
-                                                       : 0);
-    val out = make_bignum();
-    mp_int *om = mp(out);
-
-    for (;;) {
-      ucnum i;
-      for (i = 0; i < rands_needed; i++) {
-        rand32_t rnd = rand32(r);
-        mp_err mpe = MP_OKAY;
-#if MP_DIGIT_SIZE >= 4
-        if (i > 0)
-          mpe = mp_mul_2d(om, 32, om);
-        else
-          rnd &= msb_rand_mask;
-        if (mpe == MP_OKAY)
-          mpe = mp_add_d(om, rnd, om);
-#else
-        if (i > 0)
-          mpe = mp_mul_2d(om, 16, om);
-        else
-          rnd &= msb_rand_mask;
-        if (mpe == MP_OKAY)
-          mpe = mp_add_d(om, rnd & 0xFFFF, om);
-        if (mpe == MP_OKAY)
-          mpe = mp_mul_2d(om, 16, om);
-        if (mpe == MP_OKAY)
-          mp_add_d(om, rnd >> 16, om);
-#endif
-        if (mpe != MP_OKAY)
-          do_mp_error(self, mpe);
-      }
-      if (mp_cmp(om, m) != MP_LT) {
-        mp_zero(om);
-        continue;
-      }
-      break;
-    }
-
-    return normalize(out);
-  } else if (fixnump(modulus)) {
+  if (fixnump(modulus)) {
     cnum m = c_num(modulus, self);
     if (m == 1) {
       return zero;
@@ -583,6 +538,51 @@ val random(val state, val modulus)
     default:
       break;
     }
+  } else if (bignump(modulus) && !mp_isneg(m = mp(modulus))) {
+    ucnum bits = mp_count_bits(m) - mp_is_pow_two(m);
+    ucnum rands_needed = (bits + 32 - 1) / 32;
+    ucnum msb_rand_bits = bits % 32;
+    rand32_t msb_rand_mask = convert(rand32_t, -1) >> (msb_rand_bits
+                                                       ? 32 - msb_rand_bits
+                                                       : 0);
+    val out = make_bignum();
+    mp_int *om = mp(out);
+
+    for (;;) {
+      ucnum i;
+      for (i = 0; i < rands_needed; i++) {
+        rand32_t rnd = rand32(r);
+        mp_err mpe = MP_OKAY;
+#if MP_DIGIT_SIZE >= 4
+        if (i > 0)
+          mpe = mp_mul_2d(om, 32, om);
+        else
+          rnd &= msb_rand_mask;
+        if (mpe == MP_OKAY)
+          mpe = mp_add_d(om, rnd, om);
+#else
+        if (i > 0)
+          mpe = mp_mul_2d(om, 16, om);
+        else
+          rnd &= msb_rand_mask;
+        if (mpe == MP_OKAY)
+          mpe = mp_add_d(om, rnd & 0xFFFF, om);
+        if (mpe == MP_OKAY)
+          mpe = mp_mul_2d(om, 16, om);
+        if (mpe == MP_OKAY)
+          mp_add_d(om, rnd >> 16, om);
+#endif
+        if (mpe != MP_OKAY)
+          do_mp_error(self, mpe);
+      }
+      if (mp_cmp(om, m) != MP_LT) {
+        mp_zero(om);
+        continue;
+      }
+      break;
+    }
+
+    return normalize(out);
   }
 
   uw_throwf(numeric_error_s, lit("~a: invalid modulus ~s"),