optimize loops

source/mir/bignum/internal/ryu/generic_128.d

@@ -465,7 +465,7 @@ Decimal!2 generic_binary_to_decimal(T)(const T x)
  {
  auto div10vp = div10(vp);
  auto div10vm = div10(vm);
- if (div10vp <= div10vm)
+ if (div10vp == div10vm)
  break;
  vmIsTrailingZeros &= vm - div10vm * 10 == 0;
  vrIsTrailingZeros &= lastRemovedDigit == 0;
@@ -488,9 +488,8 @@ Decimal!2 generic_binary_to_decimal(T)(const T x)
  if (vm - div10vm * 10)
  break;
  vrIsTrailingZeros &= lastRemovedDigit == 0;
- lastRemovedDigit = vr.divRem10;
- vm = div10vm;
- vp = div10(vp);
+ lastRemovedDigit = cast(uint) (vr - div10vm * 10);
+ vr = vp = vm = div10vm;
  ++removed;
  }
  }
@@ -1105,6 +1104,8 @@ version(all) unittest
  "4.294967296e0", // 2^32
  "4.294967297e0", // 2^32 + 1
  "4.294967298e0", // 2^32 + 2
+
+ "-2.147483648e32",
  ])
  {
  import mir.conv: to;
@@ -1169,23 +1170,3 @@ version(all) unittest
 }
 
 // https://github.com/ulfjack/ryu/issues/156
-// in: -2.147483648E32
-// out: -2.1474836479999998E32
-
-// in: -3.1802768007018752E17
-// out: -3.180276800701875E17
-
-// in: -6.4432225704600013E18
-// out: -6.443222570460001E18
-
-// in: 1.3867957848030121E18
-// out: 1.386795784803012E18
-
-// in: 1.41027712162200013E18
-// out: 1.4102771216220001E18
-
-// in: 8.8243617212999997E18
-// out: 8.8243617213E18
-
-// in: 8.8243617212999997E18
-// out: 8.8243617213E18