| |
| function f56(x) { |
| var a = x >>> 0; // Range = [0 .. UINT32_MAX] (bits = 32) |
| var b = 0x800000; // == 2^23 (bits = 24) |
| if (a > 0) { |
| // Beta node: Range [1 .. UINT32_MAX] (bits = 32) |
| var c = a * b; // Range = [0 .. +inf] (bits = a.bits + b.bits - 1 = 55) |
| var d = c + 1; // Range = [0 .. +inf] (bits = c.bits + 1 = 56) |
| return (d | 0) & 1; |
| } else { |
| return 1; |
| } |
| } |
| |
| function f55(x) { |
| var a = x >>> 0; // Range = [0 .. UINT32_MAX] (bits = 32) |
| var b = 0x400000; // == 2^22 (bits = 23) |
| if (a > 0) { |
| // Beta node: Range [1 .. UINT32_MAX] (bits = 32) |
| var c = a * b; // Range = [0 .. +inf] (bits = a.bits + b.bits - 1 = 54) |
| var d = c + 1; // Range = [0 .. +inf] (bits = c.bits + 1 = 55) |
| return (d | 0) & 1; |
| } else { |
| return 1; |
| } |
| } |
| |
| // Still returns 1, because the top-level bit is not represented. |
| function f54(x) { |
| var a = x >>> 0; // Range = [0 .. UINT32_MAX] (bits = 32) |
| var b = 0x200000; // == 2^21 (bits = 22) |
| if (a > 0) { |
| // Beta node: Range [1 .. UINT32_MAX] (bits = 32) |
| var c = a * b; // Range = [0 .. +inf] (bits = a.bits + b.bits - 1 = 53) |
| var d = c + 1; // Range = [1 .. +inf] (bits = c.bits + 1 = 54) |
| return (d | 0) & 1; |
| } else { |
| return 1; |
| } |
| } |
| |
| // Can safely truncate after these operations. (the mantissa has 53 bits) |
| function f53(x) { |
| var a = x >>> 0; // Range = [0 .. UINT32_MAX] (bits = 32) |
| var b = 0x100000; // == 2^20 (bits = 21) |
| if (a > 0) { |
| // Beta node: Range [1 .. UINT32_MAX] (bits = 32) |
| var c = a * b; // Range = [0 .. +inf] (bits = a.bits + b.bits - 1 = 52) |
| var d = c + 1; // Range = [1 .. +inf] (bits = c.bits + 1 = 53) |
| return (d | 0) & 1; |
| } else { |
| return 1; |
| } |
| } |
| |
| function f52(x) { |
| var a = x >>> 0; // Range = [0 .. UINT32_MAX] (bits = 32) |
| var b = 0x80000; // == 2^19 (bits = 20) |
| if (a > 0) { |
| // Beta node: Range [1 .. UINT32_MAX] (bits = 32) |
| var c = a * b; // Range = [0 .. +inf] (bits = a.bits + b.bits - 1 = 51) |
| var d = c + 1; // Range = [1 .. +inf] (bits = c.bits + 1 = 52) |
| return (d | 0) & 1; |
| } else { |
| return 1; |
| } |
| } |
| |
| function f51(x) { |
| var a = x >>> 0; // Range = [0 .. UINT32_MAX] (bits = 32) |
| var b = 0x40000; // == 2^18 (bits = 19) |
| if (a > 0) { |
| // Beta node: Range [1 .. UINT32_MAX] (bits = 32) |
| var c = a * b; // Range = [0 .. +inf] (bits = a.bits + b.bits - 1 = 50) |
| var d = c + 1; // Range = [1 .. +inf] (bits = c.bits + 1 = 51) |
| return (d | 0) & 1; |
| } else { |
| return 1; |
| } |
| } |
| |
| var e = Math.pow(2, 32); |
| for (var i = 1; i < e; i = i * 1.5) { |
| var x = i >>> 0; |
| assertEq(f56(x) , (x >= Math.pow(2, 30)) ? 0 : 1); |
| assertEq(f55(x), (x >= Math.pow(2, 31)) ? 0 : 1); |
| assertEq(f54(x), 1); |
| assertEq(f53(x), 1); |
| assertEq(f52(x), 1); |
| assertEq(f51(x), 1); |
| } |