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enable Integer#sqrt #5367

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Merged
merged 1 commit into from
Oct 14, 2018
Merged

enable Integer#sqrt #5367

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3 changes: 1 addition & 2 deletions core/src/main/java/org/jruby/RubyFixnum.java
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Original file line number Diff line number Diff line change
Expand Up @@ -1452,8 +1452,7 @@ public IRubyObject sqrt(ThreadContext context) {
}

long n = value;
// FIXME: this is obviously not super efficient, but floorSqrt(long) did not pass tests
long sq = floorSqrt(BigInteger.valueOf(n)).longValue();
long sq = floorSqrt(n);

return RubyFixnum.newFixnum(runtime, sq);
}
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10 changes: 5 additions & 5 deletions core/src/main/java/org/jruby/RubyInteger.java
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Expand Up @@ -150,13 +150,13 @@ public static IRubyObject sqrt(ThreadContext context, IRubyObject self, IRubyObj

public abstract IRubyObject sqrt(ThreadContext context);

// floorSqrt :: unsigned long -> unsigned int
// floorSqrt :: unsigned long -> unsigned long
// Gives the exact floor of the square root of x, treated as unsigned.
// Public domain code from http://www.codecodex.com/wiki/Calculate_an_integer_square_root
public static final int floorSqrt(final long x) {
if ((x & 0xfff0000000000000L) == 0L) return (int) StrictMath.sqrt(x);
final long result = (long) StrictMath.sqrt(2.0d*(x >>> 1));
return result*result - x > 0L ? (int) result - 1 : (int) result;
public static final long floorSqrt(final long x) {
if ((x & 0xfff0000000000000L) == 0L) return (long) StrictMath.sqrt(x);
final long result = (long) StrictMath.sqrt(2.0d*(x >>> 1));
return result*result - x > 0L ? (long) result - 1 : (long) result;
}

// floorSqrt :: BigInteger -> BigInteger
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