ensure consistent results for gcdx(0,0) with BigInt

pwl · Nov 14, 2013 · dc8652c · dc8652c
1 parent 07917e7
commit dc8652c
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/base/gmp.jl b/base/gmp.jl
@@ -313,6 +313,9 @@ powermod(x::BigInt, p::Integer, m::BigInt) = powermod(x, BigInt(p), m)
 powermod(x::BigInt, p::Integer, m::Integer) = powermod(x, BigInt(p), BigInt(m))
 
 function gcdx(a::BigInt, b::BigInt)
+ if b == 0 # shortcut this to ensure consistent results with gcdx(a,b)
+ return a < 0 ? (-a,-one(BigInt),zero(BigInt)) : (a,one(BigInt),zero(BigInt))
+ end
  g = BigInt()
  s = BigInt()
  t = BigInt()