From 377fe4c984c729754a0169500e1ee406b88e72d3 Mon Sep 17 00:00:00 2001
From: Simon Byrne <simonbyrne@gmail.com>
Date: Mon, 29 Jun 2015 17:11:04 +0100
Subject: [PATCH] add div function for BigFloats

---
 base/mpfr.jl | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 test/mpfr.jl |  9 ++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/base/mpfr.jl b/base/mpfr.jl
index 5d6aaf88ce6b7..9f449c6747721 100644
--- a/base/mpfr.jl
+++ b/base/mpfr.jl
@@ -12,7 +12,7 @@ export
 
 import
     Base: (*), +, -, /, <, <=, ==, >, >=, ^, besselj, besselj0, besselj1, bessely,
-        bessely0, bessely1, ceil, cmp, convert, copysign, deg2rad,
+        bessely0, bessely1, ceil, cmp, convert, copysign, deg2rad, div,
         exp, exp2, exponent, factorial, floor, fma, hypot, isinteger,
         isfinite, isinf, isnan, ldexp, log, log2, log10, max, min, mod, modf,
         nextfloat, prevfloat, promote_rule, rad2deg, rem, round, show,
@@ -309,6 +309,65 @@ function fma(x::BigFloat, y::BigFloat, z::BigFloat)
     return r
 end
 
+# div
+# BigFloat
+function div(x::BigFloat, y::BigFloat)
+    z = BigFloat()
+    ccall((:mpfr_div,:libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}, Ptr{BigFloat}, Int32), &z, &x, &y, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+
+# Unsigned Int
+function div(x::BigFloat, c::CulongMax)
+    z = BigFloat()
+    ccall(($(string(:mpfr_div_ui)), :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}, Culong, Int32), &z, &x, c, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+function div(c::CulongMax, x::BigFloat)
+    z = BigFloat()
+    ccall((:mpfr_ui_div, :libmpfr), Int32, (Ptr{BigFloat}, Culong, Ptr{BigFloat}, Int32), &z, c, &x, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+
+# Signed Integer
+function div(x::BigFloat, c::ClongMax)
+    z = BigFloat()
+    ccall((:mpfr_div_si, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}, Clong, Int32), &z, &x, c, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+function div(c::ClongMax, x::BigFloat)
+    z = BigFloat()
+    ccall((:mpfr_si_div, :libmpfr), Int32, (Ptr{BigFloat}, Clong, Ptr{BigFloat}, Int32), &z, c, &x, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+
+# Float32/Float64
+function div(x::BigFloat, c::CdoubleMax)
+    z = BigFloat()
+    ccall((:mpfr_div_d, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}, Cdouble, Int32), &z, &x, c, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+function div(c::CdoubleMax, x::BigFloat)
+    z = BigFloat()
+    ccall((:mpfr_d_div, :libmpfr), Int32, (Ptr{BigFloat}, Cdouble, Ptr{BigFloat}, Int32), &z, c, &x, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+
+# BigInt
+function div(x::BigFloat, c::BigInt)
+    z = BigFloat()
+    ccall((:mpfr_div_z, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}, Ptr{BigInt}, Int32), &z, &x, &c, to_mpfr(RoundToZero))
+    ccall((:mpfr_trunc, :libmpfr), Int32, (Ptr{BigFloat}, Ptr{BigFloat}), &z, &z)
+    return z
+end
+
 
 
 # More efficient commutative operations
diff --git a/test/mpfr.jl b/test/mpfr.jl
index d24ebe0e23cc3..457a8ffba892f 100644
--- a/test/mpfr.jl
+++ b/test/mpfr.jl
@@ -729,6 +729,15 @@ f = parse(BigFloat,"6.2230152778611417071440640537801242405902521687211671331011
 # BigInt division
 @test a / BigInt(2) == c
 
+# div
+@test div(big"1.0",big"0.1") == 9
+@test div(1,big"0.1") == 9
+@test div(1.0,big"0.1") == 9
+@test div(big"1.0",0.1) == 9
+@test div(big"1",big"0.1") == 9
+@test div(big"1",0.1) == 9
+
+
 # old tests
 tol = 1e-12