Add rem2pi (#544)

* Add rem2pi

* fix

src/compiler.jl

@@ -29,6 +29,7 @@ unsafe_to_pointer(ptr) = ccall(Base.@cfunction(x->x, Ptr{Cvoid}, (Ptr{Cvoid},)),
 # Julia function to LLVM stem and arity
 const known_ops = Dict(
     Base.cbrt => (:cbrt, 1),
+    Base.rem2pi => (:jl_rem2pi, 2),
     Base.sqrt => (:sqrt, 1),
     Base.sin => (:sin, 1),
     Base.sinc => (:sincn, 1),
@@ -6044,6 +6045,7 @@ end
            elseif sparam_vals[2] != T
               continue
            end
+        elseif name == :jl_rem2pi
         else
            all(==(T), sparam_vals) || continue
         end
@@ -6060,7 +6062,7 @@ end
         handleCustom(name, [EnumAttribute("readnone", 0; ctx),
                     StringAttribute("enzyme_shouldrecompute"; ctx)])
     end
-    
+
     @assert actualRetType !== nothing
 
     if must_wrap

src/compiler/interpreter.jl

@@ -88,6 +88,11 @@ function is_primitive_func(@nospecialize(TT))
     if in(ft, PrimitiveFuncs)
        return true
     end
+    if ft === typeof(Base.rem2pi)
+        if TT <: Tuple{ft, Float32, <:Any} || TT <: Tuple{ft, Float64, <:Any} || TT <: Tuple{ft, Float16, <:Any}
+            return true
+        end
+    end
     if ft === typeof(Base.cbrt) || ft === typeof(Base.sin) || ft === typeof(Base.cos) ||
        ft === typeof(Base.sinc) ||
        ft === typeof(Base.tan) || ft === typeof(Base.exp) || ft === typeof(Base.FastMath.exp_fast) ||

test/runtests.jl

@@ -146,6 +146,7 @@ end
     test_scalar(Base.exp10, 1.0)
     test_scalar(Base.exp2, 1.0)
     test_scalar(Base.expm1, 1.0)
+    test_scalar(x->rem2pi(x,RoundDown), 0.7)
 
     @test autodiff(Reverse, (x)->log(x), Active(2.0)) == (0.5,)
 end