//===--- tgmath.swift.gyb -------------------------------------*- swift -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

import SwiftShims

// Generic functions implementable directly on FloatingPoint.
@_transparent
public func fabs<T: FloatingPoint>(_ x: T) -> T
  where T.Magnitude == T {
  return x.magnitude
}

@_transparent
public func sqrt<T: FloatingPoint>(_ x: T) -> T {
  return x.squareRoot()
}

@_transparent
public func fma<T: FloatingPoint>(_ x: T, _ y: T, _ z: T) -> T {
  return z.addingProduct(x, y)
}

@_transparent
public func remainder<T: FloatingPoint>(_ x: T, _ y: T) -> T {
  return x.remainder(dividingBy: y)
}

@_transparent
public func fmod<T: FloatingPoint>(_ x: T, _ y: T) -> T {
  return x.truncatingRemainder(dividingBy: y)
}

@_transparent
public func ceil<T: FloatingPoint>(_ x: T) -> T {
  return x.rounded(.up)
}

@_transparent
public func floor<T: FloatingPoint>(_ x: T) -> T {
  return x.rounded(.down)
}

@_transparent
public func round<T: FloatingPoint>(_ x: T) -> T {
  return x.rounded()
}

@_transparent
public func trunc<T: FloatingPoint>(_ x: T) -> T {
  return x.rounded(.towardZero)
}

%{

# Don't need 64-bit (Double/CDouble) overlays. The ordinary C imports work fine.
# FIXME: need 80-bit (Float80/long double) versions when long double is imported
overlayFloatBits = [32] # 80
allFloatBits = [32, 64] # 80

def floatName(bits):
    if bits == 32:
        return 'Float'
    if bits == 64:
        return 'Double'
    if bits == 80:
        return 'Float80'

def cFloatName(bits):
    if bits == 32:
        return 'CFloat'
    if bits == 64:
        return 'CDouble'
    if bits == 80:
        return 'CLongDouble'

def cFuncSuffix(bits):
    if bits == 32:
        return 'f'
    if bits == 64:
        return ''
    if bits == 80:
        return 'l'

# Each of the following lists is ordered to match math.h

# (T) -> T
# These functions do not have a corresponding LLVM intrinsic
UnaryFunctions = [
    'acos', 'asin', 'atan', 'tan',
    'acosh', 'asinh', 'atanh', 'cosh', 'sinh', 'tanh',
    'expm1',
    'log1p', 'logb',
    'cbrt', 'erf', 'erfc', 'tgamma',
]

# These functions have a corresponding LLVM intrinsic
# We call this intrinsic via the Builtin method so keep this list in
# sync with core/BuiltinMath.swift.gyb
UnaryIntrinsicFunctions = [
    'cos', 'sin',
    'exp', 'exp2',
    'log', 'log10', 'log2',
    'nearbyint', 'rint',
]

# (T, T) -> T
BinaryFunctions = [
    'atan2', 'hypot', 'pow',
    'copysign', 'nextafter', 'fdim', 'fmax', 'fmin'
]

# These functions have special implementations.
OtherFunctions = [
    'fpclassify',
    'isnormal', 'isfinite', 'isinf', 'isnan', 'signbit',
    'modf', 'ldexp', 'frexp', 'ilogb', 'scalbn', 'lgamma',
    'remquo', 'nan',
    'jn', 'yn'
]

# These functions are imported correctly as-is.
OkayFunctions = ['j0', 'j1', 'y0', 'y1']

# These functions are not supported for various reasons.
UnhandledFunctions = [
    'math_errhandling', 'scalbln',
    'lrint', 'lround', 'llrint', 'llround', 'nexttoward',
    'isgreater', 'isgreaterequal', 'isless', 'islessequal',
    'islessgreater', 'isunordered', '__exp10',
    '__sincos', '__cospi', '__sinpi', '__tanpi', '__sincospi'
]


def AllFloatTypes():
    for bits in allFloatBits:
        yield floatName(bits), cFloatName(bits), cFuncSuffix(bits)

def OverlayFloatTypes():
    for bits in overlayFloatBits:
        yield floatName(bits), cFloatName(bits), cFuncSuffix(bits)

def TypedUnaryFunctions():
    for ufunc in UnaryFunctions:
        for bits in overlayFloatBits:
            yield floatName(bits), cFloatName(bits), cFuncSuffix(bits), ufunc

def TypedUnaryIntrinsicFunctions():
    for ufunc in UnaryIntrinsicFunctions:
        for bits in allFloatBits:
            yield floatName(bits), ufunc

def TypedBinaryFunctions():
    for bfunc in BinaryFunctions:
        for bits in overlayFloatBits:
            yield floatName(bits), cFloatName(bits), cFuncSuffix(bits), bfunc

}%

// Unary functions
// Note these do not have a corresponding LLVM intrinsic
% for T, CT, f, ufunc in TypedUnaryFunctions():
@_transparent
public func ${ufunc}(_ x: ${T}) -> ${T} {
  return ${T}(${ufunc}${f}(${CT}(x)))
}

% end

#if os(OSX) || os(iOS) || os(tvOS) || os(watchOS)
// Unary intrinsic functions
// Note these have a corresponding LLVM intrinsic
% for T, ufunc in TypedUnaryIntrinsicFunctions():
@_transparent
public func ${ufunc}(_ x: ${T}) -> ${T} {
  return _${ufunc}(x)
}

% end
#else
// FIXME: As of now, we cannot declare 64-bit (Double/CDouble) overlays here.
// Since CoreFoundation also exports libc functions, they will conflict with
// Swift overlays when building Foundation. For now, just like normal
// UnaryFunctions, we define overlays only for OverlayFloatTypes.
% for ufunc in UnaryIntrinsicFunctions:
%     for T, CT, f in OverlayFloatTypes():
@_transparent
public func ${ufunc}(_ x: ${T}) -> ${T} {
  return ${T}(${ufunc}${f}(${CT}(x)))
}

%     end
% end
#endif

// Binary functions

% for T, CT, f, bfunc in TypedBinaryFunctions():
@_transparent
public func ${bfunc}(_ lhs: ${T}, _ rhs: ${T}) -> ${T} {
  return ${T}(${bfunc}${f}(${CT}(lhs), ${CT}(rhs)))
}

% end

// Other functions
% for T, CT, f in AllFloatTypes():
@available(*, deprecated, message: "use the floatingPointClass property.")
public func fpclassify(_ value: ${T}) -> Int {
%if T == 'Double':
#if os(Linux) || os(Haiku)
  return Int(__fpclassify(CDouble(value)))
#elseif os(Windows) 
  return Int(_dclass(CDouble(value)))
#else
  return Int(__fpclassifyd(CDouble(value)))
#endif
%else:
#if os(Windows) 
  return Int(_${f}dclass(${CT}(value)))
#else
  return Int(__fpclassify${f}(${CT}(value)))
#endif
%end
}

@available(*, unavailable, message: "use the isNormal property.")
public func isnormal(_ value: ${T}) -> Bool { return value.isNormal }

@available(*, unavailable, message: "use the isFinite property.")
public func isfinite(_ value: ${T}) -> Bool { return value.isFinite }

@available(*, unavailable, message: "use the isInfinite property.")
public func isinf(_ value: ${T}) -> Bool { return value.isInfinite }

@available(*, unavailable, message: "use the isNaN property.")
public func isnan(_ value: ${T}) -> Bool { return value.isNaN }

@available(*, unavailable, message: "use the sign property.")
public func signbit(_ value: ${T}) -> Int { return value.sign.rawValue }

% end

% # These are AllFloatTypes not OverlayFloatTypes because of the tuple return.
% for T, CT, f in AllFloatTypes():
@_transparent
public func modf(_ value: ${T}) -> (${T}, ${T}) {
  var ipart = ${CT}(0)
  let fpart = modf${f}(${CT}(value), &ipart)
  return (${T}(ipart), ${T}(fpart))
}

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the Int parameter.
% for T, CT, f in AllFloatTypes():
@_transparent
public func ldexp(_ x: ${T}, _ n: Int) -> ${T} {
  return ${T}(ldexp${f}(${CT}(x), Int32(n)))
}

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the tuple return.
% for T, CT, f in AllFloatTypes():
@_transparent
public func frexp(_ value: ${T}) -> (${T}, Int) {
  var exp = Int32(0)
  let frac = frexp${f}(${CT}(value), &exp)
  return (${T}(frac), Int(exp))
}

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the Int return.
% for T, CT, f in AllFloatTypes():
@_transparent
public func ilogb(_ x: ${T}) -> Int {
  return Int(ilogb${f}(${CT}(x)) as Int32)
}

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the Int parameter.
% for T, CT, f in AllFloatTypes():
@_transparent
public func scalbn(_ x: ${T}, _ n: Int) -> ${T} {
  return ${T}(scalbn${f}(${CT}(x), Int32(n)))
}

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the tuple return.
% for T, CT, f in AllFloatTypes():
#if os(Linux) || os(FreeBSD) || os(PS4) || os(Android) || os(Cygwin) || os(Haiku)
@_transparent
public func lgamma(_ x: ${T}) -> (${T}, Int) {
  var sign = Int32(0)
  let value = lgamma${f}_r(${CT}(x), &sign)
  return (${T}(value), Int(sign))
}
#elseif os(Windows)
// TODO(compnerd): implement
#else
% # On Darwin platforms the real lgamma_r is not imported
% # because it hides behind macro _REENTRANT.
% # This is not @transparent because _stdlib_lgamma() is not public.
public func lgamma(_ x: ${T}) -> (${T}, Int) {
  var sign = Int32(0)
  let value = withUnsafeMutablePointer(to: &sign) {
    (signp: UnsafeMutablePointer<Int32>) -> ${CT} in
    return _stdlib_lgamma${f}_r(${CT}(x), signp)
  }
  return (${T}(value), Int(sign))
}
#endif

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the tuple return.
% for T, CT, f in AllFloatTypes():
@_transparent
public func remquo(_ x: ${T}, _ y: ${T}) -> (${T}, Int) {
  var quo = Int32(0)
  let rem = remquo${f}(${CT}(x), ${CT}(y), &quo)
  return (${T}(rem), Int(quo))
}

% end

% for T, CT, f in OverlayFloatTypes():
@_transparent
public func nan(_ tag: String) -> ${T} {
  return ${T}(nan${f}(tag))
}

% end

% # These C functions only support double. The overlay fixes the Int parameter.
@_transparent
public func jn(_ n: Int, _ x: Double) -> Double {
#if os(Windows)
  return _jn(Int32(n), x)
#else
  return jn(Int32(n), x)
#endif
}

@_transparent
public func yn(_ n: Int, _ x: Double) -> Double {
#if os(Windows)
  return _yn(Int32(n), x)
#else
  return yn(Int32(n), x)
#endif
}

% end

// ${'Local Variables'}:
// eval: (read-only-mode 1)
// End: