//===--- tgmath.swift.gyb -------------------------------------*- swift -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2019 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
@available(swift, deprecated: 4.2/*, obsoleted: 5.1*/, renamed: "abs")
public func fabs<T: FloatingPoint>(_ x: T) -> 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)
}

@_transparent
public func scalbn<T: FloatingPoint>(_ x: T, _ n : Int) -> T {
  return T(sign: .plus, exponent: T.Exponent(n), significand: x)
}

@_transparent
public func modf<T: FloatingPoint>(_ x: T) -> (T, T) {
  // inf/NaN: return canonicalized x, fractional part zero.
  guard x.isFinite else { return (x+0, 0) }
  let integral = trunc(x)
  let fractional = x - integral
  return (integral, fractional)
}

@_transparent
public func frexp<T: BinaryFloatingPoint>(_ x: T) -> (T, Int) {
  guard x.isFinite else { return (x+0, 0) }
  guard x != 0 else { return (x, 0) }
  // The C stdlib `frexp` uses a different notion of significand / exponent
  // than IEEE 754, so we need to adjust them by a factor of two.
  return (x.significand / 2, Int(x.exponent + 1))
}

%for T in ['Float','Double']:
@available(swift, deprecated: 4.2, renamed: "scalbn")
@_transparent
public func ldexp(_ x: ${T}, _ n : Int) -> ${T} {
  return ${T}(sign: .plus, exponent: n, significand: x)
}

%end

//  Floating-point properties that are exposed as functions in the C math
//  library. Mark those function names unavailable and direct users to the
//  properties instead.
@available(*, unavailable, message: "use the floatingPointClass property.")
public func fpclassify<T: FloatingPoint>(_ value: T) -> Int { fatalError() }

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

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

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

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

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

@available(swift, deprecated: 4.2/*, obsoleted: 5.1*/, message: "use the exponent property.")
public func ilogb<T: BinaryFloatingPoint>(_ x: T) -> Int {
  return Int(x.exponent)
}

%{

# Don't need 64-bit (Double/CDouble) overlays. The ordinary C imports work fine.
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 = [
    '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():
%  if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%  end
@_transparent
public func ${ufunc}(_ x: ${T}) -> ${T} {
  return ${T}(${ufunc}${f}(${CT}(x)))
}
%  if T == 'Float80':
#endif
%  end

% end

#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS) || os(visionOS)
// Unary intrinsic functions
// Note these have a corresponding LLVM intrinsic
% for T, ufunc in TypedUnaryIntrinsicFunctions():
%  if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%  end
@_transparent
public func ${ufunc}(_ x: ${T}) -> ${T} {
  return _${ufunc}(x)
}
%  if T == 'Float80':
#endif
%  end

% 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():
%   if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%   end
@_transparent
public func ${ufunc}(_ x: ${T}) -> ${T} {
  return ${T}(${ufunc}${f}(${CT}(x)))
}
%   if T == 'Float80':
#endif
%   end
%  end
% end
#endif

// Binary functions

% for T, CT, f, bfunc in TypedBinaryFunctions():
%  if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%  end
@_transparent
public func ${bfunc}(_ lhs: ${T}, _ rhs: ${T}) -> ${T} {
  return ${T}(${bfunc}${f}(${CT}(lhs), ${CT}(rhs)))
}
%  if T == 'Float80':
#endif
%  end

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the tuple return.
% for T, CT, f in AllFloatTypes():
%  if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || os(OpenBSD) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%  else:
//  lgamma not available on Windows, apparently?
#if !os(Windows)
%  end
@_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))
}
#endif

% end

% # This is AllFloatTypes not OverlayFloatTypes because of the tuple return.
% for T, CT, f in AllFloatTypes():
%  if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%  end
@_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))
}
%  if T == 'Float80':
#endif
%  end

% end

% for T, CT, f in OverlayFloatTypes():
%  if T == 'Float80':
#if (arch(i386) || arch(x86_64)) && !(os(Windows) || os(Android) || ($Embedded && !os(Linux) && !(os(macOS) || os(iOS) || os(watchOS) || os(tvOS))))
%  end
@available(swift, deprecated: 4.2/*, obsoleted: 5.1*/, message:
           "use ${T}(nan: ${T}.RawSignificand).")
@_transparent
@_unavailableInEmbedded
public func nan(_ tag: String) -> ${T} {
  return ${T}(nan${f}(tag))
}
%  if T == 'Float80':
#endif
%  end

% 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: