swift-mirror/stdlib/core/FloatingPoint.swift.gyb

@# -*- mode: swift -*-

@# Ignore the following admonition; it applies to the resulting .swift file only
//// Automatically Generated From FloatingPoint.gyb.  Do Not Edit Directly
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

@{
#
# Utility code for later in this template
#

if CMAKE_SYSTEM_PROCESSOR in ('i386', 'x86_64'):
  allFloatBits = [32, 64, 80]
else:
  # Compile only 32-bit and 64-bit floating point on non-x86 architectures
  allFloatBits = [32, 64]

# Bit counts for all int types
allIntBits = [8, 16, 32, 64, 'Int']

# Number of bits in integer literals.
builtinIntLiteralBits = 2048

# Number of bits in floating point literals.
builtinFloatLiteralBits = 64

def allInts():
    for bits in allIntBits:
        for signed in False, True:
            yield bits,signed

def baseIntName(name):
    return 'Int' if name == 'Int' else 'Int' + str(name)

def builtinIntName(name):
    return 'Word' if name == 'Int' else 'Int' + str(name)

def intName(name, signed):
    return ('' if signed else 'U') + baseIntName(name)

def floatName(bits):
    return 'Float' + str(bits)

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

def llvmIntrinsicSuffix(bits):
    if bits == 32:
        return 'f32'
    if bits == 64:
        return 'f64'
    if bits == 80:
        return 'f80'

def getInfBitPattern(bits):
    if bits == 32:
        return '0x7f800000'
    if bits == 64:
        return '0x7ff0000000000000'
    return 'error'

def getQuietNaNBitPattern(bits):
    if bits == 32:
        return '0x7fc00000'
    if bits == 64:
        return '0x7ff8000000000000'
    return 'error'

def getSignalingNanBitPattern(bits):
    if bits == 32:
        return '0x7fa00000'
    if bits == 64:
        return '0x7ff4000000000000'
    return 'error'

def getMinNormalBitPattern(bits):
    if bits == 32:
        return '0x00800000'
    if bits == 64:
        return '0x0010000000000000'
    return 'error'

def getExponentBitCount(bits):
    if bits == 32:
        return '8'
    if bits == 64:
        return '11'
    return 'error'

def getSignificantBitCount(bits):
    if bits == 32:
        return '23'
    if bits == 64:
        return '52'
    return 'error'

def getInfinityExponent(bits):
    if bits == 32:
        return '0xff'
    if bits == 64:
        return '0x7ff'
    return 'error'

}@

@ for bits in allFloatBits:
@   Self = floatName(bits)

struct ${Self} : ReplPrintable {
  var value: Builtin.FPIEEE${bits}

  @@transparent
  init() {
    var zero: Int64 = 0
    value = Builtin.uitofp_Int64_FPIEEE${bits}(zero.value)
  }

  @@transparent
  init(v: Builtin.FPIEEE${bits}) {
    value = v
  }

  func replPrint() {
@if bits == 64:
    print(self)
@else:
    print(Double(self))
@end
  }
}

@ if bits in allIntBits:
// Not transparent because the compiler crashes in that case.
//@@transparent
extension ${Self} : FloatingPointNumber {
  typealias _BitsType = UInt${bits}

  static func _fromBitPattern(bits: _BitsType) -> ${Self} {
    return ${Self}(Builtin.bitcast_Int${bits}_FPIEEE${bits}(bits.value))
  }

  func _toBitPattern() -> _BitsType {
    return _BitsType(Builtin.bitcast_FPIEEE${bits}_Int${bits}(value))
  }

  func __getSignBit() -> Int {
    return Int(_toBitPattern() >> ${bits - 1}) & 1
  }

  func __getBiasedExponent() -> _BitsType {
    return (_toBitPattern() >> ${getSignificantBitCount(bits)}) & ${getInfinityExponent(bits)}
  }

  func __getSignificand() -> _BitsType {
    var mask: _BitsType = (1 << ${getSignificantBitCount(bits)}) - 1
    return _toBitPattern() & mask
  }

  static func inf() -> ${Self} {
    return _fromBitPattern(${getInfBitPattern(bits)})
  }

  static func NaN() -> ${Self} {
    return quietNaN()
  }

  static func quietNaN() -> ${Self} {
    return _fromBitPattern(${getQuietNaNBitPattern(bits)})
  }

  func isSignMinus() -> Bool {
    return __getSignBit() == 1
  }

  func isNormal() -> Bool {
    var biasedExponent = __getBiasedExponent()
    return biasedExponent != ${getInfinityExponent(bits)} &&
           biasedExponent != 0
  }

  func isFinite() -> Bool {
    return __getBiasedExponent() != ${getInfinityExponent(bits)}
  }

  func isZero() -> Bool {
    // Mask out the sign bit.
    var mask: _BitsType = (1 << (${bits} - 1)) - 1
    return (_toBitPattern() & mask) == 0
  }

  func isSubnormal() -> Bool {
    if __getBiasedExponent() == 0 {
      return __getSignificand() != 0
    }
    return false

    // Alternative implementation:
    // return !isNan() &&
    //     abs(self) < ${Self}._fromBitPattern(${getMinNormalBitPattern(bits)})
    //
    // But because we need to check for !isNan(), and do it safely in case of
    // SNaN, we need to go down to the bit level, so open-coding the combined
    // condition is going to be faster.
  }

  func isInfinite() -> Bool {
    if __getBiasedExponent() == ${getInfinityExponent(bits)} {
      return __getSignificand() == 0
    }
    return false

    // Alternative implementation that is not safe in case of SNaN:
    // return abs(self) == ${Self}.inf()
  }

  func isNaN() -> Bool {
    if __getBiasedExponent() == ${getInfinityExponent(bits)} {
      return __getSignificand() != 0
    }
    return false

    // Alternative implementation that is not safe in case of SNaN:
    // return self != self
  }

  func isSignaling() -> Bool {
    if __getBiasedExponent() == ${getInfinityExponent(bits)} {
      // IEEE-754R 2008 6.2.1: A signaling NaN bit string should be encoded
      // with the first bit of the trailing significand being 0.  If the first
      // bit of the trailing significand field is 0, some other bit of the
      // trailing significand field must be non-zero to distinguish the NaN
      // from infinity.
      var significand = __getSignificand()
      if significand != 0 {
        return (significand >> (${getSignificantBitCount(bits)} - 1)) == 0
      }
    }
    return false
  }
}

// Not @transparent because the function is too complex.
extension ${Self} /* : FloatingPointNumber */ {
  var floatingPointClass: FloatingPointClassification {
    get {
      var biasedExponent = __getBiasedExponent()
      if biasedExponent == ${getInfinityExponent(bits)} {
        var significand = __getSignificand()
        // This is either +/-inf or NaN.
        if significand == 0 {
          return isSignMinus() ? .NegativeInfinity : .PositiveInfinity
        }
        var isQNaN = (significand >> (${getSignificantBitCount(bits)} - 1)) == 1
        return isQNaN ? .QuietNaN : .SignalingNaN
      }

      // OK, the number is finite.
      var isMinus = isSignMinus()
      if biasedExponent != 0 {
        return isMinus ? .NegativeNormal : .PositiveNormal
      }

      // Exponent is zero.
      if __getSignificand() == 0 {
        return isMinus ? .NegativeZero : .PositiveZero
      }
      return isMinus ? .NegativeSubnormal : .PositiveSubnormal
    }
  }
}
@ end

@@transparent
extension ${Self} : BuiltinIntegerLiteralConvertible, IntegerLiteralConvertible {
  static func _convertFromBuiltinIntegerLiteral(value: Builtin.Int${builtinIntLiteralBits}) -> ${Self} {
    return ${Self}(Builtin.itofp_with_overflow_Int${builtinIntLiteralBits}_FPIEEE${bits}(value))
  }

  static func convertFromIntegerLiteral(value: Int64) -> ${Self} {
    return ${Self}(Builtin.uitofp_Int64_FPIEEE${bits}(value.value))
  }
}

@@transparent
extension ${Self} : BuiltinFloatLiteralConvertible {
  static func _convertFromBuiltinFloatLiteral(value: Builtin.FPIEEE${builtinFloatLiteralBits}) -> ${Self} {
@   if bits == builtinFloatLiteralBits:
    return ${Self}(value)
@   elif bits < builtinFloatLiteralBits:
    return ${Self}(Builtin.fptrunc_FPIEEE${builtinFloatLiteralBits}_FPIEEE${bits}(value))
@   else:
    // FIXME: This is actually losing precision <rdar://problem/14073102>.
    return ${Self}(Builtin.fpext_FPIEEE${builtinFloatLiteralBits}_FPIEEE${bits}(value))
@   end
  }
}

@@transparent
extension ${Self} : FloatLiteralConvertible {
  static func convertFromFloatLiteral(value: ${Self}) -> ${Self} {
    return value
  }
}

@@transparent
func ==(lhs: ${Self}, rhs: ${Self}) -> Bool {
  return Bool(Builtin.fcmp_oeq_FPIEEE${bits}(lhs.value, rhs.value))
}

@@transparent
func <(lhs: ${Self}, rhs: ${Self}) -> Bool {
  return Bool(Builtin.fcmp_olt_FPIEEE${bits}(lhs.value, rhs.value))
}

@@transparent
extension ${Self} : Comparable {
}

extension ${Self} : Hashable {
  func hashValue() -> Int {
    var asBuiltinInt = Builtin.bitcast_FPIEEE${bits}_Int${bits}(value)
@   if bits >= 64:
    return Int(Builtin.truncOrBitCast_Int${bits}_Word(asBuiltinInt))
@   elif bits <= 32:
    return Int(Builtin.sextOrBitCast_Int${bits}_Word(asBuiltinInt))
@   else:
    error unhandled float size ${bits}
@   end
  }
}

extension ${Self} : SignedNumber {
  @@transparent
  static func negate(rhs: ${Self}) -> (${Self}, Bool) {
    return (${Self}(Builtin.fneg_FPIEEE${bits}(rhs.value)), false)
  }
  @@transparent
  static func abs(rhs: ${Self}) -> (${Self}, Bool) {
    return (${Self}(Builtin.int_fabs_FPIEEE${bits}(rhs.value)), false)
  }
  @@transparent
  func isNegative() -> Bool { return self < 0 }
}

//===----------------------------------------------------------------------===//
// Explicit conversions between types.
//===----------------------------------------------------------------------===//

// Construction from integers.
@@transparent
extension ${Self} {
@ for (srcBits, srcSigned) in allInts():
@    That = intName(srcBits, srcSigned)
@    ThatBuiltinName = builtinIntName(srcBits)
@    sign = 's' if srcSigned else 'u'
  init(v: ${That}) {
    value = Builtin.${sign}itofp_${ThatBuiltinName}_FPIEEE${bits}(v.value)
  }
@ end
}

// Construction from other floating point numbers.
@@transparent
extension ${Self} {
@ for srcBits in allFloatBits:
@   That = floatName(srcBits)
@   if Self != That:
  init(v: ${That}) {
@     if srcBits > bits:
  value = Builtin.fptrunc_FPIEEE${srcBits}_FPIEEE${bits}(v.value)
@     else:
  value = Builtin.fpext_FPIEEE${srcBits}_FPIEEE${bits}(v.value)
@     end
  }
@   end
@ end
}

//===----------------------------------------------------------------------===//
// Standard Operator Table
//===----------------------------------------------------------------------===//

// Unary plus
@@transparent @@prefix
func + (rhs: ${Self}) -> ${Self} { return rhs }

@@transparent @@prefix @@assignment
func ++ (inout rhs: ${Self}) -> ${Self} { rhs += 1.0; return rhs }
@@transparent @@prefix @@assignment
func -- (inout rhs: ${Self}) -> ${Self} { rhs -= 1.0; return rhs }
@@transparent @@postfix @@assignment
func ++ (inout lhs: ${Self}) -> ${Self} { let tmp = lhs; lhs += 1.0; return tmp }
@@transparent @@postfix @@assignment
func -- (inout lhs: ${Self}) -> ${Self} { let tmp = lhs; lhs -= 1.0; return tmp }

@ for op, name in ('+','fadd'), ('-','fsub'),('*','fmul'), ('/','fdiv'):
@@transparent
func ${op} (lhs: ${Self}, rhs: ${Self}) -> ${Self} {
  return ${Self}(Builtin.${name}_FPIEEE${bits}(lhs.value, rhs.value))
}
@ end

// Binary Remainder.
// The sign of the result matches the sign of the dividend.
// 1) This is consistent with '%' in C#, D, Java, and JavaScript
// 2) C99 requires this behavior for fmod*()
// 3) C++11 requires this behavior for std::fmod*()
@@asmname="fmod${cFuncSuffix(bits)}"
func % (lhs: ${Self}, rhs: ${Self}) -> ${Self}

// See Bool.swift for && and ||
// In C, 120 is &&
// In C, 110 is ||

// In C, 100 is ?:
// In C, 90 is =, *=, += etc.

@ for op in '+', '-', '*', '/', '%':
@@transparent @@assignment
func ${op}= (inout lhs: ${Self}, rhs: ${Self}) { lhs = lhs ${op} rhs }
@ end

@ end # for bits in allFloatBits

// Construction of integers from floating point numbers.
@ for (bits, signed) in allInts():
@   sign = 's' if signed else 'u'
@   Self = intName(bits, signed)
@   BuiltinName = builtinIntName(bits)
@@transparent
extension ${Self} {
@   for srcBits in allFloatBits:
@     That = floatName(srcBits)
  init(v: ${That}) {
    value = Builtin.fpto${sign}i_FPIEEE${srcBits}_${BuiltinName}(v.value)
  }
@   end
}

@ end