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Merged
merged 2 commits into from
Jun 7, 2016
Merged

[stdlib] More verbose debugDescription for NaN #2786

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d07baee
[stdlib] More verbose debugDescription for NaNs
rintaro May 12, 2016
702a5ab
[stdlib] Add some tests for NaNs
rintaro Jun 3, 2016
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25 changes: 20 additions & 5 deletions stdlib/public/core/Runtime.swift.gyb
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Original file line number Diff line number Diff line change
Expand Up @@ -350,11 +350,26 @@ func _float${bits}ToStringImpl(

func _float${bits}ToString(_ value: Float${bits}, debug: Bool) -> String {

if value.isInfinite {
return value.sign == .minus ? "-inf" : "inf"
}
if value.isNaN {
return "nan"
if !value.isFinite {
let significand = value.significandBitPattern
if significand == 0 {
// Infinity
return value.sign == .minus ? "-inf" : "inf"
}
else {
// NaN
if !debug {
return "nan"
}
let isSignaling = (significand & Float${bits}._quietNaNMask) == 0
let payload = significand & ((Float${bits}._quietNaNMask >> 1) - 1)
// FIXME(performance): Inefficient String manipulation. We could move
// this to C function.
return
(value.sign == .minus ? "-" : "")
+ (isSignaling ? "snan" : "nan")
+ (payload == 0 ? "" : ("(0x" + String(payload, radix: 16) + ")"))
}
}

_sanityCheck(sizeof(_Buffer32.self) == 32)
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186 changes: 186 additions & 0 deletions test/1_stdlib/FloatingPoint.swift.gyb
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Expand Up @@ -816,6 +816,192 @@ FloatingPoint.test("Float80/Literals") {

#endif

FloatingPoint.test("Float32/quietNaN") {
do {
let f: Float32 = .nan
expectTrue(f.isNaN && !f.isSignalingNaN)
expectEqual(0x7fc0_0000, f.bitPattern)
}
do {
// Empty payload
let f: Float32 = Float32(bitPattern: 0x7fc0_0000)
expectTrue(f.isNaN && !f.isSignalingNaN)
}
do {
// Full payload
let f: Float32 = Float32(bitPattern: 0x7fff_ffff)
expectTrue(f.isNaN && !f.isSignalingNaN)
}
do {
// Highest payload `init(nan:signaling:)` can handle
let f: Float32 = Float32(nan: 0x1f_ffff, signaling: false)
expectTrue(f.isNaN && !f.isSignalingNaN)
expectEqual(0x7fdf_ffff, f.bitPattern)
}
do {
// Payload overflow
expectCrashLater()
_ = Float32(nan: 0x20_0000, signaling: false)
}
}

FloatingPoint.test("Float64/quietNaN") {
do {
let f: Float64 = .nan
expectTrue(f.isNaN && !f.isSignalingNaN)
expectEqual(0x7ff8_0000_0000_0000, f.bitPattern)
}
do {
// Empty payload
let f: Float64 = Float64(bitPattern: 0x7ff8_0000_0000_0000)
expectTrue(f.isNaN && !f.isSignalingNaN)
}
do {
// Full payload
let f: Float64 = Float64(bitPattern: 0x7fff_ffff_ffff_ffff)
expectTrue(f.isNaN && !f.isSignalingNaN)
}
do {
// Highest payload `init(nan:signaling:)` can handle
let f: Float64 = Float64(nan: 0x3_ffff_ffff_ffff, signaling: false)
expectTrue(f.isNaN && !f.isSignalingNaN)
expectEqual(0x7ffb_ffff_ffff_ffff, f.bitPattern)
}
do {
// Payload overflow
expectCrashLater()
_ = Float64(nan: 0x4_0000_0000_0000, signaling: false)
}
}

#if arch(i386) || arch(x86_64)

FloatingPoint.test("Float80/quietNaN") {
do {
let f: Float80 = .nan
expectTrue(f.isNaN && !f.isSignalingNaN)
expectEqual(Float80Bits(0x7fff, 0xc000_0000_0000_0000), f.bitPattern)
}
do {
// Empty payload
let f: Float80 = Float80(bitPattern: Float80Bits(0x7fff, 0xc000_0000_0000_0000))
expectTrue(f.isNaN && !f.isSignalingNaN)
}
do {
// Full payload
let f: Float80 = Float80(bitPattern: Float80Bits(0x7fff, 0xffff_ffff_ffff_ffff))
expectTrue(f.isNaN && !f.isSignalingNaN)
}
do {
// Highest payload `init(nan:signaling:)` can handle
let f: Float80 = Float80(nan: 0x1fff_ffff_ffff_ffff, signaling: false)
expectTrue(f.isNaN && !f.isSignalingNaN)
expectEqual(Float80Bits(0x7fff, 0xdfff_ffff_ffff_ffff), f.bitPattern)
}
do {
// Payload overflow
expectCrashLater()
_ = Float80(nan: 0x2000_0000_0000_0000, signaling: false)
}
}

#endif

#if !arch(i386)

FloatingPoint.test("Float32/signalingNaN") {
do {
let f: Float32 = .signalingNaN
expectTrue(f.isNaN && f.isSignalingNaN)
expectEqual(0x7fa0_0000, f.bitPattern)
}
do {
// Empty payload
let f: Float32 = Float32(bitPattern: 0x7fa0_0000)
expectTrue(f.isNaN && f.isSignalingNaN)
}
do {
// Full payload
let f: Float32 = Float32(bitPattern: 0x7fbf_ffff)
expectTrue(f.isNaN && f.isSignalingNaN)
}
do {
// Highest payload `init(nan:signaling:)` can handle
let f: Float32 = Float32(nan: 0x1f_ffff, signaling: true)
expectTrue(f.isNaN && f.isSignalingNaN)
expectEqual(0x7fbf_ffff, f.bitPattern)
}
do {
// payload overflow
expectCrashLater()
_ = Float32(nan: 0x20_0000, signaling: true)
}
}

FloatingPoint.test("Float64/signalingNaN") {
do {
let f: Float64 = .signalingNaN
expectTrue(f.isNaN && f.isSignalingNaN)
expectEqual(0x7ff4_0000_0000_0000, f.bitPattern)
}
do {
// Empty payload
let f: Float64 = Float64(bitPattern: 0x7ff4_0000_0000_0000)
expectTrue(f.isNaN && f.isSignalingNaN)
}
do {
// Full payload
let f: Float64 = Float64(bitPattern: 0x7ff7_ffff_ffff_ffff)
expectTrue(f.isNaN && f.isSignalingNaN)
}
do {
// Highest payload `init(nan:signaling:)` can handle
let f: Float64 = Float64(nan: 0x3_ffff_ffff_ffff, signaling: true)
expectTrue(f.isNaN && f.isSignalingNaN)
expectEqual(0x7ff7_ffff_ffff_ffff, f.bitPattern)
}
do {
// payload overflow
expectCrashLater()
_ = Float64(nan: 0x4_0000_0000_0000, signaling: true)
}
}

#endif

#if arch(i386) || arch(x86_64)

FloatingPoint.test("Float80/signalingNaN") {
do {
let f: Float80 = .signalingNaN
expectTrue(f.isNaN && f.isSignalingNaN)
expectEqual(Float80Bits(0x7fff, 0xa000_0000_0000_0000), f.bitPattern)
}
do {
// Empty payload
let f: Float80 = Float80(bitPattern: Float80Bits(0x7fff, 0xa000_0000_0000_0000))
expectTrue(f.isNaN && f.isSignalingNaN)
}
do {
// Full payload
let f: Float80 = Float80(bitPattern: Float80Bits(0x7fff, 0xbfff_ffff_ffff_ffff))
expectTrue(f.isNaN && f.isSignalingNaN)
}
do {
// Highest payload `init(nan:signaling:)` can handle
let f: Float80 = Float80(nan: 0x1fff_ffff_ffff_ffff, signaling: true)
expectTrue(f.isNaN && f.isSignalingNaN)
expectEqual(Float80Bits(0x7fff, 0xbfff_ffff_ffff_ffff), f.bitPattern)
}
do {
// payload overflow
expectCrashLater()
_ = Float80(nan: 0x2000_0000_0000_0000, signaling: true)
}
}

#endif

var FloatingPointClassification = TestSuite("NumericParsing")

FloatingPointClassification.test("FloatingPointClassification/Equatable") {
Expand Down
58 changes: 58 additions & 0 deletions test/1_stdlib/PrintFloat.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -56,6 +56,8 @@ PrintTests.test("Printable") {
expectPrinted("-inf", -Float.infinity)
expectPrinted("nan", Float.nan)
expectPrinted("nan", -Float.nan)
expectPrinted("nan", Float.signalingNaN)
expectPrinted("nan", -Float.signalingNaN)
expectPrinted("0.0", asFloat32(0.0))
expectPrinted("1.0", asFloat32(1.0))
expectPrinted("-1.0", asFloat32(-1.0))
Expand All @@ -66,12 +68,28 @@ PrintTests.test("Printable") {
expectPrinted("-inf", -Double.infinity)
expectPrinted("nan", Double.nan)
expectPrinted("nan", -Double.nan)
expectPrinted("nan", Double.signalingNaN)
expectPrinted("nan", -Double.signalingNaN)
expectPrinted("0.0", asFloat64(0.0))
expectPrinted("1.0", asFloat64(1.0))
expectPrinted("-1.0", asFloat64(-1.0))
expectPrinted("100.125", asFloat64(100.125))
expectPrinted("-100.125", asFloat64(-100.125))

#if arch(i386) || arch(x86_64)
expectPrinted("inf", Float80.infinity)
expectPrinted("-inf", -Float80.infinity)
expectPrinted("nan", Float80.nan)
expectPrinted("nan", -Float80.nan)
expectPrinted("nan", Float80.signalingNaN)
expectPrinted("nan", -Float80.signalingNaN)
expectPrinted("0.0", asFloat80(0.0))
expectPrinted("1.0", asFloat80(1.0))
expectPrinted("-1.0", asFloat80(-1.0))
expectPrinted("100.125", asFloat80(100.125))
expectPrinted("-100.125", asFloat80(-100.125))
#endif

expectPrinted("1.00001", asFloat32(1.00001))
expectPrinted("1.25e+17", asFloat32(125000000000000000.0))
expectPrinted("1.25e+16", asFloat32(12500000000000000.0))
Expand Down Expand Up @@ -191,17 +209,57 @@ PrintTests.test("Printable") {
expectDebugPrinted("1.24999998e+17", asFloat32(125000000000000000.0))
expectDebugPrinted("1.25", asFloat32(1.25))
expectDebugPrinted("1.24999997e-05", asFloat32(0.0000125))
expectDebugPrinted("inf", Float.infinity)
expectDebugPrinted("-inf", -Float.infinity)
expectDebugPrinted("nan", Float.nan)
expectDebugPrinted("-nan", -Float.nan)
expectDebugPrinted("nan(0xffff)", Float(nan: 65535, signaling: false))
expectDebugPrinted("-nan(0xffff)", -Float(nan: 65535, signaling: false))
expectDebugPrinted("nan(0x1fffff)", Float(bitPattern: 0x7fff_ffff))
expectDebugPrinted("nan(0x1fffff)", Float(bitPattern: 0x7fdf_ffff))
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@rintaro rintaro Jun 3, 2016 •
edited
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Actually, current implementation drops MSB of payload bits,
because that bit is reserved for placeholder payload of signaling NaN.
I'm not sure whether this behavior is reasonable or not. @stephentyrone ?

#if !arch(i386)
expectDebugPrinted("snan", Float.signalingNaN)
expectDebugPrinted("snan(0xffff)", Float(nan: 65535, signaling: true))
expectDebugPrinted("-snan(0xffff)", -Float(nan: 65535, signaling: true))
expectDebugPrinted("snan(0x1fffff)", Float(bitPattern: 0x7fbf_ffff))
#endif

expectDebugPrinted("1.1000000000000001", asFloat64(1.1))
expectDebugPrinted("1.25e+17", asFloat64(125000000000000000.0))
expectDebugPrinted("1.25", asFloat64(1.25))
expectDebugPrinted("1.2500000000000001e-05", asFloat64(0.0000125))
expectDebugPrinted("inf", Double.infinity)
expectDebugPrinted("-inf", -Double.infinity)
expectDebugPrinted("nan", Double.nan)
expectDebugPrinted("-nan", -Double.nan)
expectDebugPrinted("nan(0xffff)", Double(nan: 65535, signaling: false))
expectDebugPrinted("-nan(0xffff)", -Double(nan: 65535, signaling: false))
expectDebugPrinted("nan(0x3ffffffffffff)", Float64(bitPattern: 0x7fff_ffff_ffff_ffff))
expectDebugPrinted("nan(0x3ffffffffffff)", Float64(bitPattern: 0x7ffb_ffff_ffff_ffff))
#if !arch(i386)
expectDebugPrinted("snan", Double.signalingNaN)
expectDebugPrinted("snan(0xffff)", Double(nan: 65535, signaling: true))
expectDebugPrinted("-snan(0xffff)", -Double(nan: 65535, signaling: true))
expectDebugPrinted("snan(0x3ffffffffffff)", Float64(bitPattern: 0x7ff7_ffff_ffff_ffff))
#endif

#if arch(i386) || arch(x86_64)
expectDebugPrinted("1.10000000000000000002", asFloat80(1.1))
expectDebugPrinted("125000000000000000.0", asFloat80(125000000000000000.0))
expectDebugPrinted("1.25", asFloat80(1.25))
expectDebugPrinted("1.25000000000000000001e-05", asFloat80(0.0000125))
expectDebugPrinted("inf", Float80.infinity)
expectDebugPrinted("-inf", -Float80.infinity)
expectDebugPrinted("nan", Float80.nan)
expectDebugPrinted("-nan", -Float80.nan)
expectDebugPrinted("nan(0xffff)", Float80(nan: 65535, signaling: false))
expectDebugPrinted("-nan(0xffff)", -Float80(nan: 65535, signaling: false))
expectDebugPrinted("nan(0x1fffffffffffffff)", Float80(sign: .plus, exponentBitPattern: 0x7fff, significandBitPattern: 0xffff_ffff_ffff_ffff))
expectDebugPrinted("nan(0x1fffffffffffffff)", Float80(sign: .plus, exponentBitPattern: 0x7fff, significandBitPattern: 0xdfff_ffff_ffff_ffff))
expectDebugPrinted("snan", Float80.signalingNaN)
expectDebugPrinted("snan(0xffff)", Float80(nan: 65535, signaling: true))
expectDebugPrinted("-snan(0xffff)", -Float80(nan: 65535, signaling: true))
expectDebugPrinted("snan(0x1fffffffffffffff)", Float80(sign: .plus, exponentBitPattern: 0x7fff, significandBitPattern: 0xbfff_ffff_ffff_ffff))
#endif
}

Expand Down