Fix sign bit shift

Author: natecook1000

Tests/BinaryParsingTests/FloatingPointTests.swift

@@ -200,21 +200,22 @@ struct FloatingPointTests {
     let bytesBE = Array(bigEndian: value)
 
     do {
-      let value1 = try bytesLE.withParserSpan(Float80.init(parsingLittleEndian:))
+      let value1 = try bytesLE.withParserSpan(
+        Float80.init(parsingLittleEndian:))
       let value2 = try bytesLE.withParserSpan { input in
         try Float80(parsing: &input, endianness: .little)
       }
 
       if value.isNaN {
-        #expect(value1.isNaN)
-        #expect(value2.isNaN)
+        #expect(value1.isNaN, "little")
+        #expect(value2.isNaN, "little")
         if value.isSignalingNaN {
           #expect(value1.isSignalingNaN)
           #expect(value2.isSignalingNaN)
         }
       } else {
-        #expect(value1 == value)
-        #expect(value2 == value)
+        #expect(value1 == value, "little")
+        #expect(value2 == value, "little")
       }
     }
 
@@ -225,15 +226,15 @@ struct FloatingPointTests {
       }
 
       if value.isNaN {
-        #expect(value1.isNaN)
-        #expect(value2.isNaN)
+        #expect(value1.isNaN, "big")
+        #expect(value2.isNaN, "big")
         if value.isSignalingNaN {
           #expect(value1.isSignalingNaN)
           #expect(value2.isSignalingNaN)
         }
       } else {
-        #expect(value1 == value)
-        #expect(value2 == value)
+        #expect(value1 == value, "big")
+        #expect(value2 == value, "big")
       }
     }
 

Tests/BinaryParsingTests/TestingSupport.swift

@@ -146,7 +146,7 @@ extension Array where Element == UInt8 {
       self.append(contentsOf: bytes)
     }
     let signAndExponent =
-      value.exponentBitPattern | (value.sign == .minus ? 1 : 0 << 31)
+      value.exponentBitPattern | ((value.sign == .minus ? 1 : 0) << 15)
     Swift.withUnsafeBytes(of: signAndExponent.littleEndian) { bytes in
       self.append(contentsOf: bytes)
     }
@@ -155,7 +155,7 @@ extension Array where Element == UInt8 {
   init(bigEndian value: Float80) {
     self = []
     let signAndExponent =
-      value.exponentBitPattern | (value.sign == .minus ? 1 : 0 << 31)
+      value.exponentBitPattern & 0x7FFF | ((value.sign == .minus ? 1 : 0) << 15)
     Swift.withUnsafeBytes(of: signAndExponent.bigEndian) { bytes in
       self.append(contentsOf: bytes)
     }