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small optimization

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This commit is contained in:
Jeff Hill
2001-05-22 23:35:23 +00:00
parent 6d5a8b94a6
commit 48aa0b3e45
1 changed files with 19 additions and 22 deletions
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41
src/libCom/osi/os/default/osiWireFormat.h
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@@ -28,20 +28,17 @@
// this endian test will hopefully vanish during optimization
// and therefore be executed only at compile time
inline bool osiLittleEndian ()
{
union {
epicsUInt32 uint;
epicsUInt8 uchar[4];
} osiWireFormatEndianTest;
osiWireFormatEndianTest.uint = 1;
if ( osiWireFormatEndianTest.uchar[0] == 1 ) {
return true;
}
else {
return false;
}
}
union endianTest {
public:
endianTest () : uint ( 1u ) {}
bool littleEndian () const { return uchar[0] & 1u; }
bool bigEndian () const { return ! littleEndian(); }
private:
unsigned uint;
unsigned char uchar[4];
};
static const endianTest endianTester;
inline void osiConvertToWireFormat ( const epicsFloat32 &value, epicsUInt8 *pWire )
{
@@ -50,10 +47,10 @@ inline void osiConvertToWireFormat ( const epicsFloat32 &value, epicsUInt8 *pWir
epicsFloat32 ftmp;
};
ftmp = value;
pWire[0] = static_cast < unsigned char > ( utmp >> 24u );
pWire[1] = static_cast < unsigned char > ( utmp >> 16u );
pWire[2] = static_cast < unsigned char > ( utmp >> 8u );
pWire[3] = static_cast < unsigned char > ( utmp >> 0u );
pWire[0] = static_cast < epicsUInt8 > ( utmp >> 24u );
pWire[1] = static_cast < epicsUInt8 > ( utmp >> 16u );
pWire[2] = static_cast < epicsUInt8 > ( utmp >> 8u );
pWire[3] = static_cast < epicsUInt8 > ( utmp >> 0u );
}
inline void osiConvertToWireFormat ( const epicsFloat64 &value, epicsUInt8 *pWire )
@@ -64,7 +61,7 @@ inline void osiConvertToWireFormat ( const epicsFloat64 &value, epicsUInt8 *pWir
};
ftmp = value;
// this endian test should vanish during optimization
if ( osiLittleEndian () ) {
if ( endianTester.littleEndian () ) {
// little endian
pWire[0] = btmp[7];
pWire[1] = btmp[6];
@@ -88,7 +85,7 @@ inline void osiConvertToWireFormat ( const epicsFloat64 &value, epicsUInt8 *pWir
}
}
inline void osiConvertFromWireFormat ( epicsFloat32 &value, epicsUInt8 *pWire )
inline void osiConvertFromWireFormat ( epicsFloat32 &value, const epicsUInt8 *pWire )
{
union {
epicsUInt32 utmp;
@@ -101,13 +98,13 @@ inline void osiConvertFromWireFormat ( epicsFloat32 &value, epicsUInt8 *pWire )
value = ftmp;
}
inline void osiConvertFromWireFormat ( epicsFloat64 &value, epicsUInt8 *pWire )
inline void osiConvertFromWireFormat ( epicsFloat64 &value, const epicsUInt8 *pWire )
{
union {
epicsUInt8 btmp[8];
epicsFloat64 ftmp;
};
if ( osiLittleEndian () ) {
if ( endianTester.littleEndian () ) {
btmp[7] = pWire[0];
btmp[6] = pWire[1];
btmp[5] = pWire[2];