Spin : Unsigned Longs
hippy
Posts: 1,981
To save re-inventing the wheel, a wad of testing, debugging and proving, does anyone have any code already written to handle unsigned long variables ...
* To add two numbers with overflow detected
* To subtract two numbers with underflow detected
* To compare two numbers
I've got a set of compare routines but cannot help thinking there must be a better way to do it ...
Post Edited (hippy) : 11/12/2007 4:57:59 PM GMT
* To add two numbers with overflow detected
* To subtract two numbers with underflow detected
* To compare two numbers
I've got a set of compare routines but cannot help thinking there must be a better way to do it ...
CON
LT = %100
EQ = %010
GT = %001
LE = %110
NE = %101
GE = %011
PRI CompareUnsigned( lhs, rhs )
if lhs == rhs ' lhs rhs
result := EQ ' ??? ??? => lhs EQ rhs
else
if lhs => 0
if rhs => 0
if lhs > rhs
result := GT ' +Ve +Ve => lhs GT rhs
else
result := LT ' +Ve +Ve => lhs LT rhs
else
result := LT ' +Ve -Ve => lhs LT rhs
else
if rhs => 0
result := GT ' -Ve +Ve => lhs GT rhs
else
if lhs > rhs
result := GT ' -Ve -Ve => lhs GT rhs
else
result := LT ' -Ve -Ve => lhs LT rhs
PRI IsUnsignedLt( lhs, rhs )
result := CompareUnsigned(lhs,rhs) == LT
PRI IsUnsignedEq( lhs, rhs )
result := lhs == rhs
PRI IsUnsignedGt( lhs, rhs )
result := CompareUnsigned(lhs,rhs) == GT
PRI IsUnsignedLe( lhs, rhs )
result := ( CompareUnsigned(lhs,rhs) & LE ) <> 0
PRI IsUnsignedNe( lhs, rhs )
result := lhs <> rhs
PRI IsUnsignedGe( lhs, rhs )
result := ( CompareUnsigned(lhs,rhs) & GE ) <> 0
Post Edited (hippy) : 11/12/2007 4:57:59 PM GMT