add math.gcd()

docs/source/_static/symboldumps/skeletons-c128.txt

@@ -240,6 +240,7 @@ math  {
     direction  (ubyte x1, ubyte y1, ubyte x2, ubyte y2) -> ubyte 
     direction_qd  (ubyte quadrant @A, ubyte xdelta @X, ubyte ydelta @Y) -> ubyte @A 
     direction_sc  (byte x1, byte y1, byte x2, byte y2) -> ubyte 
+    gcd  (uword a, uword b) -> uword 
     interpolate  (ubyte v, ubyte inputMin, ubyte inputMax, ubyte outputMin, ubyte outputMax) -> ubyte 
     lerp  (ubyte v0, ubyte v1, ubyte t) -> ubyte 
     lerpw  (uword v0, uword v1, uword t) -> uword 

docs/source/_static/symboldumps/skeletons-c64.txt

@@ -369,6 +369,7 @@ math  {
     direction  (ubyte x1, ubyte y1, ubyte x2, ubyte y2) -> ubyte 
     direction_qd  (ubyte quadrant @A, ubyte xdelta @X, ubyte ydelta @Y) -> ubyte @A 
     direction_sc  (byte x1, byte y1, byte x2, byte y2) -> ubyte 
+    gcd  (uword a, uword b) -> uword 
     interpolate  (ubyte v, ubyte inputMin, ubyte inputMax, ubyte outputMin, ubyte outputMax) -> ubyte 
     interpolatef   alias for: floats.interpolate
     lerp  (ubyte v0, ubyte v1, ubyte t) -> ubyte 

docs/source/_static/symboldumps/skeletons-cx16.txt

@@ -545,6 +545,7 @@ math  {
     direction  (ubyte x1, ubyte y1, ubyte x2, ubyte y2) -> ubyte 
     direction_qd  (ubyte quadrant @A, ubyte xdelta @X, ubyte ydelta @Y) -> ubyte @A 
     direction_sc  (byte x1, byte y1, byte x2, byte y2) -> ubyte 
+    gcd  (uword a, uword b) -> uword 
     interpolate  (ubyte v, ubyte inputMin, ubyte inputMax, ubyte outputMin, ubyte outputMax) -> ubyte 
     interpolatef   alias for: floats.interpolate
     lerp  (ubyte v0, ubyte v1, ubyte t) -> ubyte 

docs/source/_static/symboldumps/skeletons-pet32.txt

@@ -294,6 +294,7 @@ math  {
     direction  (ubyte x1, ubyte y1, ubyte x2, ubyte y2) -> ubyte 
     direction_qd  (ubyte quadrant @A, ubyte xdelta @X, ubyte ydelta @Y) -> ubyte @A 
     direction_sc  (byte x1, byte y1, byte x2, byte y2) -> ubyte 
+    gcd  (uword a, uword b) -> uword 
     interpolate  (ubyte v, ubyte inputMin, ubyte inputMax, ubyte outputMin, ubyte outputMax) -> ubyte 
     interpolatef   alias for: floats.interpolate
     lerp  (ubyte v0, ubyte v1, ubyte t) -> ubyte 

docs/source/_static/symboldumps/skeletons-virtual.txt

@@ -228,6 +228,7 @@ math  {
     direction  (ubyte x1, ubyte y1, ubyte x2, ubyte y2) -> ubyte 
     direction_qd  (ubyte quadrant, ubyte xdelta, ubyte ydelta) -> ubyte 
     direction_sc  (byte x1, byte y1, byte x2, byte y2) -> ubyte 
+    gcd  (uword aa, uword bb) -> uword 
     interpolate  (ubyte v, ubyte inputMin, ubyte inputMax, ubyte outputMin, ubyte outputMax) -> ubyte 
     lerp  (ubyte v0, ubyte v1, ubyte t) -> ubyte 
     lerpf   alias for: floats.lerp

docs/source/libraries.rst

@@ -65,6 +65,10 @@ divmod (dividend, divisor, quotient, remainder)
     All values are ubytes or all are uwords.
     The last two arguments must be variables to receive the quotient and remainder results, respectively.
 
+gcd (a, b)
+    Returns the GCD (greatest common divisor) of uwords a and b
+    The routine is efficient and uses bit shifts instead of divisions.
+
 max (x, y)
     Returns the largest of x and y. Supported for integer types only, for floats use ``floats.maxf()`` instead.
 

docs/source/todo.rst

@@ -10,6 +10,7 @@ Weird Heisenbug
 
 Future Things and Ideas
 ^^^^^^^^^^^^^^^^^^^^^^^
+- add a -warnimplicitcasts and -warnexplicitcasts?
 - make builtin functions capable of returning multiple values, then make divmod() return the 2 results rather than accepting 2 extra variables as arguments
 - then also introduce lmh(longvalue) -or whatever sensible name- builtin function that returns the low, mid, hi (bank) bytes of a long.
 - add a -profile option (for now X16 only) that instruments the start (and returns?) -of every prog8 subroutine with code that dumps to the X16 emulator debug console: name of sub, stack pointer (for call depth!), emudbg cycle count. Save/restore all used registers!  Start of program must set cycle count to zero.