(34S) Integration (using the double-exponential method)

[Paul Dale]

(03-25-2017 11:52 PM)emece67 Wrote:  It does the very same thing, in this respect, that the built in integrator: corrupt all the stack.

The built in integrator doesn't corrupt the stack. It leaves the integral in X, the error estimate in Y and the original limits of integration in Z & T and also preserves the original X value in L. Refer to the 34C manual page 211. I'm don't remember what it does to A, B, C & D with stack size 8 -- XROM switches to four level stack mode on entry so they won't be directly altered, although the fills before calling user code might.

Quote:I do not want to use xIN/xOUT because it forces DBLON mode and because I'm not sure if XEQUSR/POPUSR can be used inside xIN/xOUT.

xIN/xOUT cannot nest so they cannot be used in integrate because the user's program might use a function that uses xIN/xOUT.

Quote:In any case, I'm still trying to fix this (looking into ->ABCD->).

[->]A..D and A..D[->] stash these four registers away in temporary volatile memory. They provided a way to gain some extra working registers before we had locals. It must be assumed that the temporary registers are lost when XEQUSR is called.


- Pauli