Cheat Engine

Redouane · Posted: Tue Mar 17, 2015 8:57 am Post subject: Floor in FPU

Hello,I want to calculate the floor of the float value located at ST(0),I found this while searching:
frndint instruction
https://courses.engr.illinois.edu/ece390/archive/spr2002/books/labmanual/inst-ref-frndint.html
But I have no idea on how to edit the 'FPU control word'.
Thanks for any help.

vng21092 · Posted: Tue Mar 17, 2015 9:13 am Post subject:

hmm not sure why you would need to edit that but I just wanted to try it out here's how it turned out

Cool find, I have a thing for whole numbers Laughing

I don't think its something you can edit, its preset. Like if float is "x.5" it'll round up or round down, something like that.

Redouane · Posted: Tue Mar 17, 2015 10:58 am Post subject:

vng21092 · Posted: Tue Mar 17, 2015 11:06 am Post subject:

I'm guessing it just hops to the closest whole number. Judging from the other two values, we have -239.8 --> -240, and -270.6 --> -271. The link you posted says it rounds the number according to the current rounding mode. Here are two links that covers it slightly, hope it helps.

http://cs.fit.edu/~mmahoney/cse3101/float.html (All the way at the bottom "Rounding Control")

http://www.website.masmforum.com/tutorials/fptute/fpuchap1.htm (Near the middle "Control Word")

Redouane · Posted: Wed Mar 18, 2015 6:45 am Post subject:

justa_dude · Posted: Wed Mar 18, 2015 3:00 pm Post subject:

There's nothing preventing you from using a floor function in a loaded DLL (or loading a dll for the function you want). I don't know offhand how the native floor works, but I think that the msvcrt exports a floor function that takes a 4-byte float.

Zanzer · Posted: Wed Mar 18, 2015 7:00 pm Post subject:

This... should work. Smile