Print Page - Loading into floats?

Title: Loading into floats?
Post by: Mathew_Wi on July 28, 2010, 01:58:38 AM

Hi, I'm trying to load the value from r12 into f12.

Doesn't seem to work.

r12 : C6FA0000
f12 : 60000000

lfs f12,0(r12)

Am I doing something wrong?

Title: Re: Loading into floats?
Post by: dcx2 on July 28, 2010, 02:45:39 AM

Yeah. Floats are loaded and stored from memory, not other registers.

0(r12) means load the value that r12 is pointing at.

Title: Re: Loading into floats?
Post by: matt123337 on July 28, 2010, 04:49:37 PM

Quote from: Mathew_Wi on July 28, 2010, 01:58:38 AM
Hi, I'm trying to load the value from r12 into f12.

Doesn't seem to work.

r12 : C6FA0000
f12 : 60000000

lfs f12,0(r12)

Am I doing something wrong?

find some empty place in memory. I'n my example i'll use 0x8000098

Code Select


lis r9, 0x8000 # base address
lis r12, 0xC6FA # value u want to load into float register
stw r12, 0x98(r9) # stores value into memory at 0x8000098
lfs f12, 0x98(r9) # reads value from 0x8000098 into f12

Title: Re: Loading into floats?
Post by: dcx2 on July 28, 2010, 04:59:27 PM

That makes me nervous...r9 needs to be safe, and I'm not sure that 0x80000098 is free.

I believe ZiT used a "negative stack frame" for loading floats in an SMG2 code.

lis r12, 0xC6FA
stw r12,-4(r1)
lfs f12,-4(r1)

Title: Re: Loading into floats?
Post by: matt123337 on July 28, 2010, 05:26:28 PM

it is safe, he's hacking Legend of Zelda: Ocarina of Time. I just check :p

WiiRd forum

Wii & Gamecube Hacking => Wii Game hacking help => Topic started by: Mathew_Wi on July 28, 2010, 01:58:38 AM