3 ms·
Technically it has to point to _a_ valid frame, but it doesn’t have to be the active function’s frame. So it’s safe to omit setting up a normal call frame, you
by stephencanon 4y ago
Technically it has to point to _a_ valid frame, but it doesn’t have to be the active function’s frame. So it’s safe to omit setting up a normal call frame, you just aren’t supposed to use it as a GPR.
- stephencanon 4y agoI.e. don’t do what a former coworker did (on x86) and use both the stack pointer and frame pointer registers as index registers for your FFT implementation.
- saagarjha 4y agolmao
- stephencanon 4y agoWhen you only have a few GPR names, this sort of thing starts to look tempting. IIRC it was about a 10% perf win, but we didn’t ship it. (We did ship one that used the frame pointer as an index, though.)