extract register input, output and operator from rtl right before peepholes

[Liu Haibin <liu dot haibin at gmail dot com>]

Hi,

I'd doing some coding right before peephole2 pass. I'd like to have a
function that takes rtl as input and returns the values of register
inputs, register output and operator. For example,

input:
(insn 496 34 29 1 (set (reg/f:SI 3 r3 [235])
        (plus:SI (reg/f:SI 3 r3 [235])
            (const_int 4 [0x4]))) 20 {addsi3} (insn_list:REG_DEP_ANTI 28 (nil))
    (nil))
returns:
inputs: r3, 4. ouput r3. operator: plus.

I know sched_analyze() in sched-deps.c builds the dependencies in
basic blocks and hope I can find some useful functions there. I
roughly went through the code and didn't really understand.

Because the rtl's are right before peephole2, they're much processed,
which makes things easier. I hope I can find some existing function to
use instead of using something like REGNO(XEXP(SET_SRC(PATTERN(x)),
0)). I believe sched-deps.c has something useful. Can someone help on
this?


Regards,
Haibin