SquirrelJME/SquirrelJME

# 2015/07/15

***DISCLAIMER***: _These notes are from the defunct k8 project which_
_precedes SquirrelJME. The notes for SquirrelJME start on 2016/02/26!_
_The k8 project was effectively a Java SE 8 operating system and as such_
_all of the notes are in the context of that scope. That project is no_
_longer my goal as SquirrelJME is the spiritual successor to it._

## 10:34

I should be spitting out machine code very soon. My current only instruction
to be spit out is lwsync. Which current appears that it gets assembled as:
[FINEST] ASM: 0 0 0 0.

## 10:46

Some more fixing and lwsync is [FINEST] ASM: 0 4a c0 2. Although it should be
0: 7c 20 04 ac lwsync according to binutils.

## 10:52

The assembler wants to assemble AsmOp: (inst=SYNC addr=-1 len=4
args=[OPCD[[(0-6)]]:31, X_XO[[(21-10)]]:598, SYNC_L[[(9-2)]]:1,
SYNC_E[[(12-4)]]:0]). And 31 | (598 << 21) | (1 << 9) is
1254097439 or 0x4A C0 02 1F.

## 10:36

I desire `0b01111100 00100000 00000100 10101100` But I get instead `0b01001010
11000000 00000010 00011111` Which if you look at it appears rather swapped,
sort of.

## 11:08

Printing the fields gives me stuff such as 0b111110.

## 11:17

That is printing in the incorrect order. The printed field order is [FINEST]
0b011111 [FINEST] 0b01 [FINEST] 0b0000 [FINEST] 0b1001010110.

## 11:29

My reverse bit ordering gives me `0b-------- 11111000 01000000 00110000` which
is not correct.

## 12:00

Seems like one of my fields it not being printed.

## 12:10

Ok, now my instruction is:

    
    
    [FINEST] ASM: f8 40 03 52 0b11111000 01000000 00000011 01010010
                         need 0b01111100 00100000 00000100 10101100
    

## 12:19

Yipee! I believe I have it now!

    
    
    [FINEST] ASM: 7c 20 04 ac 0b01111100 00100000 00000100 10101100
                         need 0b01111100 00100000 00000100 10101100
                  7c 20 04 ac lwsync according to binutils.
    

So for PowerPC I needed to swap the instruction bits AND the field bits.
Normally big endian is on the byte level so it looks like: [8 9 10 11 12 13 14
15] [0 1 2 3 4 5 6 7], however PowerPC instructions are [15 14 13 12 11 10 9
8] [7 6 5 4 3 2 1 0].

## 15:58

Going to need to work on variable flowthrough (which gets what) and register
allocation.

## 18:14

One thing I can do though is that when it comes time to write a Java compiler
I can reuse the compiler system I am writing right now.

## 22:09

The SSA processing will be quite simple, it is just moving around of variables
and such to determine how good they are and such.