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Line 2,093: Line 2,093:
  ori a,a, 0xXXXX
  ori a,a, 0xXXXX
  lvx d,a, 0x0
  lvx d,a, 0x0
Accurate add/sub is really over-complicated, I think is possible to shrink it to prevents slow downs and cache resets when overused. For example instead of creating "constants", we can really use constants from unused memory. On every single accurate add/sub emulator run this code:
0x18726C    li        r9, -1                # --- start of "constants" creation ---
0x187270    clrlwi    r9, r9, 1            # r9 = 0x7FFFFFFF
0x187274    stw      r9, 0x20(r31)
0x187278    li        r9, 0xFF
0x18727C    stw      r9, 0x24(r31)
0x187280    li        r9, 31
0x187284    stw      r9, 0x28(r31)
0x187288    li        r9, 23
0x18728C    stw      r9, 0x2C(r31)
0x187290    li        r9, 0x20 # ' '
0x187294    lvxl      v16, r9, r31          # Load from 0x20(r31)
0x187294                                    # [0x7FFFFFFF, 255, 31, 23]
0x187298    li        r9, 0x97
0x18729C    stw      r9, 0x20(r31)
0x1872A0    clrlslwi  r9, r9, 31,23        # 4B800000 ?
0x1872A4    stw      r9, 0x24(r31)
0x1872A8    li        r9, 25
0x1872AC    stw      r9, 0x28(r31)
0x1872B0    li        r9, -1
0x1872B4    clrrwi    r9, r9, 8            # r9 = 0xFFFFFF00
0x1872B8    stw      r9, 0x2C(r31)
0x1872BC    li        r9, 0x20 # ' '
0x1872C0    lvxl      v15, r9, r31          # Load from 0x20(r31)
0x1872C0                                    # [0x97, 0x4B800000, 25, 0xFFFFFF00]
0x1872C0                                    # End of "constants" creation.
All that to load vector v15 with [0x97, 0x4B800000, 25, 0xFFFFFF00], and v16 with [0x7FFFFFFF, 255, 31, 23]. This is really painful when you need to do that on every accurate add/sub, 22 opcodes, even more cycles. But what if we patch emulator to have those values for example at 0x7000 - 0x701F offset? Then loading constants will be:
0x18726C    li        r9, 0x7000
0x187270    lvxl      v16, r9, r0
0x187274    addi      r9, r9, 0x10
0x187278    lvxl      v16, r9, r0
From 22 opcodes we end up with 4. 18 opcodes less on every accurate add/sub. Additionally we can skip preserving/restoring of LR, CTR, and maybe XER. That give another saving of 12 opcodes. Additional 2 opcodes could be saved by not using r6 as temp for save/restore values. We can reuse r9 instead, so there is no need to preserve/restore old r6. All that shrink add/sub from 216 opcodes to 184. For FPU add/sub even more could be done, but for VU/COP2 its most likely only possible optimisation. Still worth it, should bring noticeable difference in framerate on intensive games that need it.


== Ugly fix for HDD whitelisted games loaded through Cobra ==
== Ugly fix for HDD whitelisted games loaded through Cobra ==
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