The dolphin-redirect.php script seems to have been present since 2012
at least, but we accidentally stopped using it when the "open wiki"
feature was reimplemented in DolphinQt2 in 2016.
<@delroth> dolphin-redirect.php is slightly smarter and tries to find gameid aliases for e.g. same region
<@delroth> uh, I mean different region
PR 9262 added a bunch of Jit64 optimizations, some of
which were already in JitArm64 and some which weren't.
This change ports the latter ones to JitArm64.
OR allows for a more compact representation for constants that can be
represented by a signed 8-bit integer, while MOV does not. By letting
MOV handle the larger constants we can occasionally save a byte.
Before:
45 8B F5 mov r14d,r13d
41 81 CE 00 80 01 00 or r14d,18000h
After:
41 BE 00 80 01 00 mov r14d,18000h
45 0B F5 or r14d,r13d
Bitwise or with zero is just a fancy MOV, really.
- Example 1
Before:
41 BA 00 00 00 00 mov r10d,0
45 0B D1 or r10d,r9d
After:
45 8B D1 mov r10d,r9d
- Example 2
Before:
41 83 CA 00 or r10d,0
After:
Nothing!
AND allows for a more compact representation for constants that can be
represented by a signed 8-bit integer, while MOV does not. By letting
MOV handle the larger constants we can occasionally save a byte.
Before:
41 8B FE mov edi,r14d
81 E7 FF FE FF FF and edi,0FFFFFEFFh
After:
BF FF FE FF FF mov edi,0FFFFFEFFh
41 23 FE and edi,r14d
XOR allows for a more compact representation for constants that can be
represented by a signed 8-bit integer, while MOV does not. By letting
MOV handle the larger constants we can occasionally save a byte.
Before:
44 89 F7 mov edi,r14d
81 F7 A0 52 57 01 xor edi,15752A0h
After:
BF A0 52 57 01 mov edi,15752A0h
41 33 FE xor edi,r14d
In the case of eqvx, the final complement can always be baked directly
into the immediate value.
Before:
45 8B EF mov r13d,r15d
41 F7 D5 not r13d
41 83 F5 04 xor r13d,4
After:
45 8B EF mov r13d,r15d
41 83 F5 FB xor r13d,0FFFFFFFBh
PowerPC instructions andcx and orcx complement the value of register b
before performing their respective bitwise operation. If this register
happens to contain a known value, we can precompute the complement,
allowing us to generate simpler code.
- andcx
Before:
BF 00 01 00 00 mov edi,100h
F7 D7 not edi
41 23 FE and edi,r14d
After:
41 8B FE mov edi,r14d
81 E7 FF FE FF FF and edi,0FFFFFEFFh
- orc
Before:
41 BE 04 00 00 00 mov r14d,4
41 F7 D6 not r14d
45 0B F5 or r14d,r13d
After:
45 8B F5 mov r14d,r13d
41 83 CE FB or r14d,0FFFFFFFBh
