Some of the code used when the carry flag is known to be a
constant value is really not much better than just setting
the carry flag and then using the normal code, and with how
rarely this code runs, it isn't well tested either.
Might as well get rid of some of this code and simplify things.
These optimizations were already present, but only when d == a. They
also make sense when this condition does not hold.
- imm == 0
Before:
41 BB 00 00 00 00 mov r11d,0
45 2B DF sub r11d,r15d
After:
45 8B DF mov r11d,r15d
41 F7 DB neg r11d
- imm == -1
Before:
41 BD FF FF FF FF mov r13d,0FFFFFFFFh
44 2B EE sub r13d,esi
0F 93 45 68 setae byte ptr [rbp+68h]
After:
44 8B EE mov r13d,esi
41 F7 D5 not r13d
C6 45 68 01 mov byte ptr [rbp+68h],1
Without this, the code added in ac28b89 misbehaves and considers
AArch64 netplay clients to not have hardware FMA support, telling
all clients to disable FMA support, which causes a desync between
x64 and AArch64 due to JitArm64 not being able to disable FMA support.
Fixes a regression from 5.0-12066, where setting the GFXBackend variable
to one other than the current global backend would crash Dolphin upon
launching the game.
fcmpX only updates the FPCC bits, not the C bit.
This was already correctly implemented in the interpreter.
Not known to affect any games, but affects a hardware test.