For the non-packed variant of this instruction, a MOVSD instruction was
generated to copy only the lower 64 bits of XMM1 to the destination
register. This was done in order to keep the destination register's
upper half intact.
However, when register c and the destination register are the same,
there is no need for this copy. Because the registers match and due to
the way the mask is generated, BLENDVPD will end up taking the upper
half from the destination register, as intended.
Additionally, the MOVAPS to copy Rc into XMM1 can also be skipped.
Before:
66 0F 57 C0 xorpd xmm0,xmm0
F2 41 0F C2 C6 06 cmpnlesd xmm0,xmm14
41 0F 28 CE movaps xmm1,xmm14
66 41 0F 38 15 CA blendvpd xmm1,xmm10,xmm0
F2 44 0F 10 F1 movsd xmm14,xmm1
After:
66 0F 57 C0 xorpd xmm0,xmm0
F2 41 0F C2 C6 06 cmpnlesd xmm0,xmm14
66 45 0F 38 15 F2 blendvpd xmm14,xmm10,xmm0
For the non-packed variant of this instruction, a MOVSD instruction was
generated to copy only the lower 64 bits of XMM1 to the destination
register. This was done in order to keep the destination register's
upper half intact.
However, when register c and the destination register are the same,
there is no need for this copy. Because the registers match and due to
the way the mask is generated, VBLENDVPD will end up taking the upper
half from the destination register, as intended.
Before:
66 0F 57 C0 xorpd xmm0,xmm0
F2 41 0F C2 C6 06 cmpnlesd xmm0,xmm14
C4 C3 09 4B CA 00 vblendvpd xmm1,xmm14,xmm10,xmm0
F2 44 0F 10 F1 movsd xmm14,xmm1
After:
66 0F 57 C0 xorpd xmm0,xmm0
F2 41 0F C2 C6 06 cmpnlesd xmm0,xmm14
C4 43 09 4B F2 00 vblendvpd xmm14,xmm14,xmm10,xmm0
Any call to Config::SetCurrent will cause the relevant setting
to show up as overridden in the Android GUI, which can be confusing,
so let's not do it when the new value is the same as the original.
SYSCONF very much is saveable. Whether it's in IsSettingSaveable
or not hasn't mattered until now since the SYSCONF settings use
separate config loader code that doesn't check IsSettingSaveable,
but the next commit will require SYSCONF to be marked as saveable.
Fixes https://bugs.dolphin-emu.org/issues/12245.
I considered making a change to DolphinQt instead of
the core, but then additional effort would've been
required to add the same fix to the Android GUI once
we start using the new config system there.
In particular, I wanted to do change this in
AudioInterface::Init so that dumped GC audio doesn't need
to have a file split (changing from 32000 Hz to 32029 Hz)
when the emulated software initializes the AI registers.
I've also made the same change to DI's DTK code.
