Loop index int i was being compared against GetControllerCount() which
returned a size_t. This was the only place GetControllerCount() was
called from so the change of return type doesn't disturb anything else.
Changing the loop index to size_t wouldn't work as well since it's
passed into GetController(), which takes an int and is called from many
places, so it would need a cast anyway on an already busy line.
...and let's optimize a divisor of 2 ever so slightly for good measure.
I wouldn't have bothered, but most GameCube games seem to hit this on
launch.
- Division by 2
Before:
41 BE 02 00 00 00 mov r14d,2
41 8B C2 mov eax,r10d
45 85 F6 test r14d,r14d
74 0D je overflow
3D 00 00 00 80 cmp eax,80000000h
75 0E jne normal_path
41 83 FE FF cmp r14d,0FFFFFFFFh
75 08 jne normal_path
overflow:
C1 F8 1F sar eax,1Fh
44 8B F0 mov r14d,eax
EB 07 jmp done
normal_path:
99 cdq
41 F7 FE idiv eax,r14d
44 8B F0 mov r14d,eax
done:
After:
45 8B F2 mov r14d,r10d
41 C1 EE 1F shr r14d,1Fh
45 03 F2 add r14d,r10d
41 D1 FE sar r14d,1
Add a function to calculate the magic constants required to optimize
signed 32-bit division.
Since this optimization is not exclusive to any particular architecture,
JitCommon seemed like a good place to put this.
Zero divided by any number is still zero. For whatever reason, this case
shows up frequently too.
Before:
B8 00 00 00 00 mov eax,0
85 F6 test esi,esi
74 0C je overflow
3D 00 00 00 80 cmp eax,80000000h
75 0C jne normal_path
83 FE FF cmp esi,0FFFFFFFFh
75 07 jne normal_path
overflow:
C1 F8 1F sar eax,1Fh
8B F8 mov edi,eax
EB 05 jmp done
normal_path:
99 cdq
F7 FE idiv eax,esi
8B F8 mov edi,eax
done:
After:
Nothing!
When the dividend is known at compile time, we can eliminate some of the
branching and precompute the result for the overflow case.
Before:
B8 54 D3 E6 02 mov eax,2E6D354h
85 FF test edi,edi
74 0C je overflow
3D 00 00 00 80 cmp eax,80000000h
75 0C jne normal_path
83 FF FF cmp edi,0FFFFFFFFh
75 07 jne normal_path
overflow:
C1 F8 1F sar eax,1Fh
8B F8 mov edi,eax
EB 05 jmp done
normal_path:
99 cdq
F7 FF idiv eax,edi
8B F8 mov edi,eax
done:
After:
85 FF test edi,edi
75 04 jne normal_path
33 FF xor edi,edi
EB 0A jmp done
normal_path:
B8 54 D3 E6 02 mov eax,2E6D354h
99 cdq
F7 FF idiv eax,edi
8B F8 mov edi,eax
done:
Fairly common with constant dividend of zero. Non-zero values occur
frequently in Ocarina of Time Master Quest.
Whether the custom RTC setting is enabled shouldn't in itself
affect determinism (as long as the actual RTC value is properly
synced). Alters the logic added in 4b2906c.
I'm not entirely certain that this is correct, but the current
code doesn't really make sense to me... If we need to force the
RTC bias to 0 when custom RTC is enabled, why don't we need to
do it when custom RTC is disabled? The code for getting the
host system's current time doesn't contain any special handling
for the guest's RTC bias as far as I can tell.
The loop in WIARVZFileReader::Chunk::Read could terminate
prematurely if the size argument was smaller than the size
of an exception list which had only been partially loaded.
BPMEM_TEV_COLOR_ENV + 6 (0xC6) was missing due to a typo. BPMEM_BP_MASK (0xFE) does not lend itself well to documentation with the current FIFO analyzer implementation (since it requires remembering the values in BP memory) but still shouldn't be treated as unknown. BPMEM_TX_SETMODE0_4 and BPMEM_TX_SETMODE1_4 (0xA4-0xAB) were missing entirely.
Additional changes:
- For TevStageCombiner's ColorCombiner and AlphaCombiner, op/comparison and scale/compare_mode have been split as there are different meanings and enums if bias is set to compare. (Shift has also been renamed to scale)
- In TexMode0, min_filter has been split into min_mip and min_filter.
- In TexImage1, image_type is now cache_manually_managed.
- The unused bit in GenMode is now exposed.
- LPSize's lineaspect is now named adjust_for_aspect_ratio.
Additionally, VCacheEnhance has been added to UVAT_group1. According to YAGCD, this field is always 1.
TVtxDesc also now has separate low and high fields whose hex values correspond with the proper registers, instead of having one 33-bit value. This change was made in a way that should be backwards-compatible.
We want to save the currently selected platform tab,
but doing so immediately after switching tabs leads to
unnecessarily much file I/O (on the main thread, no less).
This change makes us defer the saving until later.
Dentomologist