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Emulator Issues #13541

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Question about Paired Singles

Added by d01phin about 1 month ago. Updated about 1 month ago.

Status:
New
Priority:
Normal
Assignee:
-
% Done:

0%

Operating system:
N/A
Issue type:
Bug
Milestone:
Regression:
No
Relates to usability:
No
Relates to performance:
No
Easy:
No
Relates to maintainability:
No
Regression start:
Fixed in:

Description

Game Name?

Probably all GameCube games.
It's unknown that if the problem also apples to Wii games.

Game ID? (right click the game in the game list, Properties, Info tab)

Unrelated.

MD5 Hash? (right click the game in the game list, Properties, Verify tab, Verify Integrity button)

Unrelated.

What's the problem? Describe what went wrong.

I was trying to create a game mod by modifying game assemblies.

Everything goes well until I found that paired singles instructions produce unexpected results.
For example:
[code]; Before executing the instruction
; [r26] = 00 0c 00 0c ....
; qr4 = 0x00060006
; p0 = fff0000000000000 0000000000000000

psq_l p0, 2(r26), 1, qr4

; After executing the instruction:
; p0 = 0000000000000000 3ff0000000000000 // expected 4028000000000000 3ff0000000000000[/code]
This still happens even without breakpoints.

What steps will reproduce the problem?

Execute any [code]psq_l[/code] instructions.

Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.

Not sure, but I didn't find any change related to paired single from the source code on github after the installation.

Is the issue present in the latest stable version?

5.0-20213, which was the latest one when I installed it.

If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool https://forums.dolphin-emu.org/Thread-green-notice-development-thread-unofficial-dolphin-bisection-tool-for-finding-broken-builds and anyone who is building Dolphin on their own can use git bisect.)

See above.

If your issue is a graphical issue, please attach screenshots and record a three frame fifolog of the issue if possible. Screenshots showing what it is supposed to look like from either console or older builds of Dolphin will help too. For more information on how to use the fifoplayer, please check here: https://wiki.dolphin-emu.org/index.php?title=FifoPlayer

None.

What are your PC specifications? (CPU, GPU, Operating System, more)

It happens on all of my PC, so this should be unrelated.

Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)

None.

Actions #1

Updated by pokechu22 about 1 month ago

Is HID2[PSE] set to 1? If it's set to 0, then paired singles aren't enabled, and it's supposed to trigger the illegal instruction error handler, though it's possible that Dolphin doesn't do that.

Have you observed the the expected results on real hardware?

Actions #2

Updated by d01phin about 1 month ago

pokechu22 wrote in #note-1:

Is HID2[PSE] set to 1? If it's set to 0, then paired singles aren't enabled, and it's supposed to trigger the illegal instruction error handler, though it's possible that Dolphin doesn't do that.

Have you observed the the expected results on real hardware?

HID2 was 0xe0000000, which means PSE (bit2) is set.
Therefore I think paired singles are available.
I haven't tested it on real hardware yet, as the game mod is not completed.

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