Documentation of the Speed and Size of (Almost) Every Axe Command

[ZippyDee]

But what causes it to not be usable at 15MHz?

[Munchor]

But what causes it to not be usable at 15MHz?

Its assembly code, somehow. Runer must have tried to optimize the code in a way that makes it impossible to 15MHz I guess.

[ZippyDee]

I know it's assembly. I understand that some optimization makes it impossible with 15MHz. But what's different at 15MHz than 6MHz?

[Freyaday]

The screen needs a delay of about 10microseconds between inputs, otherwise it shows garbage (not the band, sadly). @6MHz the processor is slow enough that this isn't a problem, but @ the higher speed it's faster than that.

[Deep Thought]

The screen needs a delay of about 10microseconds between inputs, otherwise it shows garbage (not the band, sadly). @6MHz the processor is slow enough that this isn't a problem, but @ the higher speed it's faster than that.

Yeah. Basically there is a delay included in the routine, and it's long enough in 6 MHz mode, but the 15 MHz processor goes through the delay too quickly.

[ZippyDee]

Is there no way to tell which mode it's in and only have it delay if it's at 16MHz?

[Runer112]

In the next version of Axe, Quigibo will releasing a fix that puts the calculator in 6MHz mode before running the DispGraph routine and then returns it to the CPU speed it was previously running at when it finishes.

[ZippyDee]

Awesome That sounds like it'll make it much easier.

[Runer112]

Updated for Axe 0.5.2. As usual, the updated file is attached to the first post. I'm also going to start a more detailed changelog, in case people are interested in knowing what exactly changed between versions of Axe. [NEW] denotes new Axe commands, [CHG] denotes changed Axe commands, and [FIX] denotes commands that haven't changed but have corrected information.

Changes:

• [FIX] Header size information
• [FIX] Added notes specifying that most 2-byte backwards loading commands are broken
• [CHG] Negative 8-bit constant equality checking (e.g. =⁻42) now works
• [NEW] Trivial comparisons ≥0, >65535, ≤65535, and <0
• [CHG] Constant unsigned comparisons (≥ > ≤ <) are smaller and faster  —  ~2 bytes smaller, ~8 cycles faster
• [CHG] >VAR and <EXPR optimized for size  —  1 byte smaller, 5 cycles slower
• [NEW] Optimizations for bitwise logic operations with constant operands
• [NEW] Optimized For() loops if the upper bound is a constant  —  1 byte smaller, 17 cycles faster
• [CHG] Nibble reading commands changed as a result of a bug fix and are now big-endian
• [NEW] Routine for preserving CPU speed and interrupt status before display commands
• [CHG] Adjusted all buffer display commands for the addition above
• [FIX] Speed estimates for commands that access the LCD
• [CHG] Full is smaller and faster  —  1 byte smaller, 3 cycles faster
• [CHG] All GetCalc() routines properly handle pointers to real and complex float variables
• [CHG] Archived variable locating routine optimized for size  —  5 bytes smaller
• [CHG] Pt-Mask() bug fix to work properly for aligned sprites

[DJ Omnimaga]

Nice, thanks for this

[Quigibo]

Just wanted to mention one other thing to add to the list; I turned the DispStrApp and TextStrApp inline routines into subroutines.

[Runer112]

Ah, so you have. I checked for that because I know I had suggested that change, but after a quick glance and not seeing any returns on the end I figured they hadn't changed. I didn't think to look for the conditional returns in the middle of the routines.

[Runer112]

Updated for Axe 0.5.3. As usual, the updated command information document is attached to the first post.


Changelog:
[NEW] denotes new Axe commands, [CHG] denotes changed Axe commands, and [FIX] denotes Axe commands that haven't changed but have corrected information. Red denotes a bug. Green denotes a change that I deem to be awesome.

• [CHG] All 2-byte big-endian loading and storing commands now work
• [FIX/0.5.2 CHG] Added trivial math operations +0, -0, *0, *1, *65535, /0, /1, //0, //1, ^1, ^65535        (If you're reading this Quigibo, did I miss any?)
• [FIX/0.5.2 CHG] Added notes specifying that //0 and ^65535 are mathematically incorrect
• [CHG] Any of the trivial math operations listed above that result in no compiled code cause a crash during compiling
• [NEW] Increment and decrement operators ++ and --
• [CHG] Nibble storing routine adjusted to access nibbles in big-endian format, like the nibble reading routines
• [FIX/0.5.2 CHG] The routines to draw strings in applications converted into subroutines
• [FIX] Adjusted the cycle estimates for p_NewLine, p_ClearScreen, and p_SaveToBuffer
• [CHG] Optimized p_FastCopy  —  1 byte smaller, 1548 cycles faster
• [CHG] Optimized p_DrawAndClr  —  2 bytes smaller, 1548 cycles faster
• [CHG] Optimized p_DispGS  —  ~5000 cycles faster
• [CHG] Speed-optimized p_Disp4Lvl and improved grayscale quality  —  3 bytes larger, ~7500 cycles faster
• [FIX] Adjusted the cycle estimate for p_DKeyExpr
• [FIX] Adjusted the cycle estimate for p_Div
• [FIX] Adjusted the cycle estimate and notes for p_SDiv
• [NEW] 8.8 fixed point reciprocal command ^-1  —  29 bytes, ~1349 cycles
• [CHG] Division and signed division have a bug that will cause them to always return 0 if the divisor is greater than 255
• [CHG] Speed-optimized p_Sqrt  —  15 bytes larger, ~5500 cycles faster
• [FIX] Added a note mentioning that p_FlipH can produce a garbage sprite

[Munchor]

Nice Runer112, cool you keep us updated

Also, is there a chance this can be released with Axe?

[Runer112]

If Quigibo wanted to release this with Axe, he'd either have to keep it up to date himself or give me new versions of Axe about a day in advance so I can update the file and give it back to him. Supposedly we're very close to Axe 1.0.0 though, for which he may or may not want a file like this being packaged into the sort of "final" version.