Use Convert.To after rounding in Pack() to avoid different behavior on ARM vs x86/x64 #1790
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## master #1790 +/- ##
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- Coverage 87.10% 87.03% -0.08%
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Files 936 936
Lines 47649 47631 -18
Branches 6015 6015
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- Hits 41506 41456 -50
- Misses 5150 5181 +31
- Partials 993 994 +1
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| @@ -523,7 +520,7 @@ private static string ToRgbaHex(string hex) | |||
| return hex + "FF"; | |||
| } | |||
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| if (hex.Length < 3 || hex.Length > 4) | |||
| if (hex.Length is < 3 or > 4) | |||
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At the expense of less readable code one can save a comparison here:
| if (hex.Length is < 3 or > 4) | |
| if ((uint)(hex.Length - 3) > (4 - 3)) |
BTW: is this method hot enough worth optimizing? One could save same allocations here.
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@gfoidl thanks for your feedback, but this is not a critical path. I rather keep this readable.
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Neat trick... Not hot. It's just used for parsing hex values which are generally defined outside loops.
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I wonder if we should replicate the behavior of the https://source.dot.net/#System.Private.CoreLib/Convert.cs,10cd63a0dc4a7c4c |
I dont know if its really worth for such niche pixel formats, like short2 and short4. |
| public readonly Vector4 ToVector4() => new Vector4(0, 0, 0, this.PackedValue / 255F); | ||
| public readonly Vector4 ToVector4() => new(0, 0, 0, this.PackedValue / 255F); |
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So type interference is something we prefer in the codebase?
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I like the shorter new(...) syntax very much. From your question im sensing you are not totally convinced?
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I don't have a strong preference, given up on code style battles long time ago 😄
Just want see us making a conscious decision on this, and have a preferred style established. @JimBobSquarePants your thoughts?
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I'm all in. I absolutely LOVE being able to declare on the left. 😍 Foo foo = new(bar); 😍
If we really want to spend time optimizing these methods, I'd rather explore how to SIMD them on x86. |
Prerequisites
Description
I noticed some pixelformat tests failing on ARM64. Namly short2, short4, normalizedbyte4 tests.
The reason for that is a cast from float to int in
Pack. on ARM this gets rounded to 0, if its negative, while on x86/x64 its not.For example:
Result on ARM64: 0
Result on x64: 4294967196 (uint.Max + f + 1)
To avoid the difference, i have added a
Convert.ToInt32after the rounding.The rest of the changes are some minor cleanup.