We should have reaction emojis here instead of this stupid heart for everything. 
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We did.
Maybe some people got downvoted too often 
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What others exactly? This may have big impacts on an almost finished part of our code relying on dates (a major piece) depending.
Okay, seems there is evidence on this topics and Markusā (and othersā) observations.
I would like to see any statement by Xojo to this āExcel is working wrongā Momentā¦ or shall I better say Mars Orbiter Moment?
I am curious how other languages tackling this?
Has anybody tested Floor, Ceil & Round?
I know Min & Max have a similar problem with Int64 / UInt64 values because those functions only accept doubles.
integer div is also affected:
Dim d As Double = 3000000002.0
Dim n1 As Integer = d Mod 3
Dim n2 As Integer = d \ 3
Dim r1 As Integer = CType(d, Int64) Mod 3
Dim r2 As Integer = CType(d, Int64) \ 3
Break
In 64-bit app, those n1 and n2 will be wrong values.
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and as I love to look on the assembler for
Dim n1 As Integer = d Mod 3
I get this:
0x10012d466 <+150>: movb $0x1, %al
0x10012d468 <+152>: movq -0x60(%rbp), %rcx // load self
0x10012d46c <+156>: cvttsd2si -0xe0(%rcx), %edx // take double at address and convert to integer 32-bit!
0x10012d474 <+164>: movl %edx, -0x10(%rbp) // store it
0x10012d477 <+167>: testb $0x1, %al // always true!?
0x10012d479 <+169>: movl %edx, -0x64(%rbp) // store integer in temp variable
0x10012d47c <+172>: jne 0x10012d480 ; <+176>
0x10012d47e <+174>: jmp 0x10012d498 ; <+200>
0x10012d480 <+176>: movl $0x3, %eax // value 3
0x10012d485 <+181>: movl -0x64(%rbp), %ecx
0x10012d488 <+184>: movl %eax, -0x68(%rbp) // value 3 stored
0x10012d48b <+187>: movl %ecx, %eax
0x10012d48d <+189>: cltd // convert 32-bit EAX to 64-bit EDX:EAX!?
0x10012d48e <+190>: movl -0x68(%rbp), %esi // value 3 read
0x10012d491 <+193>: idivl %esi // divide by 3
0x10012d493 <+195>: movl %edx, -0xc(%rbp) // store mod result
0x10012d496 <+198>: jmp 0x10012d49b ; <+203>
0x10012d498 <+200>: movl %eax, -0xc(%rbp)
I added a few comments. And it looks like double conversion uses EDX as target instead of RDX for 64-bit. And later the 32-bit number is extended to 64-bit as division needs that as input.
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Yes. In writing my xDev article I needed to use both Mod and Integer division, and both have the problem.
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Maybe if people who have a few minutes could grab a function and test it, and post the code showing the problem?
The whole auto-type conversion/promotion for numbers should be rechecked. This part of the compiler is less safe than Fortran compilers I used more than 40 years ago. Puzzling.
Better documenting the rules of auto-type conversion/promotion could help (with examples : constants, functions, etc.). But fundamentally, the compiler should do a better job. CType is not the answer plus it is costly.
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I had to read up a bit on EDX and RDX.
I would have expected a conversion to Double to Integer to use Int64 or at least the system integer type.
Do I get this right that the integer conversion as seen on a 64bit system seems to be hardcoded to convert to Int32 (via EDX), and is not using the system integer type?
Or is that reading too much into it?
As far as I see, itās hard coded to use Int32 independent of CPU architecture.
I wonder how many times people have run into this and didnāt know it. I know Iāve had issues with things in the past that could have been affected by this sort of thing. I remember one particular project where I went through and manually setup a bunch of things to 64bit integers to try and work around a problem I thought was caused by integer overflow, but it may have been more than that. I also had some strange issues with an iOS project I built several years ago now I think, and Iām wondering if this issue wasnāt related to that as well. It used quite a bit of math to calculate speeds, distance, and time and it never seemed to work consistently. I eventually gave up on that project and havenāt revisitied iOS on Xojo since.
Xojo needs to fix this. I am not going to use a development environment that doesnāt handle basic match properly. This is not something I should need to deal with in a high level language.
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In feedback case 11536 got implemented by Paul. Great if he can do that and I hope they verified itās working better now.
@Paul_Lefebvre, did you also do change for \ operator?
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WOOHOO!
Took 10 years and Christianās detective work, but good news nonetheless!
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You have more cases to look into?
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Oh THIS one they fix, but comparisons suffering the same problem is vehemently not a bug? Come onā¦
#11935 and #2218. Both closed because Xojo doesnāt want to fix it.
I have a blog post about the issue, but Iām not going to link it due to forum rules.
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A small step for man, a giant leap for humanity. Letās see if they can take another step. 
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This is one of the MOST SERIOUS things that could ever happen, weāve had it before and moved on. Since then we have had this issue over 100ās of times and changed trough the use of the debugger to get the correct ifā¦ end if to happen. Itās a major waste of time, not knowing what to expect from the compiler while your brain says the value is for example:
// In a 32-bit app the following happens:
Var Value As UInt32 = 4294967295
If Value > 100 Then
// Won't Reach Here
End If
My brains where exploding almostā¦ We use Xojo always with sockets, binary streams etc. We have had these kind of min-blowing pain points alot. Never know what was the true problem. Moved onā¦ Now itās clearly showing what the actual problem is. Letās just fix this Xojoā¦ before this gets out of hand.
We have NEVER before used CType(ā¦) and donāt expect to have 100ās of lines of code (if not more) to be changed to add CType to itā¦ slowing things down and making things much more complex (and therefore more unclear).
I truely hope Xojo fixes this, even if it may break some projects. Donāt the right thing is MORE important than doing the WRONG thing and walking away from it.
Thanks to this amazing community we find such serious issues, so we should be able to expect a fix for these kind of time wasting bugsā¦
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Yes, the fix applies to both the Mod and Integer Division operators.
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