Consider this
bar = 1
foo = <1 or 2, depending on previous code>
if foo=1
while bar <= 5
[code].....
What I want to know is, is the compiler smart enough to optimize away the (apparently) repeated tests for "foo = 1" since foo is not modified in the body of the loop?If so, I might use the second construct since it is semantically equivalent (I think!), takes less code and reduces indentation levels.
I've read several articles and questions/answers that conclude the best practice is to let the JIT compiler do all the optimization for inline function calls. Makes sense. What about inline variable declarations? Does the compiler optimize these as well?
[Code]...
Of course I prefer the latter because it's easier to read and debug, but I can't afford the performance degradation if it exists. I have already identified this code as a bottleneck -- No need for retorts about premature optimization.
which compiler errors would be detected out by VB compiler?
I have searched out some compiler errors list for C#, for example, see the website at [URL]
MS provided us the information about C# compiler error. Does MS provide VB compiler errors information as well.VS
Imports System.CodeDom.Compiler
Public Class iCompiler
Public Shared Sub GenerateExecutable(ByVal Output As String, ByVal Source As String, ByVal Icon As String)[code].....
This error first appear to occur randomly. Steps to recreate:Open Visual Studio and load a solution (some files automatically opened) - this is when the problem occurs Close all open files Restart visual studio and load solution (no issues)Open Exactly the same files again, restart visual studio and load solution so files open automatically (problem occurs!)
However, when trying to narrow it down to a single file (that is automatically opened when the solution is loaded), I couldn't reproduce the problem. Now with all the files open again the problem doesn't occur!!! So it looks like it is fixed - though this happened before and eventually the issue came back.
I think it is to do with one of the user controls with DevExpress controls on it - when the error occurs, the designer displays the error. Though I can't reproduce it at the moment to confirm that.
If I look at the IL that is created in Linqpad for the two following code snippets, I wonder what happens here.
In c#
int i = 42;
results in the following IL code
IL_0000: ret
whereas in VB
Dim i As Integer = 42
it is
IL_0000: ldc.i4.s 2A
IL_0002: stloc.0
Apparently, the c# compiler understands the the value is never used and thus simply returns nothing. In VB.NET the actual code is translated.Is that due to differences in compiler optimization or is there anything else at work?
Update: Just to clarify this - I just enter this one line into LinqPad and look at the IL it creates (most definitely by running the respective compiler). There is no program.
I need to order lists of up to 100 addresses in optimized order. Is there a way to do this since getdirections is limited to 25? i don't se any way around this 25 limit. Is there one I'm missing?
No I'm trying to use MapPoint object model but it crashes as well with this many waypoints. Here is my example proof of concept code from Excel:
Sub OptimizeRoute()
Dim objApp As Object 'New MapPoint.Application
Dim objMap As Object 'MapPoint.Map
[Code]....
I had been working on a project that would generate a loan schedule.
But, It needs to factor in specified holidays and weekends.
Now, when running with a small 'term', it seems to work fine.[code]...
I need a list from OldGuids that are not in the NewGuids, so I used the Contains method, the problem is that it is already running more then half hour, is there a faster way? or how much longer would it take about? [code]
View 2 RepliesIs it possible to use a string as an array? I mean:' I have several arrays
Dim a10() As Integer = {530}
Dim a15() As Integer = {370, 231}
Dim a20() As Integer = {305, 176, 126}
'I declare a variable as a string and I assign the name of an array to it
Dim tablaalfa As String = "a10"
'I retrieve data from the array using the name of the variable instead:
lbl1.Text = tablaalfa(2)
I guess it doesn't work in this way?
vbc.exe has something called /optimize switch right. If I enable that what are the optimizations the compiler can do for me? The MSDN documentation just curtly says 'does various compiler optimizations'. Where can I find the complete quantified view of the different optimizations that actually goes into.Here is the thing I am pursuing this route. One of the code blocks in a module I am leading has a lot of delimited array manipulations. I believe this is going to be a heck costly in terms of string memory handling. I am looking to see if I can retire them by way of simple properties or methods so that the compiler can internally do something like our c++ inline functions making a best win-win offer in terms of both memory and processing time. I admit when the compiler translates them as inline function, the JITed code might be big in size right?
View 7 RepliesI basically want to remove the formula from the cells but want to retain the calculated values.
SO, I implemented it easily and it works great but REALLY SLOW. (About 2 mins for 1800 cells)
I have : Dim col As Excel.Range = getRange()For Each cell In col cell.Value = cell.Value Next
I tried to do this to the first cell and then autofill the rest, but that copied the value of 1st cell to the rest of the cells in column.
Want to dump a fetched table to a excel sheet. [code] I am new to data fetching and ADO.Net concepts and just got it working.But. This seems to be very inefficient and lame to me. So, can you help reducing the complexity and may be improve performance ? A totally different (Better) implementation is most welcome !
View 2 RepliesHow can I Optimize my own code written by VB.net? Is there any tools for it? Does Visual Studio have any one? What's your suggestion? I use VS2008 as my editor.
View 1 RepliesOften it is very usefull to save data as a class by serialize and compress it. From few experiments I have noticed that
Class A
Public name as string
Public List as new list(of string) <---- empty
End Class
Class B
Public name as string
Public List as list(of string) <----- not instantiated
End Class
If I serialize and compress the 2 classes the class B uses less spaces once serialized and compressed. This suggests me that if a class contains a list that is instantiated but empty it is better to set that to nothing and reset as new when it is decompressed and deserialized. Is there any dll that optimizes a class to be stored (serialized and compressed) and restore it when it is decompressed and deserialized?
Public Function CalCheckSum(ByVal ByteList As List(Of Byte)) As List(Of Byte)
Dim total As Integer = 0
For Each b As Byte In ByteList
[code]....
I fairly new to .Net. I did a small project a year or so ago but haven't coded in it since. I'm picking up maintenance of a project where items are selected from one listview and copied to another removing the selected item from the "parent". The current code is in two steps:1. Get the selected items removing from sender:
Public Function GetSelectedItems(Optional ByVal pRemoveFromList As Boolean = False) As ListView
Dim mList As New ListView
[code].....
When my form first loads, it runs at about 30k CPU, but after about 10 minutes of use, it goes up to (and stays at) about 70k CPU.
What ways can i optimize my code to allow the CPU usage to stay low, or how can i lower it during the running of the program.
My most concerned areas of the CPU are:
1. I have a web browser, and when a user types in a url and presses go or enter, the CPU jumps about 4k:
Private Sub Go_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Go.Click
WebBrowser1.Navigate(OldURL.Text)
[Code]....
The second worry is when i open other forms, it boosts the CPU up aswell. the only code for this is:
Form.Show()
I 'm currently developing program which I can check the lines of each textbox if it has same length. The code is working properly in few lines like 2000 lines, but when I try to load a textfile which has 50,000 lines, my program is not responding anymore it takes forever. [code]...
View 7 Repliesthis is in reference to my main post here update mdb with data from different tables in dataseti have two tables in a dataset called dsSource. dsSource.Tables(0) has the following columns: ,,,,,,,code,art,sizerng1,sizerng2,sizerng3,etc...... dsSource.Tables(1) has the following columns: ,,,,,,,code,art,size1,size2,size3,etc...... the conditions here are: 1) to look for "1" in columns sizerng1, sizerng2, etc. of dsSource.Tables(0) 2) match code and art on both tables finally if both conditions are valid then the size values in columns size1, size2, etc. will be assigned to columns in sizerng1, sizerng2, etc. my main concern here is i have to loop through all rows in both tables which takes a long time, so is there a better way to do this than the code i have below?.
'***put the sizes from weights to traps file
row1 = 0
For Each dr As DataRow In dsSource.Tables(0).Rows
[code].....
I have this seperate class to fill a treeview from my database.There are over 33000 records and when this class runs, it takes almost 1 minute to finish.When i run this query from the server it takes for 5 seconds to retrieve all items.Is there a way to optimize this class?
Option Explicit On
Option Strict On
Imports System.Windows.Forms
[code]....
Code:
Tables:
- Company
- Department
- Employee
- CertificationA
- CertificationB
I am trying to return a recordset that gives some summary information about each company. The fields in my returned recordset should look like the following.
Company.Name, NumberOfDepartments, NumberOfEmployees, NumberOfCertificationA, NumberOfCertificationACompleted, NumberOfCertificationB, NumberOfCertificationBCompleted
There are actually about 10 different Certification tables but, with Certification A and B you should get the hang of it. When an employee starts a certifaction, a record is added to the that certification table.Below is a query I wrote that works (gets me the data I need), but I am unsure if it is the most efficient way. There will be quite a lot of data so performance is an issue.
Code:
Dim sqlNumberOfDepartments As String
sqlNumberOfDepartments = _
"(SELECT COUNT(*) " & _
"FROM DEPARTMENT " & _
[code].....
I'm working on building an HTTPHandler that will serve up plain text for use with jQuery Autocomplete. I have it working now except for when I insert the first bit of text it does not take me to the right portion of the alphabet.[code]...
My question is, how would I implement this concept into my HTTPHandler without doing a fresh SQLQuery on every character change? IE: I do the SQL Query on the QueryString("ID"), and then on every subsequent load of the same ID, we just filter down the "Part".[url]...
My LINQ query contains the following Group By statement:
Group p By Key = New With { _
.Latitude = p.Address.GeoLocations.FirstOrDefault(Function(g) New String() {"ADDRESS", "POINT"}.Contains(g.Granularity)).Latitude, _
.Longitude = p.Address.GeoLocations.FirstOrDefault(Function(g) New String() {"ADDRESS", "POINT"}.Contains(g.Granularity)).Longitude}
The query works, but here is the SQL that the clause above produces
SELECT [t6].[Latitude]
FROM (
SELECT TOP (1) [t5].[Latitude]
[Code]....
but this produced an error: "A group by expression can only contain non-constant scalars that are comparable by the server."
1) is vb6 is interpreter based languge or compiler based or both interpreter and compiler based language?
2) is VB.Net interpreter based languge or compiler based or both interpreter and compiler based language?
3) if any of above mentioned is both interpreter and compiler based so tell me please when it compiles and when it interprets?
how to create my own programming language,I can create a compiler for a language like vb.net itself. Essentially, the user inputs code, they get a .exe. By NO MEANS do I want to write my own language, as it seems other compiler related questions on here have asked. I also do not want to use the vb.net compiler itself, nor do I wish to duplicate the IDE.
The exact purpose of what I wish to do is rather hard to explain, but all I need is a nudge in the right direction for writing a compiler (from scratch if possible) which can simply take input and create a .exe. I have opened .exe files as plain text before (my own programs) to see if I could derive some meaning from what I assumed would be human readable text, yet I was obviously sorely disappointed to see the random ascii, though it is understandable why this is all I found.
I know that a .exe file is simply lines of code, being parsed by the computer it is on, but my question here really boils down to this: What code makes up a .exe? How could I go about making one in a plain text editor if I wanted to? (No, I do not want to do that, but if I understand the process my goals will be much easier to achieve.) What makes an executable file an executable file? Where does the logic of the code fit in?
This is intended to be a programming question as opposed to a computer question, which is why I did not post it on SuperUser. I know plenty of information about the System.IO namespace, so I know how to create a file and write to it, I simply do not know what exactly I would be placing inside this file to get it to work as an executable file.
I am underway to develop a VB.Net compiler using visual studio 2005, but so far I am not aware on how to go about, regarding to what are the key requirements or skills required for developing a compiler.
View 3 RepliesHow can i make my own compiler ?
View 5 RepliesI have a program using vs 2008 (as 3.5) and code in vb. The site has been running nicely for 3 years, but suddenly the error message has come: BC 30451 Name 'class 2' is not defined. Call Class2.open_connection(cn, Session("datapath")) But in my local computer and in the site server the particular line mentions class1 only and not class 2!
View 5 RepliesI am running visual studio 2008 with SP1 installed. I have a solution which has 7 projects. One of the vb files (which has some 15000 lines) is freezing the visual studio and when i close the studio it shows the visual basic compilation error. I have tested the solution in other workstations and it is running fine. I tried repairing visual studio and i tried reparing 3.5 sp1.
View 1 Replies