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In case of integer overflows what is the result of (unsigned int) * (int) ? unsigned or int?
I was auditing the following function, and suddenly I came out with that question. In the below function, it is vulnerable at line 17.
1. // Create a character...
Started by yinyueyouge on
, 12 posts
by 12 people.
Answer Snippets (Read the full thread at stackoverflow):
Return (NULL);
On int , unsigned int mixed operations, int is elevated to unsigned int....
In any case, i*w is guaranteed; 4096) 10.
Why not just declare i as unsigned int? Then the problem goes away.
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Suppose I have one long long int and want to take its bits and construct four unsigned short ints out of it.
Particular order doesn't matter much here.
I generally know that I need to shift bits and truncate to the size of unsigned short int. But I think...
Started by phjr on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
(unsigned short)((((unsigned long long int)value)>>(x))&(0xFFFF))
where....
Long long int long_long_int; unsigned short int short_ints[sizeof(long long int) / sizeof(short int.
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What requires the most CPU:
int foo = 3;
or typecasting it to an unsigned int?
unsigned int foo = 3;
Started by Midas on
, 10 posts
by 10 people.
Answer Snippets (Read the full thread at stackoverflow):
However assembly in MS VC 2005:
; 9 : int foo = 3; mov DWORD PTR _foo$[ebp], 3 ; 10 : unsigned int bar = 3 processors (although....
Here is the link about the fast types.
So there is no difference in speed.
Into unsigned int.
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The code is
return min + static_cast<int>(static_cast<double>(max - min + 1.0) * (number / (UINT_MAX + 1.0)));
number is a random number obtained by rand_s. min and max are ints and represent minimum and maximum values (inclusive).
If you ...
Started by phjr on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
You could do the arithmetic in an unsigned long long instead of a double, but only.
You should always do it by using high-order bits, as in
j = 1 + (int) (10.0 * (rand() / (RAND_MAX to double anyway.
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I have an application where part of the inner loop was basically:
double sum = 0; for (int i = 0; i != N; ++i, ++data, ++x) sum += *data * x;
If x is an unsigned int, then the code takes 3 times as long as with int!
This was part of a larger code-base...
Started by luispedro on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
int to doubles, but do not have a hardware conversion from unsigned to double, so the compiler software conversion from unsigned int to double may very well be suboptimal (it almost certainly [ebp-4] 0040E6E2 fstp qword ptr....
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Or to reformulate the question: is there a performance penalty in using unsigned values?
And in general: what is the most performant type (16bit signed?, 32bit signed? etc.) on the IPhone ARM processor?
Started by Ariel Malka on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
Consider this: You have a loop with an unsigned loop counter like this:
void function (unsigned int first, unsigned int last) { unsigned int i; for (i=first; i!=last; i++) { // do something here an 8-....
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Is there a method that converts string to unsigned int? _ultoa exists but couldn't find the vise verse version...
Answer Snippets (Read the full thread at stackoverflow):
#include <boost/lexical_cast.hpp> [...] unsigned int x = boost::lexical_cast<unsigned does under the covers):
#include <sstream> [...] std::stringstream s(strVal); unsigned int x; s >> x;
....
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#include <stdio.h>
int main() {
unsigned long long int num = 285212672; //FYI: fits in 29 bits
int normalInt = 5;
printf("My number is %d bytes wide and its value is %ul. A normal number is %d.\n", sizeof(num), num, normalInt);
return 0;
}
Output...
Started by superjoe30 on
, 13 posts
by 12 people.
Answer Snippets (Read the full thread at stackoverflow):
It's the %d => normal int which isn't working, which is to compile....
#include <stdio.h>
int main() {
unsigned long long int num and printing your unsigned long long int just fine.
Instead of 5 as it should.
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I am trying to convert a unsigned char* to int * on in Objective-C on the iPhone. Is there any API that can help with the conversion?
Here's my best attempt:
-(BOOL)MyFunc:Version:(int *)nVer { unsigned char * uszVerSize; //trying to assign string to ...
Started by KamalBhr on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Const char *asciiCString = [@"abc-zABC-Z" cString]; int.
Return [[NSNumber numberWithUnsignedChar:uszVerSize] intValue];
You a pointer to a char to a pointer to an int.
The chars to an int and return that.
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I got a problem with ip2long in PHP5. It appears, that in 32bit OS ip2long returns signed int, and in 64bit OS unsigned int is returned. My application is working on 10 servers, and some are 32bit and some are 64bit, so I need all them to work same way...
Started by Thinker on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Of ip2long into an unsigned int string by having sprintf interpret the value as unsigned with %u :
$ip_int; }
On a 64 bit system, printing this value ($ip_int) will display an 'unsigned' integer since with ip....
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