473,406 Members | 2,549 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,406 software developers and data experts.

register variables

hi , can someone tell that why cant a variable declared with acess specifier as register globally.
Aug 24 '07 #1
2 1271
Meetee
931 Expert Mod 512MB
hi , can someone tell that why cant a variable declared with acess specifier as register globally.
Hi,

I have not understood your question completely because of lack of details but if you want to declare variable that stores in register then use this register keyword:

register int i;

Regards
Aug 24 '07 #2
gsi
51
Hi,
Declaring a register variable globally is not legal c. It is going to consume one register throughout your program, Hence they are allowed only for local variables, so that the register can be freed on the scope exit. Register storage class specifier for local variables itself is not guaranteed to be honoured by the compiler.

GNU c allows that as an extension , but u have to explicitly specify what register to use, and the register name is cpu dependent.

Thanks,
gsi.
Aug 24 '07 #3

Sign in to post your reply or Sign up for a free account.

Similar topics

3
by: Alex | last post by:
I apoligise in advance if this is an os or platform based question, I don't know. I was wondering how register integers (and other types of register variables) are managed by c++. For example,...
10
by: ajay | last post by:
some say floats can't be stored in register. size of int and float are same ( on some machine am i Wrong?) so if int can be delcared as register than why not float(where in and float are of same...
14
by: aruna | last post by:
What is the disadvantage of using register storage class specifier?
16
by: alakesh.haloi | last post by:
Hi All Is there a limit on the number of register variables that can be declared and initialized in a C program on a particular hardware platform? If you define more number of register variables...
16
by: junky_fellow | last post by:
what is the purpose of declaring a register variable ? why can't we find the address of register variable ?
7
by: int main(void) | last post by:
Hi all, I know that register variables work fine at block scope. I tried putting a register variable in file scope, like this, #include <stdio.h> register int a = 2; int main(void) {...
33
by: Snis Pilbor | last post by:
With the "as if" rule in play, doesn't that effectively render the "register" keyword completely useless? Example: I make a silly compiler which creates code that goes out of its way to take a...
28
by: sowmiyakc18 | last post by:
Please clear my doubt. When do we declare a variable to be a register variable? What is its significance? What are the conditions to be adhered to when register variables are passed between...
26
by: Vashna | last post by:
Hi Group, I have a doubt about register variables. I know that if we have a variable used very frequently in a function, then provided we never apply the & function to it, we can define it as...
7
by: RANNA | last post by:
Say the CPU has only AL, BL, CL, DL or eight 8 bit registers, and if want to declare 10 register variables in my code, is it possible to do it?
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
by: Hystou | last post by:
There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
0
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However,...
0
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
0
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.