# 4.3 Basic block profilers  (Page 2/2)

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Let’s look at an illustration. Below is a short C program that performs a bubble sort of 10 integers:

``` int n[] = {23,12,43,2,98,78,2,51,77,8};main () {int i, j, ktemp; for (i=10; i>0; i--) { for (j=0; j<i; j++) { if (n[j]<n[j+1]) {ktemp = n[j+1], n[j+1]= n[j], n[j]= ktemp; }} }}```

tcov produces a basic block profile that contains execution counts for each source line, plus some summary statistics (not shown):

``` int n[] = {23,12,43,2,98,78,2,51,77,8};main () 1 ->{ int i, j, ktemp;10 ->for (i=10; i>0; i--) { 10, 55 ->for (j=0; j<i; j++) { 55 ->if (n[j]<n[j+1]) {23 ->ktemp = n[j+1], n[j+1]= n[j], n[j] = ktemp;} }} 1 ->}```

The numbers to the left tell you the number of times each block was entered. For instance, you can see that the routine was entered just once, and that the highest count occurs at the test `n[j]<n[j+1]` . tcov shows more than one count on a line in places where the compiler has created more than one block.

## Pixie

pixie is a little different from tcov . Rather than reporting the number of times each source line was executed, pixie reports the number of machine clock cycles devoted to executing each line. In theory, you could use this to calculate the amount of time spent per statement, although anomalies like cache misses are not represented.

pixie works by “pixifying” an executable file that has been compiled and linked in the normal way. Below we run pixie on foo to create a new executable called foo.pixie :

``` % cc foo.c -o foo % pixie foo% foo.pixie % prof -pixie foo```

Also created was a file named foo.Addrs , which contains addresses for the basic blocks within foo . When the new program, foo.pixie , is run, it creates a file called foo.Counts , containing execution counts for the basic blocks whose addresses are stored in foo.Addrs . pixie data accumulates from run to run. The statistics are retrieved using prof and a special –pixie flag.

pixie ’s default output comes in three sections and shows:

• Cycles per routine
• Procedure invocation counts
• Cycles per basic line

Below, we have listed the output of the third section for the bubble sort:

``` procedure (file) line bytes cycles % cum %main (foo.c) 7 44 605 12.11 12.11 _cleanup (flsbuf.c) 59 20 500 10.01 22.13fclose (flsbuf.c) 81 20 500 10.01 32.14 fclose (flsbuf.c) 94 20 500 10.01 42.15_cleanup (flsbuf.c) 54 20 500 10.01 52.16 fclose (flsbuf.c) 76 16 400 8.01 60.17main (foo.c) 10 24 298 5.97 66.14 main (foo.c) 8 36 207 4.14 70.28.... .. .. .. ... ...```

Here you can see three entries for the main routine from foo.c , plus a number of system library routines. The entries show the associated line number and the number of machine cycles dedicated to executing that line as the program ran. For instance, line 7 of foo.c took 605 cycles (12% of the runtime).

how can chip be made from sand
is this allso about nanoscale material
Almas
are nano particles real
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
no can't
Lohitha
where is the latest information on a no technology how can I find it
William
currently
William
where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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Rafiq
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Damian
How we are making nano material?
what is a peer
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What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
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Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
how did you get the value of 2000N.What calculations are needed to arrive at it
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