/prog/ - CFLAGS Just kicked In

Name: Anonymous 2010-07-09 3:20

Show me your CFLAGS.
This is mine:
-march=native -O1 -ffast-math -funroll-loops -fpeel-loops -funswitch-loops -fpredictive-commoning -finline-functions -findirect-inlining -foptimize-sibling-calls -fmove-loop-invariants -s -Wall

Name: Anonymous 2010-07-09 3:34

VROOM VROOM

Name: Anonymous 2010-07-09 3:39

-funroll-loops -funswitch-loops
I only use funny compiler switches

Name: HASKAL MEME FAN 2010-07-09 3:52

-fvia-C -dynamic -threaded -O2 -fexcess-precision -fliberate-case -funbox-strict-fields -funfolding-creation-threshold=666

SORRY I CAN'T HEAR YOU GUYS OVER THE SOUND OF MY JET ENGINE

Name: Anonymous 2010-07-09 4:15

what are cflags? how do i check them on ububtu (karmic)?

Name: Anonymous 2010-07-09 5:46

-I $(UBOOT)/include -D__KERNEL__ -fno-builtin -D__FLASHED__ -I . -I $(ROOT)/include -I $(CDIR) -D__ARM__ -mcpu=arm920t -mlong-calls -std=gnu99 -Os -D__arm__ $(CFLAGS) -include $(ROOT)/config.h

Name: Anonymous 2010-07-09 7:59

-fOMG-OPTIMIZED

VROOM VROOM!!!

Name: Anonymous 2010-07-09 9:44

Minor observations:
O1 is fastest in most programs on newer GCCs. If the code uses alot of indirection/branching/trickery O2/O3 can help it but the speed increase is neglicible(+15%/-20%) and it takes much longer to compile.
fast-math gains ~10% speed
-funroll-loops -fpeel-loops -funswitch-loops
add 5-10%, 10% more if the code is unoptimized/naive loops
-mfpmath=sse should be used IMHO with all numerical codes.GCC has some great SSE transforms which can add 70%-100% speed.
However there is code more optimized for x87 floating point and it is faster than using SSE(SSE has huge latency).

Name: Anonymous 2010-07-09 12:06

-Os

Name: Anonymous 2010-07-09 14:23

how do i check these CFLAGS things on xp service pack 2?

Name: FrozenVoid 2010-07-09 14:46

>>10 you add them yourself usually, like "gcc -funtroll-loops" or (in batch file the %1 is a somesource.c file):
@..\gcc -Wall -s -pipe -O -mfpmath=sse -march=native -mrecip -ffast-math -fstrict-overflow -funroll-loops -fpeel-loops -funswitch-loops -fprefetch-loop-arrays -fpredictive-commoning -findirect-inlining -finline-functions -foptimize-sibling-calls -feliminate-unused-debug-types -fno-exceptions -fno-unwind-tables -ffunction-sections -fbranch-target-load-optimize2 -fdelete-null-pointer-checks -fno-stack-protector -fno-defer-pop -fno-branch-count-reg -fcrossjumping %1

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Name: Anonymous 2010-07-09 14:51

SPEED = -02 -ffast-math -fno-rtti -fno-exceptions



WARNINGS = \

        -Wall -Wextra -Wstrict-aliasing \

        -Wno-unused-parameter \          

        -Wcast-qual -Wcast-align -Wwrite-strings \

        -fno-common \                             

        -Wformat=2 -Wfloat-equal \                

        -Wno-deprecated-declarations \            

        -Werror



CFLAGS := $(FLAGS) $(CFLAGS) $(WARNINGS) $(SPEED)

-Wall -Wextra -Werror: NO EXCEPTIONS

Name: Anonymous 2010-07-09 14:52

-Wall -Wextra -Werror -pedantic -O2

I'm a casual programmer.

Name: Anonymous 2010-07-09 14:55

I normaly dont specify any flags at all.

Name: Anonymous 2010-07-09 14:58

>>13
I approve of this use of pedantry.

Name: Anonymous 2010-07-09 15:14

I usually just use -Wall -Wextra -Werror -pedantic. All of this zoomj-fast Gentooing is just trying to get the compiler to correct for the fact that you suck at C anyway.

Name: FrozenVoid 2010-07-09 15:21

>>16
Try for a change to time(either a RDTSC or clock() will do) your "Wall" vs switches in >>11

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Name: Anonymous 2010-07-09 15:27

>>17
What the fuck did you just say, and does it matter? These kids program in Haskell, it's not like they really care about speed

Name: FrozenVoid 2010-07-09 15:36

>>18 RDTSC ->Performance measurements for loops/functions
A program compiled with GCC optimizations like in >>11 can be 3-6 times faster(if not more) than one compiled without optimizations(like in TCC).

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Orbis terrarum delenda est

Name: Anonymous 2010-07-09 15:40

>>19
I meant you're grasp of the English language, you raging beet roller.

Name: Anonymous 2010-07-09 16:04

>>20
you're

Name: Anonymous 2010-07-09 16:10

>>21
You must be new here.

Name: Anonymous 2010-07-09 16:26

>>19
It has been explicitly pointed out that speed is of no matter in this situation. Are you fucking retarded?

Name: Anonymous 2010-07-09 16:51

-fpeel-loops
That one is only used when using profile data.

Name: Anonymous 2010-07-09 19:23

>>23
Almost no one here can follow a thread of conversation. They have no sense of context and are otherwise socially defective.

Name: Anonymous 2010-07-10 19:43

>>23
YHBFV

Name: Anonymous 2010-11-14 10:26

Name: Anonymous 2011-02-03 23:02

http://gcc.gnu.org/gcc-4.6/changes.html
A new general optimization level, -Ofast has been introduced. It combines the existing optimization level -O3 with options that can affect standards compliance but result in better optimized code. For example -Ofast enables -ffast-math.

-Ofast -funroll-loops -fomit-frame-pointer -fno-exceptions -fomg-optimized

    　　　　　　　　　　　　／￣∧＿∧￣￣￣ //￣＼＼
    　　　　　　＿＿ ⊂／＿＿（´∀｀　）_＿　　/_⊃＿__|　|＼フヽ　　CFLAGS JUST KICKED
    　　　,　 ´＿　　／　　　／￣￣＿_　／￣　ヽ　　　 __ヽ￣￣　|　　IN, YO!
    　　/∠__／―/-。―／――∠＿／＿_∧　　| 　　　　 | ∧＿.|　
    　　,========――´=========＝===/⌒ヽ=|.===＝＝| | ヽ￣〕　
    　 |　＿　　 |GENTOO| 　　＿　″ 　|⌒|　|/　　　_＿ /|　）ノ　　　　vroom
    　）_旧＿∈≡≡≡≡∋＿旧＿″＿||　ノ丿＿ -――┘ 丿　　　　　　vroom!
    　　＼　＼＿ノ￣￣￣三三三＼　＼＿ノ　　　　三三三三　
    　　　　三三三三三三三三三三三三三三三三三三三三三三三三
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Name: Anonymous 2011-02-04 3:09

http://i.imgur.com/bRxfq.jpg

tsk

Name: Anonymous 2011-02-04 3:40

>>25
U mena autism!

Name: Anonymous 2011-02-04 3:41

>>30
10/10

Name: Anonymous 2011-02-04 3:54

>>30
mailto:noko

Name: Anonymous 2011-02-04 7:25

>>29
lol, havent seen this in a while

Name: Anonymous 2011-02-04 7:32

>>30
back to that place where posting images is appropriate, please!

Name: Anonymous 2011-02-04 7:34

"And what about Gentoo? I think that this is the best distribution to run on a 64-bit processor. Perhaps the test needs to be reworded to "without any manual recompiling" and then redone. Compiling all your software yourself, optimized for your processor, gives you a great speed boost. I think this is one major advantage where Linux excels in comparison to Windows."

"Personally, I can tell a difference between my Gentoo install and my previous Redhat install. What's the deal with these people? He can't possibly be right..."

Name: Anonymous 2011-02-04 9:26

>>30
11/10

Name: Anonymous 2012-03-24 7:23

>>30
#define my anus

Name: Anonymous 2012-03-24 11:35

GC is shit.

Name: Anonymous 2012-03-24 18:23

Gentoo is shit.

Newer Posts

CFLAGS Just kicked In

1 Name: Anonymous 2010-07-09 3:20

2 Name: Anonymous 2010-07-09 3:34

3 Name: Anonymous 2010-07-09 3:39

4 Name: HASKAL MEME FAN 2010-07-09 3:52

5 Name: Anonymous 2010-07-09 4:15

6 Name: Anonymous 2010-07-09 5:46

7 Name: Anonymous 2010-07-09 7:59

8 Name: Anonymous 2010-07-09 9:44

9 Name: Anonymous 2010-07-09 12:06

10 Name: Anonymous 2010-07-09 14:23

11 Name: FrozenVoid 2010-07-09 14:46

12 Name: Anonymous 2010-07-09 14:51

13 Name: Anonymous 2010-07-09 14:52

14 Name: Anonymous 2010-07-09 14:55

15 Name: Anonymous 2010-07-09 14:58

16 Name: Anonymous 2010-07-09 15:14

17 Name: FrozenVoid 2010-07-09 15:21

18 Name: Anonymous 2010-07-09 15:27

19 Name: FrozenVoid 2010-07-09 15:36

20 Name: Anonymous 2010-07-09 15:40

21 Name: Anonymous 2010-07-09 16:04

22 Name: Anonymous 2010-07-09 16:10

23 Name: Anonymous 2010-07-09 16:26

24 Name: Anonymous 2010-07-09 16:51

25 Name: Anonymous 2010-07-09 19:23

26 Name: Anonymous 2010-07-10 19:43

27 Name: Anonymous 2010-11-14 10:26

29 Name: Anonymous 2011-02-03 23:02

30 Name: Anonymous 2011-02-04 3:09

31 Name: Anonymous 2011-02-04 3:40

32 Name: Anonymous 2011-02-04 3:41

33 Name: Anonymous 2011-02-04 3:54

34 Name: Anonymous 2011-02-04 7:25

35 Name: Anonymous 2011-02-04 7:32

36 Name: Anonymous 2011-02-04 7:34

37 Name: Anonymous 2011-02-04 9:26

38 Name: Anonymous 2012-03-24 7:23

39 Name: Anonymous 2012-03-24 11:35

40 Name: Anonymous 2012-03-24 18:23