The BSD guys are an interesting crowd. Well they can continue to watch Microsoft and Apple pilfer their software stack usually giving nothing in return while they can use GNOME or KDE or whichever other GPL or LGPLed project exists on their system (takes only a recompile) because otherwise they don't have a useable desktop and are stuck with 1980s user interfaces. I have used clang and it was neither faster to compile nor produced faster code than GCC. The only noticeable thing is the ANSI colored error mes
I see you were modded down as flamebait. However, benchmarks [phoronix.com] would seem to support [phoronix.com] your claim.
C'mon Apple people, please back off the reality distortion. LLVM has a lot of interesting points to recommend it, but one those is very definitely not beating GCC in code optimization. Particularly GCC 4.7 which has turned in yet another impressive performance increment across the board.
C'mon Apple people, please back off the reality distortion. LLVM has a lot of interesting points to recommend it, but one those is very definitely not beating GCC in code optimization.
Not yet - but it's not far behind. The only tests where it varied much were tests where OpenMP was involved, which Clang does not support yet.
Also, back in the day when I used GCC I pretty much never turned on full GCC optimizations because I would run into odd issues at times if I tried. Sure in bench marks GCC is ahead, but how much really world code has GCC enabled with full optimization - especially a brand new GCC version like 4.7?
As you noted LLVM has a lot of other interesting points, and the fact that the optimization is already so close to the existing battle-tested solution is a good reason for more people to migrate to the more flexible architecture of Clang/LLVM ASAP.
The only case where it was not very close was, as I stated originally, where openMP was involved. It's not very surprising that being unable to make use of parallel processing on a multi-core system will set you back in any benchmark.
It's right there in the text below the graphs.
I'm very sorry that pointing out how to read benchmarks has caused you such internal angst you felt compelled to respond three times...
Oh wait, I know you, you're an Apple fanboi/astroturfer. Well I use O3 all the time with GCC and haven't run into an issue in years. Of course, there are issues, just damn few.
In short, anybody who cares about performance runs GCC at O3 these days because it kicks serious butt. And I do know what I'm talking about, I've benchmarked it extensively, and yes, I read the machine code.
If you'd read the comments on your own link it notes that also (a security problem in the linux kernel was caused by an errant optimization).
It was a while ago. However the question stands, how many projects ship with compiler settings that use -O3 by default? The kernel does as it is going for the ultimate in performance, but does KDE or Gnome for example?
What's wrong with GCC? (Score:5, Interesting)
Re: (Score:5, Informative)
The GPL.
Re: (Score:0, Flamebait)
Re: (Score:1)
I see you were modded down as flamebait. However, benchmarks [phoronix.com] would seem to support [phoronix.com] your claim.
C'mon Apple people, please back off the reality distortion. LLVM has a lot of interesting points to recommend it, but one those is very definitely not beating GCC in code optimization. Particularly GCC 4.7 which has turned in yet another impressive performance increment across the board.
Very close though (Score:3)
C'mon Apple people, please back off the reality distortion. LLVM has a lot of interesting points to recommend it, but one those is very definitely not beating GCC in code optimization.
Not yet - but it's not far behind. The only tests where it varied much were tests where OpenMP was involved, which Clang does not support yet.
Also, back in the day when I used GCC I pretty much never turned on full GCC optimizations because I would run into odd issues at times if I tried. Sure in bench marks GCC is ahead, but how much really world code has GCC enabled with full optimization - especially a brand new GCC version like 4.7?
As you noted LLVM has a lot of other interesting points, and the fact that the optimization is already so close to the existing battle-tested solution is a good reason for more people to migrate to the more flexible architecture of Clang/LLVM ASAP.
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it's not far behind
Did you actually look at those benchmarks?
Read your own link. (Score:2)
Did you actually look at those benchmarks?
Yes, did you?
The only case where it was not very close was, as I stated originally, where openMP was involved. It's not very surprising that being unable to make use of parallel processing on a multi-core system will set you back in any benchmark.
It's right there in the text below the graphs.
I'm very sorry that pointing out how to read benchmarks has caused you such internal angst you felt compelled to respond three times...
I'll let you have the last response since
Re: (Score:1)
I am not any kind of "Apple Fanboi".
Care to explain why you always show up in articles involving Apple, turboposting with an obvious bias?
Re: (Score:1)
Oh wait, I know you, you're an Apple fanboi/astroturfer. Well I use O3 all the time with GCC and haven't run into an issue in years. Of course, there are issues, just damn few.
In short, anybody who cares about performance runs GCC at O3 these days because it kicks serious butt. And I do know what I'm talking about, I've benchmarked it extensively, and yes, I read the machine code.
Re: (Score:1)
back in the day when I used GCC I pretty much never turned on full GCC optimizations because I would run into odd issues at times if I tried
Care to be specific about those odd issues? Of course I'm not holding my breath, because I think you just made that up.
Re: (Score:2)
Care to be specific about those odd issues?
Random crashes on -O3.
If you'd read the comments on your own link it notes that also (a security problem in the linux kernel was caused by an errant optimization).
It was a while ago. However the question stands, how many projects ship with compiler settings that use -O3 by default? The kernel does as it is going for the ultimate in performance, but does KDE or Gnome for example?
Re: (Score:2)
Random crashes on -O3.
That is the opposite of specific. Go away troll.
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how many projects ship with compiler settings that use -O3 by default? The kernel does as it is going for the ultimate in performance
You are pulling "facts" out of your ass.
The kernel is built by default with O2 [linux.no], or optionally Os as a configure option.
You do not have the slightest clue what you are talking about in this, or any other post I have seen from you.
Re: (Score:2)
Also, if code optimization is what you want, gcc is not the best C compiler either.