Whenever I try to compile any C++ program with march=native on a Macbook with a M1 chip, I get the following error when using clang:
clang: error: the clang compiler does not support '-march=native'
However, it used to work on an older Macbook with an Intel CPU. Does clang not support this architecture (yet)?
clang --version gives:
Apple clang version 12.0.0 (clang-1200.0.32.29)
Target: arm64-apple-darwin20.2.0
In Apple clang version 13.0.0, -mcpu=apple-m1 is now available.
$ clang --print-supported-cpus
Apple clang version 12.0.5 (clang-1205.0.22.9)
Target: arm64-apple-darwin20.5.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
Available CPUs for this target:
a64fx
apple-a10
apple-a11
apple-a12
apple-a13
apple-a14
apple-a7
apple-a8
apple-a9
apple-latest
apple-s4
apple-s5
carmel
cortex-a34
cortex-a35
cortex-a53
cortex-a55
cortex-a57
cortex-a65
cortex-a65ae
cortex-a72
cortex-a73
cortex-a75
cortex-a76
cortex-a76ae
cortex-a77
cortex-a78
cortex-x1
cyclone
exynos-m3
exynos-m4
exynos-m5
falkor
generic
kryo
lightning
neoverse-e1
neoverse-n1
saphira
thunderx
thunderx2t99
thunderx3t110
thunderxt81
thunderxt83
thunderxt88
tsv110
vortex
-mcpu=apple-a14 might be the best one for M1.
As far as I know this is not Apple M1 specific, it occurs also with clang for various other architectures (mostly various other arm processors).
e.g. See this bug report here https://github.com/DMOJ/judge-server/issues/303
Basically every build of clang for a new architecture must choose to provide defaults for "march=native" for the target for which the compiler is built or not; and if not then you will see this error message. Even for those arm processors who do have optimisation targets you often have to use specifically "-mcpu=xxx" instead of "-march".
e.g. For the iphone you would use -mcpu=apple-a11 -mcpu=apple-a12 etc.
However no such target has been implemented yet for Apple M1
In Clang 15, -march=native now exists for Apple M1 (I personally use it).
another solutions is update clang with brew
lang: error: the clang compiler does not support '-march=native'
1° - Install llvm con brew
brew install llvm
2° - Check clang version
cd /opt/homebrew/opt/llvm
.clang --version
Result:
Homebrew clang version 15.0.6
Target: arm64-apple-darwin22.2.0
Thread model: posix
InstalledDir: /opt/homebrew/opt/llvm/bin
3° - modify path with the new version, for example add to .zshrc
export PATH="/opt/homebrew/opt/llvm/bin:$PATH"
Related
My mac version is Sierra. Xcode 8.0
gcc info
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin16.4.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
I think gcc is not problem. My project build option is -print-multi-os-directory. but my gcc unsupported... what's the problem???
thanks
on mac your GCC is Clang as you may see in output
in clang option -print-multi-os-directory is unsupported
On current trunk (line 2079)
Was marked as unsupported here
You may try to install pure gcc via brew install gcc command
Also why do you need this option? Do you have any special checks in you project ?(this option just print path )
Since you are trying to build binutils:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=bfd/configure;h=97693870c462d5e5231bd2b512a76b7c271b9133;hb=7fa393306ed8b93019d225548474c0540b8928f7#l10348
Try to figure out why you get in condition when multi-os option is used.
This happened because your compiler passed test:
I'm trying to use the Undefined Behavior Sanitizer by building like this
gcc -fsanitize=undefined add.c -o add
also
clang -fsanitize=undefined -O add.c -o add
In both cases, I'm getting a file not found error:
ld: file not found: /Library/Developer/CommandLineTools/usr/bin/../lib/clang/8.0.0/lib/darwin/libclang_rt.ubsan_osx_dynamic.dylib
This is the output I get when running gcc -v and clang -v
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
According to this news release, it is available in GCC and also the original homepage for it says it's been merged into LLVM. The linked to article says GCC 4.9 has it, which I assume I have (at least --the version numbering seems different but the article was written a few years ago and I have updated my system several times).
Question: how can I build an executable to use UBSan?
According to blog Friday Q&A 2015-07-03: Address Sanitizer
by Mike Ash:
Any idea why Apple clang doesn't support -fsanitize=undefined?
When I try that I get:
clang -fsanitize=undefined ub.c
...
ld: file not found: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/
bin/../lib/clang/8.0.0/lib/darwin/libclang_rt.ubsan_osx_dynamic.dylib
Spencer at 2016-12-21 01:23:59:
If you use -fsanitize=address,undefined it works. Hopefully this
helps anyone else who finds this post search for that error like I did.
Its not an ideal solution for us since they are separate components, and we have limited control over the environment and tools. We had to suspend some Address Sanitizer testing because Asan produces incorrect results with GCC inline assembly and use of ebp/rbp as a general purpose register. And here, the environment and tools are provided by Travis CI.
A bug report was filed with LLVM at Issue 33201, Apple Clang bundled with Xcode 8 does not reject -fsanitize=undefined when it should. It may be closed as off-topic since its an Apple Clang bug (we don't have an iTunes account to file the bug with Apple).
In order to use the undefined behavior sanitizer, I had to install and build LLVM with clang as well as libcxx and libcxxabi, even though my MacOS already came with a version of clang. (with the result that I now I have two versions of clang installed on my computer). From the llvm getting started page
cd where-you-want-llvm-to-live
svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm
cd where-you-want-llvm-to-live
cd llvm/tools
svn co http://llvm.org/svn/llvm-project/cfe/trunk clang
cd where-you-want-llvm-to-live
svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx
svn co http://llvm.org/svn/llvm-project/libcxxabi/trunk libcxxabi
Now, I can use the undefined behavior sanitizer by running
/usr/local/bin/clang -fsanitize=undefined -O add.c -o add
I am confused by what version of gcc is installed on my Mac, which is has OS X Yosemite (10.10.5) installed on it. I also have Xcode v6.3.1 installed.
Entering the commands below reveals the following info:
gcc -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/c++/4.2.1
Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)
Target: x86_64-apple-darwin14.5.0
Thread model: posix
clang -v
Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)
Target: x86_64-apple-darwin14.5.0
Thread model: posix
which gcc
/usr/bin/gcc
which clang
/usr/bin/clang
As far as I can tell, gcc is not aliased to clang.
Can someone please enlighten me what this means?
In newer versions of XCode gcc and clang are linked to the same binary in the SDK. clang will say that it's at least gcc 4.2, this is a little weird, but works for lots of software that checks for gcc and it is compatible in general.
echristo#dzur ~> /usr/bin/clang -v
Apple LLVM version 7.3.0 (clang-703.0.31)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
echristo#dzur ~> /usr/bin/gcc -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/c++/4.2.1
Apple LLVM version 7.3.0 (clang-703.0.31)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
If you take a look at the directory InstalledDir you can see the programs that are actually there.
I had a similar problem, I wanted to know what version of gcc should I install on my Yosemite, since most of UNIX tools need GCC it is a vital package.
if gcc -version doesn't shows the version, it means you do not have one.
you need to install a gcc first, then check for its version! funny? but according to your Xcode command line and OS version you have not a lot of options, let the brew decide which version you should install, It also installs dependencies.
To install GCC,
install Homebrew From HomeBrew Website
Open Terminal
Run command: brew install gcc
I have installed my GCC just now, here is the snapshot, notice the dependent module names and the gcc version at the following picture, they are Yosemite tailored :
I'd like to use the -fsanitize=address features of clang.
I'm on:
OS X 10.9.1 with Xcode 5.0.2
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
I'm running clang from the command line, and I'm getting the error:
clang: error: unsupported argument 'address' to option 'fsanitize='
I'm told this works, but searching around hasn't shown me the way; do I need to bring in a different version of clang?
Thanks!
The out-of-box version of clang on OS X does not implement support of Address Sanitizer. You will have to build your own version of clang from sources.
You need a different build of clang than the one apple gave you. The simplest way to get one (or more) is to install Homebrew http://brew.sh
and then
brew install llvm --with-asan
You could also try a prebuilt clang from http://llvm.org/releases/download.htm.
It's by no means impossible to build clang 'by hand', but last I checked it did take multiple checkouts to get the source tree. The other options should have you asaning in minutes.
I typed this in my terminal:
llvm-gcc --version
But what I have is this :
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix`
Am I not able to interpret this block of statements? or did I forget to enable something on my system?
Nothing is wrong. The situation is just a little confusing.
Apple no longer distributes GCC with Xcode. They now use Clang as the default (and only!) compiler on Mac OS X. cc, gcc, and clang (as well as the C++ variants, c++, g++, and clang++) are now all linked to run clang under current versions of Xcode.
The version of clang you're running is, per the --version output, 500.2.79.
If you want to install GCC as an alternative to clang, you can do so using a variety of methods, including one using Homebrew:
https://github.com/mxcl/homebrew/wiki/Custom-GCC-and-cross-compilers