Flang-new compilation issue with complex(kind=8)

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1

Flang-new fail on complex division on version 19.1.4 (installed using Homebrew on OSX):

program test
integer, parameter :: n=2
complex(kind=8), dimension(n,n) :: V
V(1,1)=cmplx(4.0,2.0)
V(2,2)=cmplx(5.0,3.0)
V(1,2)=0.0
V(2,1)=0.5
PER=cmplx(1.2,1.2)
V(:,:)=V(:,:)/PER
end program test

I got a compilation issue:

alainhebert@Alains-MacBook-Air-2 test_complex % flang-new *.f90
Undefined symbols for architecture arm64:
“___divdc3”, referenced from:
__QQmain in test-8db182.o
ld: symbol(s) not found for architecture arm64
flang-new: error: linker command failed with exit code 1 (use -v to see invocation)

Thank in advance for any help.

1 Like
2

Try adding “-lgcc” , perhaps?

3

I am using clang with flang. I tries without success:

flang-new -L/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib -lclang *.f90

divdc3 still missing.

However, the solution should be close to your proposal. Please continue bringing ideas.

4

What happens if you define PER as COMPLEX? At the moment you appear to be assigning a complex number to a real variable.

5

Same behaviour:

program test
integer, parameter :: n=2
complex(kind=8), dimension(n,n) :: V
complex(kind=8) :: PER
V(1,1)=cmplx(4.0,2.0)
V(2,2)=cmplx(5.0,3.0)
V(1,2)=0.0
V(2,1)=0.5
PER=cmplx(1.2,1.2)
V(:,:)=V(:,:)/PER
end program test

alainhebert@Alains-MacBook-Air-2 test_complex % flang-new test.f90

Undefined symbols for architecture arm64:

“___divdc3”, referenced from:

__QQmain in test-fc2bb3.o

ld: symbol(s) not found for architecture arm64

flang-new: error: linker command failed with exit code 1 (use -v to see invocation)

6

Possibly related? (The page also mentions flang near the bottom of the page)

7

I am confuse because the GitHub post refers to OpenMP. I am not yet using OpenMP. I first want to run my code in scalar mode and test various bindings before going to parallel. Is there a simple way to correct my makefiles to avoid the issue or do I have to wait for a new Homebrew release?

8

I have no experience with Flang-new yet (just searching the net for divdc3 showed the above page), so no idea about the reason (sorry…). But I guess it may be useful to ask LLVM Discourse also (if not yet)

9

Check the contents of /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib. Maybe -lclang is not enough and you need -lclang_rt or something similar.

10

no libclang_rt.dylib. I am afraid that Apple clang is not clang. Someone knows?