flang vs gfortran compiling same code with -flto flag flang runs into /usr/bin/ld: /usr/bin/../lib/LLVMgold.so: error loading plugin: /usr/bin/../lib/LLVMgold.so: cannot open shared object file: No such file or directory

[iajzenszmi]

flang vs gfortran compiling same code with -flto flag flang runs into /usr/bin/ld: /usr/bin/../lib/LLVMgold.so: error loading plugin: /usr/bin/../lib/LLVMgold.so: cannot open shared object file: No such file or directory

(base) ian@ian-Aspire-One-753:~/CodeCode/CodeCode$ flang xspline.f -flto -o xspline /usr/bin/ld: /usr/bin/../lib/LLVMgold.so: error loading plugin: /usr/bin/../lib/LLVMgold.so: cannot open shared object file: No such file or directory flang-7: error: linker command failed with exit code 1 (use -v to see invocation) (base) ian@ian-Aspire-One-753:~/CodeCode/CodeCode$ gfortran xspline.f -flto -o xspline (base) ian@ian-Aspire-One-753:~/CodeCode/CodeCode$ ./xspline SECOND - DERIVATIVES FOR SIN(X) FROM 0 TO PI SPLINE ACTUAL ANGLE 2ND DERIV 2ND DERIV 0.16 -0.156832 -0.156434 0.31 -0.309631 -0.309017 0.47 -0.454933 -0.453991 0.63 -0.588991 -0.587785 0.79 -0.708561 -0.707107 0.94 -0.810683 -0.809017 1.10 -0.892844 -0.891007 1.26 -0.953009 -0.951057 1.41 -0.989721 -0.987688 1.57 -1.002061 -1.000000 1.73 -0.989715 -0.987688 1.88 -0.953020 -0.951056 2.04 -0.892835 -0.891006 2.20 -0.810685 -0.809017 2.36 -0.708558 -0.707107 2.51 -0.588999 -0.587785 2.67 -0.454920 -0.453990 2.83 -0.309660 -0.309017 2.98 -0.156736 -0.156434 3.14 -0.000075 0.000000 (base) ian@ian-Aspire-One-753:~/CodeCode/CodeCode$ (base) ian@ian-Aspire-One-753:~/CodeCode/CodeCode$ cat xspline.f PROGRAM XSPLINE C PAGE 33 NUMERICAL RECIPIES EXAMPLE BOOK SECOND EDITION. C DRIVER FOR ROUTINE SPLINE INTEGER N REAL PI PARAMETER(N=20,PI=3.141593) INTEGER I REAL YPI, YPN, X(N),Y(N),Y2(N) WRITE(,) 'SECOND - DERIVATIVES FOR SIN(X) FROM 0 TO PI' C GENERATE ARRAY FOR INTERPOLATION C DO 11 I=1,20 X(I)=IPI/N Y(I)=SIN(X(I)) 11 CONTINUE C C CALCULATE 2ND DERIVATIVE WITH SPLINE C YP1=COS(X(1)) YPN=COS(X(N)) CALL SPLINE(X,Y,N,YP1,YPN,Y2) C TEST RESULT WRITE(,'(T19,A,T35,A)') 'SPLINE','ACTUAL' WRITE(,'(T6,A,T17,A,T33,A)') 'ANGLE','2ND DERIV','2ND DERIV' DO 12 I = 1, N WRITE(,'(1X,F8.2,2F16.6)') X(I),Y2(I),-SIN(X(I)) 12 CONTINUE END PROGRAM SUBROUTINE SPLINE(X,Y,N,YP1,YPN,Y2) PARAMETER (NMAX=100) DIMENSION X(N),Y(N),Y2(N),U(NMAX) IF (YP1.GT..99E30) THEN Y2(1)=0.0 U(1)=0.0 ELSE Y2(1)=-0.5 U(1)=(3./(X(2)-X(1)))((Y(2)-Y(1))/(X(2)-X(1))-YP1) ENDIF DO 11 I=2,N-1 SIG=(X(I)-X(I-1))/(X(I+1)-X(I-1)) P=SIGY2(I-1)+2. Y2(I)=(SIG-1.)/P U(I) = (6.((Y(I+1)-Y(I))/(X(I+1)-X(I))-(Y(I)-Y(I-1)) * /(X(I)-X(I-1)))/(X(I+1)-X(I-1))-SIGU(I-1))/P 11 CONTINUE IF (YPN.GT..99E30) THEN QN=0. UN=0. ELSE QN=0.5 UN=(3./(X(N)-X(N-1)))(YPN-(Y(n)-Y(N-1))/(X(N)-X(N-1))) ENDIF Y2(N)=(UN-QNU(N-1))/(QN*Y2(N-1)+1.) DO 12 K=N-1,1,-1 Y2(K)=Y2(K)*Y2(K+1)+U(K) 12 CONTINUE RETURN END SUBROUTINE (base) ian@ian-Aspire-One-753:~/CodeCode/CodeCode$

[bryanpkc]

You need to make sure that the LLVM build can generate LLVMgold.so. If I remember correctly, you need to make sure that binutils headers (specifically plugin-api.h) can be found on the system; on Ubuntu that would require running apt install binutils-dev. You might need to point LLVM's CMake files at the location of the header with the variable LLVM_BINUTILS_INCDIR. Finally, you should probably also enable building lld when configuring LLVM, by adding lld to LLVM_ENABLE_PROJECTS when running CMake.