Compiler-Generated Body Functions

When a compiler parallelizes a loop in a function, or a region that has parallelization directives, it creates new body functions that are not in the original source code. These functions are described in Overview of OpenMP Software Execution.

The compiler assigns mangled names to body functions that encode the type of parallel construct, the name of the function from which the construct was extracted, the line number of the beginning of the construct in the original source, and the sequence number of the parallel construct. These mangled names vary from release to release of the microtasking library, but are shown demangled into more comprehensible names.

The following shows a typical compiler-generated body function as displayed in the functions list.

7.415      14.860      psec_ -- OMP sections from line 9 [_$s1A9.psec_]
3.873       3.903      craydo_ -- MP doall from line 10 [_$d1A10.craydo_]

As can be seen from the above examples, the name of the function from which the construct was extracted is shown first, followed by the type of parallel construct, followed by the line number of the parallel construct, followed by the mangled name of the compiler-generated body function in square brackets. Similarly, in the disassembly code, a special index line is generated.

0.       0.            <Function: psec_ -- OMP sections from line 9 [_$s1A9.psec_]>
0.       7.445         [24]    1d8cc:  save        %sp, -168, %sp
0.       0.            [24]    1d8d0:  ld          [%i0], %g1
0.       0.            [24]    1d8d4:  tst         %i1

0.       0.            <Function: craydo_ -- MP doall from line 10 [_$d1A10.craydo_]>
0.       0.030         [ ?]    197e8:  save        %sp, -128, %sp
0.       0.            [ ?]    197ec:  ld          [%i0 + 20], %i5
0.       0.            [ ?]    197f0:  st          %i1, [%sp + 112]
0.       0.            [ ?]    197f4:  ld          [%i5], %i3

With Cray directives, the function may not be correlated with source code line numbers. In such cases, a [ ?] is displayed in place of the line number. If the index line is shown in the annotated source code, the index line indicates instructions without line numbers, as shown below.

                     9. c$mic  doall shared(a,b,c,n) private(i,j,k)
                  
                   Loop below fused with loop on line 23
                   Loop below not parallelized because autoparallelization 
                     is not enabled
                   Loop below autoparallelized
                   Loop below interchanged with loop on line 12
                   Loop below interchanged with loop on line 12
3.873     3.903         <Function: craydo_ -- MP doall from line 10 [_$d1A10.craydo_],
                      instructions without line numbers>
0.        3.903     10.            do i = 2, n-1

Index lines and compiler-commentary lines do not wrap in the real displays.