The following example shows an instruction sequence prior to
      optimization:

             addf f7, f8, f9     ; 1
             addf f2, f3, f4     ; 2
             addl r5, r6, r7     ; 3
             addl r8, r9, r10    ; 4

      The assembler optimizes the previous example to a sequence
      similar to the following instruction sequence:

                     :
             addf f7, f8, f9     ; 1
             addl r5, r6, r7     ; 3
             addf f2, f3, f4     ; 2
             addl r8, r9, r10    ; 4
                     :

      If you choose to suppress optimization in the previous example,
      enclose the four instructions with the .BEGIN_EXACT and
      .END_EXACT directives, as shown in the following example:

             .BEGIN_EXACT
             addf f7, f8, f9     ; 1
             addf f2, f3, f4     ; 2
             addl r5, r6, r7     ; 3
             addl r8, r9, r10    ; 4
             .END_EXACT