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(gcc-295.info)Dispatch Tables

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Output of Dispatch Tables
-------------------------

   This concerns dispatch tables.

`ASM_OUTPUT_ADDR_DIFF_ELT (STREAM, BODY, VALUE, REL)'
     A C statement to output to the stdio stream STREAM an assembler
     pseudo-instruction to generate a difference between two labels.
     VALUE and REL are the numbers of two internal labels.  The
     definitions of these labels are output using
     `ASM_OUTPUT_INTERNAL_LABEL', and they must be printed in the same
     way here.  For example,

          fprintf (STREAM, "\t.word L%d-L%d\n",
                   VALUE, REL)

     You must provide this macro on machines where the addresses in a
     dispatch table are relative to the table's own address.  If
     defined, GNU CC will also use this macro on all machines when
     producing PIC.  BODY is the body of the ADDR_DIFF_VEC; it is
     provided so that the mode and flags can be read.

`ASM_OUTPUT_ADDR_VEC_ELT (STREAM, VALUE)'
     This macro should be provided on machines where the addresses in a
     dispatch table are absolute.

     The definition should be a C statement to output to the stdio
     stream STREAM an assembler pseudo-instruction to generate a
     reference to a label.  VALUE is the number of an internal label
     whose definition is output using `ASM_OUTPUT_INTERNAL_LABEL'.  For
     example,

          fprintf (STREAM, "\t.word L%d\n", VALUE)

`ASM_OUTPUT_CASE_LABEL (STREAM, PREFIX, NUM, TABLE)'
     Define this if the label before a jump-table needs to be output
     specially.  The first three arguments are the same as for
     `ASM_OUTPUT_INTERNAL_LABEL'; the fourth argument is the jump-table
     which follows (a `jump_insn' containing an `addr_vec' or
     `addr_diff_vec').

     This feature is used on system V to output a `swbeg' statement for
     the table.

     If this macro is not defined, these labels are output with
     `ASM_OUTPUT_INTERNAL_LABEL'.

`ASM_OUTPUT_CASE_END (STREAM, NUM, TABLE)'
     Define this if something special must be output at the end of a
     jump-table.  The definition should be a C statement to be executed
     after the assembler code for the table is written.  It should write
     the appropriate code to stdio stream STREAM.  The argument TABLE
     is the jump-table insn, and NUM is the label-number of the
     preceding label.

     If this macro is not defined, nothing special is output at the end
     of the jump-table.