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Diffstat (limited to 'gas/NOTES')
| -rw-r--r-- | gas/NOTES | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/gas/NOTES b/gas/NOTES deleted file mode 100644 index 18b29b8..0000000 --- a/gas/NOTES +++ /dev/null @@ -1,107 +0,0 @@ --*- text -*- - -PORTING: - -Sorry, no description of the interfaces is written up yet. Look at existing -back ends and work from there. - -New hosts: The configure script, which is generated by autoconf, -should handle all host specific configuration. - -New target formats: Look at the BFD_ASSEMBLER code. The a.out or ELF -code might be a fair example. There are no "good" examples yet, -unfortunately, nor any good documentation of the changes. - -New target processors: Check first to see if the BFD_ASSEMBLER interface is -supported by the file format code you need to use. - -DOCUMENTATION: - -The internals of gas need documenting. - -The documentation should also contain a "Trouble" section similar to gcc's -manual: real bugs, common problems, incompatibilities, etc. - -Anyone want to offer to maintain a man page? - -BFD CONVERSION: - -The "#ifdef BFD_ASSEMBLER" code is on its way in; the "#ifndef BFD_ASSEMBLER" -code is on its way out. The new code uses BFD data structures, and calls BFD -for anything that needs to be written to the output file. The old code did all -the writing itself, or in a couple of cases, used BFD as a slightly higher -level than stdio (i.e., bfd_seek, bfd_write -- these are not the preferred -interface). - -Because of this, some of this code is messy. Lots of ifdef's, and the -non-BFD_ASSEMBLER version often has multiple conditional tests inside it for -various processors or formats. As the various targets get converted over, -these will gradually go away. - -TO DO: - -Remove DONTDEF code, commented-out code. - -Eliminate, as much as possible, anything not in config that is conditionalized -on a CPU, format, or environment. - -Merge COFF support into one version, supporting all the pseudo-ops used in -either versions now, but using BFD for high-level operations. (See second -following item.) Currently there are two versions (plus the new BFD code), -which support different features, and are used on different targets. - -Convert remaining a.out/b.out targets to using the BFD_ASSEMBLER code by -default. - -Finish conversion to using BFD for all object file writing. (This is the -BFD_ASSEMBLER code, not BFD or BFD_HEADERS.) VMS might be the tough one here, -since there's no BFD support for it at all yet. Eliminate the old code. Some -of this can be done target by target, so doing a target where the CPU or -format already supports BFD_ASSEMBLER mode may be easiest. - -Fix lots of uses of empty strings to use null pointers. Will improve -efficiency, and should make code clearer too. - -Clean up comments; lots of 'em are one previous maintainer griping about -another previous maintainer, unrelated to the code. (And with no names, -they're not so fun to read. :-) - -For sparc: "call 0" becomes "jmpl %g0,%l7", and similarly for absolute -addresses in -4096...4095. (Solaris assembler does this. No -relocation required, no absolute symbol needed.) For addresses -outside the range, for COFF, keep generating an absolute symbol to use -for relocs. - -Get Steve to document H8/500 stuff (and others). - -Improve test suite. Incorporate more reported net bugs, and non-confidential -Cygnus customer bugs, and anything else. - -Add support for i386/i486 16-bit mode, so operating system initialization code -doesn't require a separate assembler nor lots of `.byte' directives. - -See if it's more maintainable (and not too much of a performance loss) to use -a yacc grammar for parsing input. The lexer will have to be flexible, and the -grammar will have to contain any construct used on any platform, but it may be -easier to maintain, instead of having code in most of the back ends. - -PIC support. - -Torbjorn Granlund <tege@cygnus.com> writes, regarding alpha .align: - - Please make sure the .align directive works as in digital's assembler. - They fill the space with a sequence of "bis $31,$31,$31;ldq_u $31,0($30)" - since these two instructions can dual-issue. Since .align is ued a lot by - gcc, it is an important optimization. - -(From old "NOTES" file to-do list, not really reviewed:) - -fix relocation types for i860, perhaps by adding a ref pointer to fixS? - -remove the ifdef's from fx_callj tests? - -space tighten sparc alignment? - -md_ => tc_ - -share b.out with a.out. |