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Diffstat (limited to 'gcc/README.NS32K')
| -rw-r--r-- | gcc/README.NS32K | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/gcc/README.NS32K b/gcc/README.NS32K index 93c5beaef54..8e3610e33b5 100644 --- a/gcc/README.NS32K +++ b/gcc/README.NS32K @@ -1,6 +1,55 @@ This file describes the implementation notes of the GNU C Compiler for the National Semiconductor 32032 chip (and 32000 family). +Much of this file was obsolete. It described restrictions caused by +bugs in early versions of of the ns32032 chip and by bugs in sequent +assemblers and linkers of the time. + +Many (all?) of the chip bugs were fixed in later revisions and +certainly fixed by later chips in the same series (ns32332 and +ns32532). + +Conditional code to support sequent assembler and/or linker restrictions +has not been removed deliberately, but has probably not been tested in +a *very* long time. + +Support for one sequent assembler bug has *not* been retained. +It was necessary to say: + + addr _x,rn + cmpd _p,rn + +rather than: + + cmpd _p,@_x + + +This used to be forced by the use of "rmn" register constraints rather +than "g". This is bad for other platforms which do not have this +restraint. + +It is likely that there are no Balance 8000's still in operation, but +if there are and the assembler bug was never fixed then the easiest +way to run gcc would be to also run gas. + +The code required by the sequent assembler is still generated when the +-fpic flag is in effect and this is forced by the appropriate +definition of LEGITIMATE_PIC_OPERAND_P. If support for the old sequent +assembler bug is required, then this could be achieved by adding the +test from LEGITIMATE_PIC_OPERAND to the GO_IF_LEGITIMATE_ADDRESS +definition. Of course, this should be conditional on something in the +sequent.h config file. + +The original contents of this file appear below as an historical note. +SEQUENT_ADDRESS_BUG mentioned below has been replaced by +INDEX_RATHER_THAN_BASE. Note that merlin.h still defines +SEQUENT_ADDRESS_BUG even though it is not used anywhere. Since it has +been like this for a long time, presumably either the +SEQUENT_ADDRESS_BUG is not required for the merlin, or no one is using +gcc on the merlin anymore. + +HISTORICAL NOTE + The 32032 machine description and configuration file for this compiler is, for NS32000 family machine, primarily machine independent. However, since this release still depends on vendor-supplied |