#3376 SWAPC error

[Konstantin Kim]

SDCC 4.2.0 #13081 (MINGW64)
sdcc -mpdk14 test.c

__sfr __at(0x10)    _pa;
#define PA          _pa

volatile char foo;
void main() {
    for(;;) {
        __asm;
            sr          _foo
            swapc.io    __pa, #0
        __endasm;
        if (PA&1) foo ^= 0x8e;  //lfsr
    }
}

got "test.asm:111: Error: machine specific addressing or addressing mode error"

[Konstantin Kim]

can someone reproduce/confirm the bug ?

[Philipp Klaus Krause]

I can reproduce the issue using sdcc from current svn on my amd64 Debian GNU/Linux testing system. I suspect this could be fixed in the assembler relatively easily, by what is different for swapc vs. other instructions that have an .io variant. But I don't know, and I'm not that familiar with the assemblers. Patches are welcome.

[Free-PDK]

looks like the assembler emit function for swapc was called with plain op (without the extra options) and therefore the mandatory falg "PDK_OPCODE_ADR_IO" was not present.

patch for pdk14 and pdk15 (pdk13 does not have swapc and pdk16 implementation is missing it):

% svn diff
Index: aspdk14/pdk14mch.c
===================================================================
--- aspdk14/pdk14mch.c  (revision 13761)
+++ aspdk14/pdk14mch.c  (working copy)
@@ -222,7 +222,7 @@

         case S_SWAPC:
               def.mask = 0x3F;

-              eswapc(op, def, /*N offset*/6);
+              eswapc(opWithFlags, def, /*N offset*/6);
               break;

         case S_COMP:
Index: aspdk15/pdk15mch.c
===================================================================
--- aspdk15/pdk15mch.c  (revision 13761)
+++ aspdk15/pdk15mch.c  (working copy)
@@ -219,7 +219,7 @@

         case S_SWAPC:
               def.mask = 0x7F;

-              eswapc(op, def, /*N offset*/7);
+              eswapc(opWithFlags, def, /*N offset*/7);
               break;

         case S_COMP:

[Philipp Klaus Krause]

Thanks. the patch looks good to me (though I am not an assembler expert), and regression tests pass (but they don't use swapc anyway).
I've applied the patch in [r13768].
It would be good if someone finishes the pdk16 assembler and linker. Nikolas, who did most of the work on pdk assemblers and linkers AFAIK isn't around anymore.

[Philipp Klaus Krause]

Please check if the fix in [r13768] works for you.

[Konstantin Kim]

thanks, it works